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Chemistry: Fall Final Review 2013 ANSWERS

Chapter 1 & 3 – Introduction to chemistry

What are the safety rules for goggles, chemical safety, lab procedure, fire safety, diluting acids, etc.

Review general safety rules; remember to dilute an acid always pour acid into water

2) Draw a picture of the disposal, toxic, open flame, extreme temperature, and sharp object safety symbols.

|Disposal |Toxic |Open Flame |Extreme temp |Sharp object |

|[pic] |[pic] |[pic] |[pic] |[pic] |

Define chemistry: Chemistry – the study of the structure and composition of matter

Define the following types of data:

a. Qualitative: deals with the type of substances

b. Quantitative: deals with the amount of substances

Define mass, mater, and weight.

a. Mass: the amount of matter in an object

b. Matter: anything with mass and takes up space

c. Weight: measurement of the force of gravity upon a mass

Define and describe the states of matter.

a. Solid: definite shape and volume

b. Liquid: definite volume, indefinite shape

c. Gas: no definite shape or volume

Compare and give examples of the types of

Properties:

|Physical |Chemical |

|can be observed using your |The ability of a substance to |

|senses (color, melting point, |change into one or more new |

|state of matter, etc.) |substances (reactivity, |

| |flammability, toxicity, ect.) |

Compare and give examples of the types of

Changes:

|Physical |Chemical |

|Observable change that does not|occur when something new is |

|change the substance (breaking,|produced (burning, tarnishing, |

|crushing, folding, bending, |reacting, etc.) |

|cutting) | |

Define and give 2 examples of the different properties:

a. Intensive: Properties INDEPENDENT of amount. Ex) color, density, boiling pt, melting pt, flammability, toxicity

b. Extensive: Properties that depend on amount. Ex) mass, length, volume,

What is a mixture?

Physical blend of 2 or more pure substances in any proportion in which each substance retains its individual properties

Compare and give examples of the

Types of Matter:

|Elements |Compounds |

|Elements are made of only one |Compounds are made of more than|

|type of atom. |one type of atom in a specific |

|Ex) Silver, gold, iron, O2, N2,|ratio |

|helium |Ex) NaCl, CO2, H2O, C6H12O6 |

Compare and give examples of the

Types of Mixtures:

|Heterogeneous |Homogeneous |

|you can see the different parts|you can’t see the different |

|Ex) green salad, vegetable |parts |

|soup, orange juice, sand & |Ex) salt water, vinegar, apple |

|water |juice, air, metal alloys like |

| |brass |

Describe the separation techniques of mixtures

a. Distillation: separation of two liquids (based different on boiling points)

b. Filtration: separation of a solid and liquid

c. Crystallization: forms a solid structure

What are the four evidences that a chemical reaction has taken place?

Bubbles, heat change, color change, precipitate formed

Define and give an example of the law of conservation of mass.

4 C3H5(NO3)3 α 4 CO2 + 6 N2 + 10 H2O + 9 O2

Matter cannot me created or destroyed. The mass of the starting reactants will equal the mass of the products made.

Chapter 2 – Dimensional Analysis & Measurement

What would 38 000 000 000 be in scientific notation? 3.8 x 1010

Subtract 1.2 x107 – 9.1 x106 = 2.9 x 106

Multiply (1x103) x (5 x10-1) = 5 x 102

Define the rules for significant figures. (can be in your own words)

a. All digits 1-9 always count

b. “sandwich” zeros always count

c. “leading” zeros after a decimal do not count

d. “trailing” zeros after a number without a decimal do not count.

e. “final” zeros after a number AND a decimal count

How many sig figs are in:

1.70 0.00550 20,000 10900 8.0370 x10-2

Significant figures = 3 3 1 3 5

Define precision and accuracy. Give an example of a measurement that is precise but not accurate.

Precise measurements are close to each other

Accurate measurements are close to the actual value

22) You measure the length of your desk and get that it is 35.5 cm long. It is actually 41.2 cm long. What is the percent error of your measurement? (% Error = Accepted – Measured x 100%)

Accepted

| 41.2cm – 35.5cm | x 100% = 5.7 cm x 100% = 13.8% error

41.2 cm 41.2 cm

Fill in the Chart:

|Prefix |Decimal meaning |Saying |Example |

|Kilo- |1000 units |King |kilometer km |

|Hecto- |100 units |Henry |hectometer hm |

|Deka- |10 units |Died |decameter dam |

|Base Unit |1 unit |By |meter m |

|Deci- |0.1 units |Drinking |decimeter dm |

|Centi- |0.01 units |Chocolate |centimeter cm |

|Milli- |0.001 units |Milk |millimeter mm |

How many liters are in 12.7 kL? 12,700 Liters

Convert 22.5 L to mL. 22,500 mL

Use dimensional analysis to convert 22.5 km/hr into m/sec.

22.5 km x 1000 m x 1 hour x 1 min = 6.25 m/s

1 hour 1 km 60 min 60 sec

What is the density in g/ml of a substance that has a mass of 3.99 g and a volume of 0.88 ml? (D = m/v)

D = m D = 3.99 g D = 4.53 g/mL

V 0.88 mL

What is the volume of a liquid that has a density of 2.25 g/ml and a mass of 18.7 g?

V = m V = 18.7 g V = 8.31 mL

D 2.25 g/mL

Chapter 4 – Atomic Structure

Fill in the Chart:

|Scientist |Contribution |Model (draw picture) |

|Dalton |Elements are composed of tiny indivisible particles called atoms |[pic] |

| |all atoms of the same element are identical | |

| |atoms can combine in whole number ratios to form compounds | |

| |atoms can mix physically or combine chemically | |

|J. J. Thompson |Discovered electrons in 1897 |[pic] |

| |Plum Pudding Model – atoms had electrons scattered in a positive “pudding-like” substance | |

| | | |

|Rutherford |Rutherford shot particles through a thin piece of gold foil in 1911; |[pic] |

| |Determined that the atom is mostly empty space, but the there is a dense center that he called the | |

| |nucleus. | |

| |Rutherford’s Model – included a positive nucleus at center of negative substance. | |

|Bohr |Bohr Model – showed electrons in concentric energy levels (orbits) around the positive nucleus. |[pic] |

Name and describe the most current atomic model.

Quantum Mechanical Model – shows the probable locations of electrons using the solutions from Schrodinger’s equations. Mathematical model based on probability.

Fill in the Chart:

|Particle |Symbol |Charge |Location |

|Proton |p+ |+1 |nucleus |

|Neutron |n0 |0 |nucleus |

|Electron |e- |-1 |Orbiting around the nucleus |

What 2 things does the atomic number give you for a neutral atom?

a. The number of protons

b. The number of electrons

Define atomic mass.

The weighted average mass of the isotopes of that element

Define mass number.

Mass number = # of protons + # of neutrons

35) How do you find the number of neutrons in an atom if you know the mass number? How many neutrons are in carbon-14?

# neutrons = mass # - atomic # 14 – 6 = 8 neutrons in Carbon 14

What is an isotope?

Isotopes of an element have a different mass number and a different number of neutrons

Fill in the Chart:

|Type |Symbol |Atomic # Change |Neutron Change |Mass Change |

|Alpha |42α +2 |-2 |-2 |-4 |

|Beta |0-1e- |+1 |-1 |0 |

|Gamma |00γ |0 |0 |0 |

1. Alpha (α) – an alpha particle is 2 protons and 2 neutrons (42α)

Ex. 21084Po 20682Pb + 42α

2. Beta (β) – a beta particle is the lost of an electron (a neutron is converted to a proton) (0-1e-)

Ex. 146C 147N + 0-1e-

3. Gamma (γ) – a gamma particle is a photon at high frequency

Ex. 3115P* 3115P + γ

Label both pictures:

Calculate the average atomic mass for Copper using the following information:

69% abundance Copper - 63 (mass = 62 .930 g/mole) (69/100)*(62.930g) = 43.422g

31% abundance Copper - 65 (mass = 64 .930 g/mole) (31/100)*(64.930g) = 20.128g +

63.550 g

Chapter 5 - Electrons

What is the formula for the speed of light? Identify all symbols and constants.

c = λν c: the speed of light = 3.0 x108 m/s

λ: symbol for wavelength = distance between 2 waves in meters (m)

ν: symbol for frequency = number of waves per second in Hertz (Hz)

What is the frequency of a wave if its wavelength is 2.054 x 10-9 m?

ν = c/λ ’ 3.00 x108 m/s ÷ 2.054 x 10-9 m = 1.46 x1017 Hz

What is the formula for the Energy of a photon? Identify all symbols and constants.

E = h ν E: energy in Joules (J)

h: Planck’s constant = 6.626 x 10-34 J/s

ν: symbol for frequency = number of waves per second in Hertz (Hz)

What is the energy of a wave if the frequency is 5.46 x 108 Hz?

E = h ν Ε ’ (6.626 x10-34 J/s) x (5.46 x 108 Hz) = 3.62 x10-25 J

Identify the relationships as direct or inverse:

a. Wavelength : frequency inverse λ( ν(

b. Frequency : Energy direct ν( Ε(

45) What is the electromagnetic spectrum? Made of different forms of EM waves and is based on the frequency and wavelengths of the waves

Label the EM spectrum in order:

___________ ____________ ___________ __Visible light_ ___________ ___________ ___________

47) Define atomic emission spectra. What does it tell us about the atoms of elements? A set of frequencies of electromagnetic waves given off by atoms of an element

48) Define valence electrons of an atom? The electrons in the outermost orbital. Help determine an atoms properties

How many valence electrons are in N, Cl and Na?

N: _5___ Cl: __7__ Na: __1__

50) What is the Octet rule? Atoms lose or gain or share electrons in order to acquire a full set of 8 valence electrons. (first shell has 2 valence electrons but all others have 8)

Define Aufbau’s principle. Give an example. Electrons enter orbitals of the lowest energy first.

52) Define the Heisenberg Uncertainty Principle. It is not possible to know precisely both the velocity and the position of a particle at the same time.

53) Define Pauli Exclusion Principle. Give an example. No 2 electrons in the same atom can have the same set of 4 quantum numbers. They must have opposite spins. ( (

54) Define Hund’s Rule. Give an example using nitrogen. Electrons in the same sublevel occupy available orbitals singly before pairing up (1 e- per orbital till each orbital has one then begin putting a 2nd e- in each orbital) Empty Bus Seat Rule

Draw the orbital notation for chlorine. ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( _

1s 2s 2p 2p 2p 3s 3p 3p 3p

In 2s1, what do the 2, the s, and the 1 represent?

2 = the energy level

s = the sublevel type

1 = the number of electrons occupying the sublevel

What is the abbreviated electron configuration of lead? [Xe] 6s2 4f14 5d10 6p2

Write out the unabbreviated stable electron configuration of Copper. (Remember, it’s an exception!)

1s2 2s2 2p6 3s2 3p6 4s1 3d10

59) In order to become stable, an element with an electron configuration of 1s2 2s2 2p6 3s2 3p6 4s2 will most likely ____. d) lose 2 electrons

Draw the Lewis dot structure for N, K, & Cl-.

N K Cl- (chloride ion)

Chapter 6/7 – Periodic Table

61) How was Mendeleev’s periodic table arranged? How was Mosley’s periodic table arranged? Whose version do we use now?

• Mendeleev arranged by increasing atomic mass

• Mosley arrange by increasing atomic number (number of protons) ***modern version

62) What are the Group 1A elements called? Group 2A? Group 7A? Group 8A? What kind of elements are in Groups 3-12?

Group 1A – Alkali Metals

Group 2A – Alkaline Earth Metals

Group 17 (Group 7 A) – Halogens

Group 18 (Group 8 A) – Noble Gases

Groups 3-12 – Transition Elements

Give 2 ways that elements are grouped on the periodic table?

• Same number of valence electrons

• Similar chemical and physical properties

What do elements in a row have in common? Same number of principle energy levels (energy shells)

65) What do elements in a column have in common? Same number of valence electrons, similar chemical properties

How does the number of valence electrons affect an element’s reactivity? It determines how reactive an element is and what it will bond to.

What is the trend for atomic radius? What element has the largest atomic radius?

Atomic radius increases from top to bottom on the periodic table and it increases from right to left.

The largest atomic radius is Francium

68) Place in increasing radius: neutral carbon, a carbon cation and a carbon anion? Why are they in that order?

Carbon cation < Carbon atom < carbon anion

The cation lost electrons and gets smaller than the neutral atom. The anion gains electrons, therefore, getting larger than the neutral atom.

What is ionization energy? What is its trend? Which element has the highest ionization energy?

Ionization energy is the amount of energy it takes to remove an electron from an atom. Ionization energy increases from bottom to top and it also increases from left to right on the periodic table.

Helium has the highest ionization energy.

What is the trend in electronegativity? Where are the elements with the smallest electronegativity?

Electronegativity increases from left to right (not including the noble gases) and it increases from top to bottom. The smallest electronegativity elements are the noble gases; the biggest is Fluorine.

What are some common properties of metals? Nonmetals?

|Metals |Nonmetals |

|Lose electrons |Found right of zig-zag plus Hydrogen |

|Lustrous = shiny “metallic” appearance |Gain electrons easily |

|Conduct heat and electricity |Poor conductors of heat and electricity |

|Solids at room temperature – except mercury (Hg) |Brittle solids |

|High melting points and high densities |Little or no metallic luster, various colors |

|Malleable = able to be hammered into shapes | |

|Ductile = able to be drawn into wire | |

Chapter 8 – Ionic Bonding

Define cation. Cation – a positive ion resulting from the loss of electrons

Define anion. Anion – a negative ion resulting from the gain of electrons

Define Oxidation Number. The charge on an ion after the number of electrons has changed.

Gaining three electrons results in what overall charge? -3 charge

Compare the number of elements, formula naming, and give an example for:

|Binary compound |Ternary Compound |

|Contains 2 elements |Contains 3 or more elements |

|Ends in “-ide” |Usually ends in “-ate” |

|NaCl – sodium chloride |NaClO3 – sodium chlorate |

Name the following compounds:

CaCl2 Calcium Chloride

NH4NO2 Ammonium Nitrate

CuNO3 Copper (I) Nitrate

Ba(C2H3O2)2 Barium Acetate

SnS2 Tin (IV) Sulfide

Write the formula for the following:

zinc bromide ZnBr

lead (IV) oxide Pb2O

copper (I) carbonate Cu2CO3

calcium fluoride CaF2

magnesium sulfate MgSO

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A. P. E.

M. A. N.

alpha

beta

gamma

Gamma X-ray Ultraviolet Infrared Microwave Radio

Increasing energy

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