Practice Problems - West Linn-Wilsonville School District



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UNIT 2 STUDY GUIDE: Chapters 3-4

(Measurement, Metrics, Sig Figs, Dimensional Analysis)

Review Questions (Remember to use Significant Figures)

___ 1) In a slime-making experiment, a slime bag full of polyvinyl alcohol solution has a total mass of 45.600 grams. Some borax solution (mass of 8.500 g) is emptied into the slime bag. After the two ingredients react to make slime, you predict that the total mass of the slime and the bag will be:

[A] 45.600 g [B] 37.100 g [C] 54 g [D] 54.1 g [E] 54.100 g

___ 2) If a beaker has a mass of 0.265 kilograms, how many grams is this?

[A] 2.65 g [B] 0.00265 g [C] 265 g [D] 26 500 g [E] 265 000 g

___ 3) Write the following number in scientific notation : 0.00 000 001

[A] 108 [B] 10-8 [C] 107 [D] 10-7 [E] 10-9

___4) Which of the following are units of density?

[A] g/cm3 [B] g/mL [C] kg/L [D] All are units of density

___ 5) The slope of a straight-line graph is found by:

[A] rise divided by run [D] adding up each point

[B] run divided by rise [E] rise multiplied by run

[C] average values

___ 6) If the volume of an object with a mass of 188.57 g is 173 cm3, then its density is

[A] 1.086234 g/cm3 [B] 1.09 g/cm3 [C] 0.922688 g/cm3 [D] 0.92 g/cm3 [E] 1.00 g/cm3

___ 7) Will the above object float in fresh water which has a density of 1.00 g/cm3?

[A] yes [B] no [C] maybe [D] warm water only [E] extremely cold water only

Questions #8-9: You have been hired to test whether some silver-colored jewelry is pure silver, pure zinc, or silver mixed with zinc. The jewelry has a mass of 185 grams. You use a water displacement method to determine volume, by dropping the jewelry into a graduated cylinder which already contains some water. You then observe how much the water level rises.

The original volume of the water in the graduated cylinder is 40. cm3. After you add the jewelry, the new water level is 59 cm3.

___ 8) What is the volume of the jewelry ?

[A] 59 cm3 [B] 40 cm3 [C] 99 cm3 [D] 19 cm3 [E] 185 cm3

___ 9) What is the density of the jewelry?

[A] 9.7 g/cm3 [B] 0.103 g/cm3 [C] 3.1 g/cm3 [D] 2.1 g/cm3 [E] 5.2 g/cm3

10) List the number of significant figures in each number.

A) 567 B) 3.00 C) 1001 D) 1.0030 E) 1500.100

F) 0.00030 G) 0.0510 H) 50 I) 1234 J) 1.23x105

11) Perform each calculation using the proper number of significant figures.

A) 543 x 22.44 B) 66.11 + 77.0 C) 20.2 + 0.0087301

D) 0.000023 x 1030 E) 1.2x103 / 44 F) 66.321 - 10.00

12) Complete the following metric conversions:

A) 120.5 kg ( mg F) 88.35 mL ( L

B) 1.35 x 107 cm ( km G) 1772 g ( mg

C) 5.820 x 10-15 km ( cm H) 90046 g ( kg

D) 4.28 x 1010 L ( mL I) 0.00744 m ( cm

E) 15000. mg ( kg J) 2.890 x 10-6 km ( m

13) Complete the following conversions using dimensional analysis. SHOW YOUR WORK!

A) Convert 2.500 years into seconds. ANSWERS:

B) Convert 5.550 kg/L into g/mL.

C) Convert 20.55 g/L into kg/m3.

D) Convert 12.57 m/sec into miles/hr.

E) Convert 1.57 x 104 kg/m2 into lbs/ft2.

14) An experiment was performed to calculate the density of a rectangular solid. The solid had a mass of 25.66 g and had the following dimensions: 2.52 cm long, 7.358 cm wide, 0.885 cm tall. What is the density of the object?

15) If the accepted value for the density of solid object in the above problem is 1.590 g/mL, what is the % error in the experimentally obtained density?

16) Explain the difference between a qualitative and a quantitative measurement. Use an example to illustrate the difference.

17) The mass of a cube of iron is 355.0 g. IRON (Fe) has a density of 7.87 g/cm3.

A) What is the volume of this cube of iron?

B) The density of LEAD (Pb) is 11.4 g/cm3. What is the mass of a cube of lead with the same dimensions as the cube of iron?

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