WPHS - Region 14



WPHS

Chemistry

Unit 5 Packet

Stoichiometry

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Bergmann-Sams

Chemistry: Unit 5 Outline: Stoichiometry

|Assignment |Must be done in class |

|Podcast 5.1 | |

|Worksheet 5.1 | |

|Lab: Simple Weight Loss | |

|Podcast 5.2 (OPTIONAL/AS NEEDED) | |

|Worksheet 5.2 | |

|Podcast 5.3 | |

|Worksheet 5.3 | |

|Lab: Vinegar—NaHCO3 | |

|Podcast 5.4 | |

|Worksheet 5.4 | |

|Lab: Limiting Reactant Exploration Lab | |

|Lab: Limiting Reactant Lab | |

|Podcast 5.5 | |

|Worksheet 5.5 | |

|Take Home Lab (Cookies-Optional) | |

|Unit 5 Reviewsheet | |

|Unit 5 Vocabulary | |

|Lab Exam | |

|Unit 5 Exam | |

Unit 5: Vocabulary

Stoichiometry

Limiting reagent/limiting reactant

Excess reagent/excess reactant

Theoretical yield

Actual yield

Percent yield

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(OPTIONAL) Take Home Lab: Making Chocolate Chip Cookies Name

The following recipe for chocolate chip cookies recently appeared in Chemical & Engineering News (C&EN, Jun 19, 1995, p. 100). It was attributed to Jeannene Ackerman of Witco Corp.

Ingredients:

|1 |587.5 cm3 gluten | |

|2 |4.9 cm3 NaHCO3 | |

|3 |4.9 cm3 refined halite | |

|4 |176.25 cm3 partially hydrogenated tallow triglyceride | |

|5 |177.45 cm3 crystalline C12H22O11 | |

|6 |177.45 cm3 unrefined C12H22O11 | |

|7 |4.9 cm3 methyl ether of protocatechuic aldehyde | |

|8 |Two calcium carbonate-encapsulated avian albumen-coated protein | |

|9 |473.2 cm3 theobroma cacao | |

|10 |236.6 cm3 de-encapsulated legume meats (sieve size #10) | |

To a 2-L jacketed round reactor vessel (reactor #1) with an overall heat-transfer coefficient of about 100 Btu/F-ft2-hr add one, two, and three with constant agitation.

In a second 2-L reactor vessel with a radial flow impeller operating at 100 rpm add four, five, six, and seven until the mixture is homogeneous.

To reactor #2 add eight followed by three equal portions of the homogeneous mixture in reactor #1. Additionally, add nine and ten slowly with constant agitation. Care must be taken at this point in the reaction to control any temperature rise that may be the result of an exothermic reaction.

Using a screw extrude attached to a #4 nodulizer place the mixture piece-meal on a 316SS sheet (300 x 600 mm). Heat in a 460K oven for a period of time that is in agreement with Frank & Johnston's first order rate expression (see JACOS, 21, 55), or until golden brown.

Once the reaction is complete, place the sheet on a 25ºC heat-transfer table allowing the product to come to equilibrium.

Conversion Factors

1 teaspoon = 5cm3

235 cm3 = 1 cup

ºC = 9/5ºF +32

To Receive Credit: You must have a signed note from your parent/guardian that indicates that you made the cookies –you can even bring in a sample to your friendly Chemistry Teacher.

PROBLEMS: Use dimensional analysis to set up the problem. Please show your work!

1. Show your work here for how much of each item you need to measure out at home:

2. How many cookies did you made from this recipe?

3. If you only have 100cm3 of unrefined C12H22O11, how much gluten will you need?

4. You have decided with a group of friends to make these cookies for a fund raiser. It is your job to make 1000 cookies. How many calcium carbonate-encapsulated avian albumen-coated protein will you need to buy?

5. Adjust the recipe for 3 calcium carbonate-encapsulated avian albumen-coated protein and determine how much of each reactant you need in the recipe.

STOICHIOMETRY LAB—Simple Weight Loss

|A balanced equation indicates the proportions between reactants and products. More specifically, the coefficients in the |

|equation indicate the mole ratios between the chemical substances. Thus, it is possible to determine how much product will |

|be produced from a given amount of reactant. This predicted amount can then be compared with the actual amount produced to |

|determine the percent yield of the reaction. |

|In this experiment, you will investigate two reactions: |

|Copper and aqueous silver nitrate yield silver and aqueous copper(II) nitrate. |

|Sodium bicarbonate and aqueous sulfuric acid produce aqueous sodium sulfate, water, and carbon dioxide gas. |

SAFETY

• 2M sulfuric acid can cause burns. Avoid skin and eye contact. Rinse spills with plenty of water.

PROCEDURE

1. Obtain a beral pipet containing 2M H2SO4.

2. Obtain a clean, dry flask. Measure and record its mass. Place approximately 0.30g of NaHCO3 into the flask. Find the combined mass of the flask and sodium bicarbonate and record.

3. Determine the exact mass of sodium bicarbonate by subtraction. This mass must be between 0.20 and 0.40 g. Record the mass of sodium bicarbonate in a data table.

4. Record the TOTAL mass of all the components of the lab: sodium bicarbonate, flask, dropper and sulfuric acid.

5. SLOWLY, drop by drop, add the sulfuric acid to the sodium bicarbonate to generate carbon dioxide gas. Continue releasing the acid in this manner until gas production ceases.

6. Measure and record the TOTAL mass of all the components again (like in step 4).

7. Return the beral pipet with the remainder of the sulfuric acid. Rinse the contents of the flask down the drain with water. Clean up your lab station.

DATA

Construct a data table for each reaction to display your laboratory measurements. Make sure that each value is clearly labeled.

ANALYSIS

1. Write a balanced equation for the reaction.

2. Calculate the actual mass of carbon dioxide produced (“actual yield”).

3. Using the balanced equation, calculate the mass of carbon dioxide that should be produced from the mass of sodium bicarbonate that you used (“theoretical yield”).

CONCLUSIONS

• Calculate the percent yield of the carbon dioxide using the equation below (show your work).

|% yield = |experimental yield |( 100 |

| |theoretical yield | |

| | | |

| | | |

| | | |

| | | |

| | | |

| | | |

| | | |

• A perfect percent yield would be 100%. Comment on your degree of accuracy and suggest possible sources of measurement error. How could these errors be reduced in the future?

Limiting Reactant Exploration Lab: How much Carbon Dioxide?

Introduction:

In this lab you will do a cool reaction, make some measurements, make a graph, and then write down some observations. The reaction that you will do is the reaction between vinegar and baking soda. In this reaction, carbon dioxide, CO2 will be produced. Chemists use chemical symbols to show the reaction. The reaction is:

|CH3COOH (aq) |+ |NaHCO3 |( |H2O |+ |CO2 |+ |NaCH3COO |

|Vinegar | |Baking | |Water | |Carbon | |Sodium |

| | |Soda | | | |Dioxide | |Acetate |

Materials:

• Apparatus as pictured below

• Vinegar

• Baking Soda

To simplify: Here is a picture of what you will need:

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Procedure:

Follow this procedure as closely as possible.

1. place 0.25 g into a paper towel

2. Get the appropriate amount of vinegar into the flask

3. Set-up the apparatus—and mix.

4. Record the amount of CO2 collected

Data

Fill out the following data table:

| |Amount of vinegar |Amount of baking soda |Vol CO2 |

|1 |1 mL |0.25g | |

|2 |2 mL |0.25g | |

|3 |3 mL |0.25g | |

|4 |4 mL |0.25g | |

|5 |5 mL |0.25g | |

|6 |6 mL |0.25g | |

HAVE YOUR TEACHER SIGN HERE IMMEDIATELY AFTER COLLECTING DATA

Questions

1. Describe in detail what occurred (your observations) when the vinegar was mixed with the baking soda. Some descriptive words that you should probably use are, but not including (gas given off, fizzing, foaming, balloon expanding)

2. Describe the pattern of how much carbon dioxide, CO2 was formed as you added more and more vinegar. Relate this to the graph.

3. For each trial: explain which substance was the limiting and excess reagent. Explain how you were able to determine this.

4. You should have noticed that as you increased the amount of vinegar eventually you got the same amount of carbon dioxide, CO2. Explain why that occurred.

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Chemistry

Limiting Reactant Lab

Introduction

A limiting reactants is defined as one of the reactants in a chemical reaction that will be used up first. The purpose of this lab is to determine the amount of precipitate that will be produced when a given amount of calcium chloride and sodium sulfate are mixed.

Once you have massed the calcium chloride and the sodium sulfate you will need to do each of the following before you proceed with the rest of the experiment.

• Write the balanced chemical reaction noting the states of matter for all substances. (See solubility chart to determine which substance precipitates.)

• Determine which reagent, calcium chloride or sodium sulfate, is limiting.

• Predict the amount of the precipitate that will be produced.

Once you have done these three things, show them to your instructor. Then you may begin the experiment.

Procedure

1. Label and mass a test tube. The test tube must be completely dry

2. Obtain about 0.30 grams of each reagent (It doesn’t matter how much you get just as long as you know exactly how much you obtain), and determine both which reagent is limiting and how much precipitate you will discover.

3. Dissolve the calcium chloride into 3 mL of deionized water by carefull flicking the test tube (Your instructor will show you how to do this. Dissolve the sodium sulfate into 3-mL of deionized water.

4. Pour the sodium sulfate solution into the test tube with calcium chloride in it. Take care to get all of the sodium sulfate into the calcium chloride test tube.

5. Remove the stopper and then place your sample into a centrifuge and spin out the precipitate. (Caution should be used in using this device. Your teacher will instruct you on proper use of a centrifuge)

6. Decant, or pour off, the liquid (supernatant) above the precipitate. Be careful not to allow any of the precipitate to be poured out.

7. Add about 10-mL of deionized water to your precipitate and spin it again. Decant again and repeat this step two more times for a total of four centrifuges

8. SHOW YOUR PRODUCT TO YOUR TEACHER AND GET HIS SIGNATURE. Set your labeled test tube into a drying oven overnight.

9. Weigh your test tube and determine the mass of the precipitate that you have. SHOW YOUR PRODUCT TO YOUR TEACHER AND GET HIS SIGNATURE AGAIN. Compare this amount to what you expected to get from your calculations.

Calculations

Show all calculations needed to determine the expected amount of precipitate required to do the experiment. This should include the balanced chemical reaction and all appropriate stoichiometric calculations.

Questions

1. Why did you have to mass the test tube prior to beginning the experiment?

2. Why did you need to add water to the solid calcium chloride and solid sodium sulfate to cause the reaction to occur?

3. Comment on sources of error.

4. What was your percentage of error?

5. Draw a picture of the two test tubes prior to adding the two chemicals. What had happened to the calcium chloride? What happened to the sodium sulfate.

6. Now draw a picture of the test tube once you have mixed the two chemicals. Where are all of the chemicals now? Label this in your diagram.

Worksheet 5.1 Stoichiometry

1. Carbon disulfide is an important industrial solvent. It is prepared by the reaction of coke with sulfur dioxide:

5C(s) + 2SO2(g) -----> CS2(s) + 4CO(g)

a. How many moles of CS2 form when 6.3 mol of C reacts?

b. How many moles of carbon are needed to react with 7.24 moles of SO2

2. Silver can be made according to the following equation:

___AgNO3+ ___Ca ( ___Ca(NO3)2 + ___Ag

❑ Balance the equation

❑ If 35.3 moles of silver nitrate are reacted how many moles of silver are produced?

3. Barium oxide reacts with carbon dioxide to make Barium carbonate:

___BaO + ___CO2 ( ___BaCO3

❑ Balance the equation

❑ If 23.4 moles of barium oxide react, how many liters of CO2 are required at STP?

4. Car batteries are called lead storage batteries because of their use of large quantities of lead. These batteries utilize the following equation.

Pb + PbO2 +2H+ + 2HSO4- ( 2PbSO4 + 2 H2O

❑ If 34.3-g of PbO2 react how many grams of water will be formed?

❑ Assuming the same mass of PbO2, how many grams of PbSO4 will be formed?

5. Ammonia, (NH3) is produced by reacting its elements with each other according to the following equation:

___N2 + ___H2 ( ___NH3

❑ Balance the equation.

❑ If 34.3-L of nitrogen is reacted with hydrogen, how many liters at STP of ammonia will be formed?

6. 32.5-g of ZnSO4 reacts to form how many grams of BaSO4 according to the following equation. Don’t forget to balance the equation.

___ZnSO4 + ___BaCl2 ( ___BaSO4 + ___ZnCl2

7. When sodium metal is added to water the resulting gas, Hydrogen can often explode. How many Liters of hydrogen gas is produced when 41.2-g of sodium is dropped into water. Again, you must balance the equation in order to solve the problem.

___Na + ___HOH ( ___NaOH + ___H2

8. Propane is a gas used often for backyard grills. How many Liters of CO2 is produced when 54.9-L of propane (C3H8) is burned according to the following equation. Again, you must balance the equation in order to solve the problem.

___C3H8 + ___O2 ( ___CO2 + ___H2O

Worksheet 5.2 More Stoichiometry

1. How many moles of Carbon dioxide is formed when 44-mol of CH4 is burned?

2. 43.5-grams of barium sulfate is formed from the reaction of barium nitrate and sodium sulfate. How many moles of sodium sulfate reacted?

3. 32.3-L of O2 is formed when KClO3 is decomposed. How many moles of KClO3 reacted initially?

__KClO3 ( __KCl + __O2

4. 22.8-g of NaOH is reacted with hydrochloric acid. How many grams of water is formed?

5. 32.5-grams of iron III chloride reacts with silver nitrate. How many grams of silver chloride are formed?

6. 43.5-grams of copper II sulfate is reacted with barium nitrate. How many grams of precipitate are formed?

7. How many liters of hydrogen gas is formed when 13.5-grams of calcium reacts with sulfuric acid (H2SO4)?

8. Calculate the mass of silver needed to react with chlorine to produce 84 g of silver chloride.

9. A volume of 7.5 L of hydrogen gas was produced from the single replacement reaction of zinc and nitric acid (HNO3). Calculate the mass of zinc needed for this reaction.

10. How many molecules of chlorine are needed to react with 5.6 g of iron to form iron III chloride?

Worksheet 5.3 Limiting Reactants

BOX ALL ANSWERS!!

1. When 114.0 g of iron and 292.7 g of chlorine gas reacts, iron(III) chloride is formed.

a. Write a balanced equation

b. How many grams of Iron (III) chloride is formed

c. What is the limiting reactant?

d. How much excess reagent is left over at the end of the experiment?

2. 20 L of oxygen react with 1.0L of methyl alcohol, CH3OH

a. Write a balanced equation

b How many liters of water will be formed at STP?

c. What is the limiting reactant?

d. How much excess reagent is left over at the end of the experiment?

3. 25 g of hydrazine, N2H4(l), and 66 g of hydrogen peroxide, H2O2(l), react to produce nitrogen gas and water.

a. Write a balanced equation

b. How many grams of nitrogen are produced?

c. What is the limiting reactant?

d. How much excess reagent is left over at the end of the experiment?

4. 22.5 grams of lithium reacts with 33.5 grams of aqueous aluminum sulfate. This is a single replacement reaction.

a. Write a balanced equation.

b. How many grams of lithium sulfate will be formed?

c. What is the limiting reactant?

d. How much excess reagent is left over at the end of the experiment?

5. 33.6 grams of sulfur dioxide reacts with 55.3 grams of water to form sulfurous acid (H2SO3).

a. Write a balanced equation.

b. How many grams of sulfurous acid will be formed?

c. What is the limiting reactant?

d. How much excess reagent is left over at the end of the experiment?

6. 77 g of potassium iodide react with 32 g of lead II nitrate reacts to form a yellow precipitate.

a. Write a balanced equation and identify the precipitate

b. How many grams of the precipitate will be formed?

c. What is the limiting reactant?

d. How much excess reagent is left over at the end of the experiment?

Worksheet 5.4 Percent Yield

1. 15.5-g of NH4Cl reacts with an excess of AgNO3. In the reaction 35.5-g AgCl is produced. NH4NO3 is the other product. What is the percent yield?

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2. Potassium Chlorate decomposes according to the following reaction.

2KClO3 ( 2KCl +3O2

❑ In an experiment 32.5-g of KClO3 is decomposed and 15.2-g of KCl is formed. What is the percent yield?

3. Nitrogen gas reacts with hydrogen gas to make ammonia (NH3). 15.5-L of N2 reacts at STP to make 30-L of ammonia. What is the percent yield?

4. What is the percent yield of oxygen gas if 54L of O2 can be obtained from the thermal decomposition of 500.0 g of potassium chlorate?

KClO3 ( KCl + O2

5. It is desired to prepare 100.0g of silicon tetrafluoride by adding hydrogen fluoride to silicon dioxide. The percent yield of this process is 75%. Ho much HF do you need to react? The other product is water.

6. When black gunpowder explodes, potassium nitrate, carbon, and sulfur react with each other to form nitrogen gas, carbon dioxide gas, and solid potassium sulfide. If the original mixture contains 50.0 g of potassium nitrate, if the total volume of the gases is 20L, then what is the percent yield for this process?

7. Very hot zinc will react with steam to form zinc oxide and hydrogen. 5.4L of H2 was used to use up 20.0 g of zinc completely? What is the percent yield of this process?

Worksheet 5.5 Molar Mass Worksheet Name _________________

1. 2.35g of metal with a charge of +2 reacts with hydrochloric acid to produce 0.598 L of gas at STP. What metal do you have?

M + HCl ( MCl2 + H2

2. (NH4)3PO4 reacts with 0.0345 g of metal sulfate (M2(SO4)3) to produce 0.0399 g of (NH4)2SO4. Balance the equation. What is the molar mass of the metal? What is the metal?

__M2(SO4)3 + __(NH4)3PO4 ( __(NH4)2SO4 + __MPO4

3. 3.45g of a metal hydroxide with charge + 1 reacts with excess Iron III Chloride to make 0.82g of Iron III hydroxide. What is the identity of the metal hydroxide?

4. 30.2 L of oxygen is produced at STP when 135.9 g of metal chlorate of charge +3 decomposes into oxygen and the metal chloride. What is the identity of the metal chlorate?

Unit 5 Reviewsheet

1. How many grams of water are formed when 12.5-g of hydrogen reacts with oxygen?

2. How many liters of carbon dioxide are formed when 12.3-g of sodium carbonate reacts with 2.0-L of hydrogen chloride. The reaction is printed below:

___Na2CO3 + ___HCl ( ___NaCl + ___H2O + ___CO2

3. How many grams of precipitate are formed when 24.3-g of zinc nitrate reacts with 20.5-g of sodium phosphate?

4. How many liters of oxygen are produced when 3.25-g of KClO3 decomposes into KCl and O2?

5. When 2.25-g of sodium chloride reacts with excess silver nitrate, 3.45-g of precipitate is formed. What is the percent yield of the precipitate?

6. 4.35-g of C5H12 reacts with 4.0-L of O2.

a. How many liters of CO2 are formed?

b. How much excess reactant remains?

7. 3.0-g of zinc reacts with silver nitrate to form how many grams of zinc nitrate?

8. 8.2-mol of barium carbonate decomposes into how many moles of barium oxide. The other product is carbon dioxide.

9. 4.5-g of sodium hydroxide reacts with 2.0-g of sulfuric acid (H2SO4). How many grams of water are formed?

10. 8.0-L of butane (C4H10) reacts with oxygen to make 50-g of carbon dioxide. What is the percent yield?

11. 8.5-L of hydrogen reacts with 5.4-L of nitrogen to make…

a. how many liters of ammonia (NH3)?

b. How many liters of excess reactant remains?

12.A 2.25-g sample of aluminum sulfate reacts with 3.25-g of sodium phosphate to make 1.0-g of precipitate. What is the percent yield?

Stoichiometry Worksheet 1 KEY

1. Carbon disulfide is an important industrial solvent. It is prepared by the reaction of coke with sulfur dioxide:

5C(s) + 2SO2(g) -----> CS2(s) + 4CO(g)

❑ How many moles of CS2 form when 6.3 mol of C reacts?

❑ How many moles of carbon are needed to react with 7.24 moles of SO2

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2. Silver can be made according to the following equation:

2AgNO3+ Ca( Ca(NO3)2 + 2Ag

35.3g ?g

❑ Balance the equation

❑ If 35.3 moles of silver nitrate are reacted how many moles of silver are produced?

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3. Barium oxide reacts with carbon dioxide to make Barium carbonate:

BaO + CO2 -( BaCO3 (Balanced)

23.4mol L?

❑ Balance the equation

❑ If 23.4 moles of barium oxide react, how many liters of CO2 are required at STP?

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4. Car batteries are called lead storage batteries because of their use of large quantities of lead. These batteries utilize the following equation.

Pb + PbO2 +2H+ + 2HSO4- (2PbSO4 + 2 H2O

34.3g g?

❑ If 34.3-g of PbO2 react how many grams of water will be formed?

❑ Assuming the same mass of PbO2, how many grams of PbSO4 will be formed?

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5. Ammonia, (NH3) is produced by reacting its elements with each other according to the following equation:

N2 + 3H2 ( 2NH3

34.3L L?

❑ Balance the equation.

❑ If 34.3-L of nitrogen is reacted with hydrogen, how many liters at STP of ammonia will be formed?

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6. 32.5-g of ZnSO4 reacts to form how many grams of BaSO4 according to the following equation. Don’t forget to balance the equation.

ZnSO4 + BaCl2 ( BaSO4 + ZnCl2 bal

32.5g g?

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7. When sodium metal is added to water the resulting gas, Hydrogen can often explode. How many Liters of hydrogen gas is produced when 41.2-g of sodium is dropped into water. Again, you must balance the equation in order to solve the problem.

2Na + 2HOH ( 2NaOH + H2

41.2g L?

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8. Propane is a gas used often for backyard grills. How many Liters of CO2 is produced when 54.9-L of propane (C3H8) is burned according to the following equation. Again, you must balance the equation in order to solve the problem.

C3H8 + 5O2 ( 3CO2 + 4H2O

54.9L L?

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Stoichiometry WS B Name

Period

1. How many moles of Carbon dioxide is formed when 44-mol of CH4 is burned?

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2. How many moles of calcium phosphate is formed when 32.5-mols of calcium nitrate reacts with sodium phosphate?

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3. 43.5-grams of barium sulfate is formed from the reaction of barium nitrate and sodium sulfate. How many moles of sodium sulfate reacted?

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4. 32.3-L of O2 is formed when KClO3 is decomposed. How many moles of KClO3 reacted initially?

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5. 2.5-mol of water is made from its elements. How many particles of hydrogen reacted?

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6. 22.8-g of NaOH is reacted with hydrochloric acid. How many grams of water is formed?

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7. 32.5-grams of iron III chloride reacts with silver nitrate. How many grams of silver chloride are formed?

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8. 34.5-grams of Lithium reacts with Chromium III chloride. How many grams of lithium chloride is formed?

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9. 43.5-grams of copper II sulfate is reacted with barium nitrate. How many grams of precipitate are formed?

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10 How many liters of hydrogen gas is formed when 13.5-grams of calcium reacts with sulfuric acid?

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11. 45.6-L of H2 is formed when zinc is reacted with nitric acid. How many grams of zinc reacted?

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12. 14.5-g of cesium explosively reacts with water to form hydrogen and cesium hydroxide. How many molecules of hydrogen were formed?

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13. Calculate the mass of silver needed to react with chlorine to produce 84 g of silver chloride.

|2Ag |+ |Cl2 |( |2AgCl |

|? | | | |84g |

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14. A volume of 7.5 L of hydrogen gas was produced from the single replacement reaction of zinc and nitric acid (HNO3). Calculate the mass of zinc needed for this reaction.

|Zn |+ |2HCl |( |ZnCl2 |+ |H2 |

|g? | | | | | |7.5L |

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15. How many molecules of chlorine are needed to react with 5.6 g of iron to form iron III chloride?

|3Cl2 |+ |2Fe |( |2FeCl3 |

|Molec? | |5.6g | | |

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16. What mass of ammonia, NH3, is necessary to react with 2.1 x 1024 molecules of oxygen when ammonia (NH3) reacts with oxygen to form water and nitrogen dioxide?

|4NH3 |+ |7O2 |( |4NO2 + 6H2O |

|g? | |2.1 x 1024 molec | | |

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17. Calculate the volume of carbon dioxide produced when 250 g of pentane, C5H12, burn. Assume the carbon dioxide is cooled to STP.

|C5H12 |+ |8O2 |( |5CO2 |+ |6H2O |

|250g | | | |?L | | |

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18. Nitrogen gas reacts with oxygen to form dinitrogen trioxide. How many molecules of oxygen are needed to make 5.5 L of N2O3 at STP?

|2N2 |+ |3O2 |( |2N2O3 |

| | |molec? | |5.5L |

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19. Silver Nitrate reacts with sodium chloride to make the silver chloride and sodium nitrate. When 2.53 grams of silver nitrate is reacted. How many grams of silver chloride are formed?

|AgNO3 |+ |NaCl |( |AgCl |+ |NaNO3 |

|2.53g | | | |?g | | |

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20. Methane (CH4) is burned in air. When 50.6 L of methane is burned how many grams of carbon dioxide will be formed?

|CH4 |+ |2O2 |( |CO2 |+ |2H2O |

|50.6L | | | |?g | | |

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21. Calcium Carbonate decomposes into calcium oxide and a common gas. When 45.5 grams of calcium oxide is formed how many liters of gas is also formed from this reaction.

|CaCO3 |( |CaO |+ |CO2 |

| | |45.5g | |?L |

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22. When 3.25 g of copper II nitrate reacts with ammonium hydroxide. How many grams of the precipitate will form.

|Cu(NO3)2 |+ |2NH4OH |( |Cu(OH)2 (s) |+ |2NH4NO3 (aq) |

|3.25g | | | |?g=ppt | | |

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Limiting Reactant Worksheet

Do all work on a separate sheet of paper and

BOX ALL ANSWERS!!

1. When 114.0 g of iron and 292.7 g of chlorine gas reacts, iron(III) chloride is formed.

a. Write a balanced equation

b. What is the limiting reactant?

c. How many grams of Iron (III) chloride is formed

a. How much excess reagent is left over at the end of the experiment?

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2. 20 L of oxygen react with 1.0L of methyl alcohol, CH3OH

a. Write a balanced equation

b. What is the limiting reactant?

c How many liters of water will be formed at STP?

d. How much excess reagent will be left over?

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• 3. 25 g of hydrazine, N2H4(l) and 66 g of hydrogen peroxide, H2O2 (l) react exothermically to produce nitrogen gas and water.

a. Write a balanced equation

b. What is the limiting reactant?

c. How many grams of nitrogen are produced?

d. How much excess reagent is left over?

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4. 22.5 grams of lithium reacts with a 33.5 grams of aqueous aluminum sulfate according to a single replacement reaction.

a. Write a balanced equation.

b. What is the limiting reactant?

c. How many grams of lithium sulfate will be formed?

d. How much excess reagent will remain?

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5. 33.6 grams of sulfur dioxide reacts with 55.3 grams of water to form sulfurous acid.

a. Write a balanced equation.

b. What is the limiting reactant?

c. How many grams of sulfurous acid will be formed?

d. How much excess reagent will remain?

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6. 77 g of potassium iodide react with 32 g of Lead II nitrate reacts to form a yellow precipitate.

a. Write a balanced equation and identify the precipitate

b. What is the limiting reactant?

c. How many grams of the precipitate will be formed?

d. How much excess reagent will remain?

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*7. In the following equation:

NH3 + O2 ---> H2O + NO2,

a. Balance the equation

b. What is the limiting reactant?

c. If you react 22 L of NH3 with 95 L of air (Which is 20% oxygen), how many liters of NO2, will be produced?

d. How much excess reagent will remain?

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WS D: Percent Yield Worksheet

1. 15.5-g of NH4Cl reacts with an excess of AgNO3. In the reaction 35.5-g AgCl is produced. NH4NO3 is the other product. What is the percent yield?

|NH4Cl |+ |AgNO3 |( |AgCl |+ |NH4NO3 |

|15.5g | | | |35.5g | | |

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2. Potassium Chlorate decomposes according to the following reaction.

2KClO3 ( 2KCl +3 O2

❑ In an experiment 32.5-g of KClO3 is decomposed and 15.2-g of KCl is formed. What is the percent yield?

|2KClO3 |( |2KCl |+ |3O2 |

|32.5g | |15.2g | | |

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3. Nitrogen gas reacts with hydrogen gas to make ammonia (NH3). 15.5-L of N2 reacts at STP to make 30-L of ammonia. What is the percent yield?

|N2 |+ |3H2 |( |2NH3 |

|15.5L | | | |30L |

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4. The Haber and Caude processes are methods by which ammonia (NH3) is synthesized from its elements (H2 and N2) What is the percent yield if 5.0-kg of ammonia (in Kilograms) is to be expected when 4000.0 L of nitrogen are used in these procedures?

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5. What is the percent yield of oxygen gas if 54L of O2 can be obtained from the thermal decomposition of 500.0 g of potassium chlorate?

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6. It is desired to prepare 100.0g of silicon tetrafluoride by adding hydrogen fluoride to silicon dioxide. The percent yield of this process is 75%. Ho much HF do you need to react?

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7. When black gunpowder explodes, potassium nitrate, carbon, and sulfur react with each other to form nitrogen, carbon dioxide, and potassium sulfide. If the original mixture contains 50.0 g of potassium nitrate, if the total volume of the gases is 20L, what is the percent yield for this process?

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8. Very hot zinc will react with steam to form zinc oxide and hydrogen. 5.4L of H2 was used to use up 20.0 g of zinc completely? What is the percent yield of this process?

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WS E Molar Mass Worksheet KEY Name _________________

1. 2.35g of metal with a charge of +2 reacts with hydrochloric acid to produce 0.598 L of gas at STP. What metal do you have?

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2. (NH4)3PO4 reacts with 0.0345 g of metal sulfate (M2(SO4)3) to produce 0.0399 g of (NH4)2SO4. Balance the equation. What is the molar mass of the metal? What is the metal?

__M2(SO4)3 + 2(NH4)3PO4 ( 3(NH4)2SO4 + 2MPO4

0.0345g 0.0456g

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3. 3.45g of a metal hydroxide with charge + 1 reacts with excess Iron III Chloride to make 0.82g of Iron III hydroxide. What is the identity of the metal hydroxide?

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4. 30.2L of oxygen is produced at STP when 135.9 g of metal chlorate of charge +3 decomposes into oxygen and the metal chloride. What is the identity of the metal chlorate?

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Mixed Stoichiometry Worksheet KEY

1. How many grams of water are formed when 12.5-g of hydrogen reacts with oxygen?

|2H2 |+ |O2 |( |2H2O |

|12.5g | | | |?g |

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2. How many liters of carbon dioxide are formed when 12.3-g of sodium carbonate reacts with 2.0-L of hydrogen chloride. The reaction is printed below:

Na2CO3 + HCl ( NaCl + H2O + CO2

|Na2CO3 |+ |2HCl |( |2NaCl |+ H2O |+ CO2 |

|12.3g | |2.0L | | | |L? |

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3. How many grams of precipitate are formed when 24.3-g of zinc nitratre reacts with 20.5-g of sodium phosphate?

|3Zn(NO3)2 |+ |2Na3PO4 |( |Zn3(PO4)2 |+ |6NaNO3 |

|24.3g | |20.5g | |?g (ppt) | | |

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4. How many liters of oxygen are produced when 3.25-g of KClO3 decomposes into KCl and O2?

|2KClO3 |( |2KCl |+ |3O2 |

|3.25g | | | |L? |

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5. When 2.25-g of sodium chloride reacts with excess silver nitrate, 3.45-g of precipitate is formed. What is the percent yield?

|NaCl |+ |AgNO3 |( |AgCl |+ |NaNO3 |

|2.25g | | | |3.45g | | |

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6. 4.35-g of C5H12 reacts with 4.0-L of O2.

a. How many liters of CO2 are formed?

b. How much excess reactant remains?

|C5H12 |+ |8O2 |( |5CO2 |+ |6H2O |

|4.35g | |4.0L | |L? | | |

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7. 3.0-g of zinc reacts with silver nitrate to form how many grams of zinc nitrate?

|Zn |+ |2AgNO3 |( |Zn(NO3)2 |+ |2Ag |

|3.0g | | | |?grams? | | |

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8. 8.2-mol of barium carbonate decomposes into how many moles of barium oxide. The other product is carbon dioxide.

|BaCO3 |( |BaO |+ |CO2 |

|8.2mol | |?mol | | |

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9. 4.5-g of sodium hydroxide reacts with 2.0-g of sulfuric acid (H2SO4). How many grams of water are formed?

|2NaOH |+ |H2SO4 |( |2HOH |+ |Na2SO4 |

|4.5g | |2.0g | |G? | | |

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10. 8.0-L of butane (C4H10) reacts with oxygen to make 50-g of carbon dioxide. What is the percent yield?

|2C4H10 |+ |13O2 |( |8CO2 |+ |10H2O |

|8.0L | | | |50g | | |

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11. 8.5-L of hydrogen reacts with 5.4-L of nitrogen to make…

a. how many liters of ammonia (NH3)?

b. How many liters of excess reactant remains?

|3H2 |+ |1N2 |( |2NH3 |

|8.5L | |5.4L | |?L |

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12. ** 2.25-g of aluminum sulfate reacts with 3.25-g of sodium phosphate to make 1.0-g of precipitate. What is the percent yield?

|Al2(SO4)3 |+ |2Na3PO4 |( |2AlPO4 |+ |3Na2SO4 |

|2.25g | |3.25g | |1.0g | | |

This is both a limiting reactant problem and a percent yield problem

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Chapter 10 Review

EHS Chemistry

1. 23.5-g of KClO3 decomposes in the following way:

KClO3 ( KCl + O2

How many grams of O2 was forms? (Make sure to balance the equation)

2. In the reaction:

Na2CO3 + H3PO4 ( Na3PO4 + H2O + CO2

How many grams of Na2CO3 react with the H3PO4 to produce 100L of CO2 at STP?

3. Mercury (II) oxide decomposes to form liquid mercury and oxygen gas. If 5.4 g of mercury (II) oxide decomposes, how many grams of mercury is formed? (Hint: You must start with a correctly balanced chemical reaction)

4. 2.5-g of C4H10 reacts with 0.59-L of O2 at STP to form CO2 and H2O.

a. Write the balanced equation.

b. How many grams of H2O will be formed?

c. How much excess reactant remains?

5. 2.30-g of Barium chloride reacts with 5.45-g of sodium carbonate in a double displacement reaction. How many grams of precipitate will form? (Hint: These are the calculations for the lab that you did). Make sure to use the table of solubilites to determine which substance is the solid precipitate.

6. 32.5-g of Hg(NO3)2 reacts with NH4Cl to make HgCl2 and NH4NO3. When the chemicals were mixed it was discovered that 20.0-g of HgCl2 was formed. What is the percent yield?

7. BONUS: 2.52x1025 atoms of sodium react with 325-L of phosphoric acid gas (H3PO4) at STP. 302.5-L of a gas is given off. What is the percent yield of the reaction?

Chapter 10 Review KEY

EHS Chemistry

1. 23.5-g of KClO3 decomposes in the following way:

KClO3 ( KCl + O2

How many grams of O2 was forms? (Make sure to balance the equation)

|2KClO3 |( |2KCl |+ |3O2 |

|23.5g | | | |G? |

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2. In the reaction:

Na2CO3 + H3PO4 ( Na3PO4 + H2O + CO2

How many grams of Na2CO3 react with the H3PO4 to produce 100L of CO2 at STP?

|3Na2CO3 |+ |2H3PO4 |( |2Na3PO4 |+ |3HOH |+ |3CO2 |

|?g | | | | | | | |100L |

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3. Mercury (II) oxide decomposes to form liquid mercury and oxygen gas. If 5.4 g of mercury (II) oxide decomposes, how many grams of mercury is formed? (Hint: You must start with a correctly balanced chemical reaction)

|2HgO |( |2Hg |+ |O2 |

|5.4g | |?g | | |

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4. 2.5-g of C4H10 reacts with 0.59-L of O2 at STP to form CO2 and H2O.

a. Write the balanced equation.

b. How many grams of H2O will be formed?

c. How much excess reactant remains?

|2C4H10 |+ |13O2 |( |8CO2 |+ |10H2O |

|2.5g | |0.59L | | | |?g |

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5. 2.30-g of Barium chloride reacts with 5.45-g of sodium carbonate in a double displacement reaction. How many grams of precipitate will form? (Hint: These are the calculations for the lab that you did). Make sure to use the table of solubilites to determine which substance is the solid precipitate.

|BaCl2 |+ |Na2CO3 |( |BaCO3 |+ |2NaCl |

|2.30g | |5.45g | |?g:ppt | | |

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6. 32.5-g of Hg(NO3)2 reacts with NH4Cl to make HgCl2 and NH4NO3. When the chemicals were mixed it was discovered that 20.0-g of HgCl2 was formed. What is the percent yield?

|Hg(NO3)2 |+ |2NH4Cl |( |HgCl2 |+ |2NH4NO3 |

|32.5g | | | |20.0g | | |

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7. BONUS: 2.52x1025 atoms of sodium react with 325-L of phosphoric acid gas (H3PO4) at STP. 302.5-L of a gas is given off. What is the percent yield of the reaction?

|6Na |+ |2H3PO4 |( |2Na3PO4 |+ |3H2 |

|2.52E25 | |325L | | | |302.5L |

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WS E Molar Mass Worksheet KEY Name _________________

1. (NH4)3PO4 reacts with 0.0345 g of metal sulfate (M2(SO4)3) to produce 0.0456 g of (NH4)2SO4. Balance the equation. What is the molar mass of the metal? What is the metal?

__M2(SO4)3 + 2(NH4)3PO4 ( 3(NH4)2SO4 + 2MPO4

0.0345g 0.0456g

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2. 2.35g of metal with a charge of +2 reacts with hydrochloric acid to produce 0.598 L of gas at STP. What metal do you have?

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3. 3.45g of a metal hydroxide with charge + 1 reacts with excess Iron III Chloride to make 0.82g of Iron III hydroxide. What is the identity of the metal hydroxide?

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4. 30.2L of oxygen is produced at STP when 135.9 g of metal chlorate of charge +3 decomposes into oxygen and the metal chlorate. What is the identity of the metal chloride?

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Representative Particles of A

Gas A not at STP

L of Solution A

L of gas A at STP

Grams of A

Representative Particles of B

Gas B not at STP

L of Solution B

L of gas B at STP

Grams of B

The Land of The Mole

Moles of A

Moles of B

Stoichiometry Flowchart

Avogadro’s #

Avogadro’s #

Molar Mass

Mole Ratio

22.4 L

22.4 L

PV = nRT

PV = nRT

Molarity

Molarity

Molar Mass

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