General Chemistry I Exam 1

Dimensional Analysis

100

How many hydrogen atoms are in 135g of H₂O (molar mass = 18.015 g/mol)

9.02x10²⁴ atoms

200

what is the mass of 25.0 mL octane

 (density = 0.702 g/cm³)

1 cm³ = 1 mL

17.55 g

300

How many nanoliters are there in 3.57x10⁴ mg of CH3OH (density = 0.695 g/mL)

5.1x10^-8

400

The volume of a container holds 5.7 L of water. What is this volume in cm³?

1 inch = 2.54 cm

1 cm³ = 1 mL

347.6 cm³

500

A box has a volume of 4.75x10¹⁸ μm³. What is the volume of the box in cubic feet. 

2.54 cm = 1.00 inch

12 inches = 1.00 foot

168 ft³

Naming

100

calcium floride

CaF₂

200

CoN

cobalt (III) nitride 

300

name these polyatomic ions:

NO₂^-, SO₄^2-, and NH₄⁺

nitrite, sulfate, ammonium

400

(NH₄)₂PO4

ammonium phosphate

500

zinc (III) nitrate

Zn(NO₃)₃

Significant figures

100

How many sig figs?

0.000100

3

200

How many sig figs?

100,000.0

7

300

How many sig figs?

00204.0

4

400

What is the correct answer for the addition 102.5 mL + 6.55 mL

109.0 mL

500

What is the correct answer to the following mathematical operation expressed to the appropriate number of significant figures?

             .040

__________________

(2.6345x10^-4) x (7.91)

19

Unit Conversion

100

You are in Canada driving on the highway and the speed limit reads 120 km/hour. Your car is in miles/hour what is the speed limit in miles per hour?

1 km = 0.6214 miles

75 mi/hour

200

How many nanogram are in 5.27x10^-13

.527 nanogram

300

What is the mass of 2.4 x 10²³ molecules of NO₂ (molar mass = 46.0055 g/mol)

18 g

400

A loaf of bread has a mass of 24 ounces what is this in kg?

16 ounces = 453.6 g

.68 kg

500

A pump for a small swimming pool will circulate 3.77x10² gallons/hour through the filter. If the pool contains 6.85x10⁵ ounces of water, how many seconds will it take to filter the entire contents of the pool?

4.00 quarts = 1.00 gallon

1.00 quart = 32.0 ounces

5.11 x 10⁴ seconds. 

Balance Reactions

100

__CH4 + __O2 → __CO2 + __H2O 

44.0 g of CH4 are reacted with 39.5 g of O2 to form 14.3 g of H2O

Balance reaction and what is percent yield?

64.6%

200

__C2H6 + __O2 → __H2O + __CO2 

16.7 g of C2H6 are reacted with 29.2 g of O2 to form 19.9 g of CO2

Balance reaction and what is percent yield?

86.9%

300

__N2 + __H2 → __NH3 

9.30 g of N2 are reacted with 12.4 g of H2 to form 5.08 g of NH3

Balance reaction and what is percent yield?

45.0%

400

__Na + __H2O → __NaOH + __H2 

86.9 g of Na are reacted with 91.2 g of H2O to form 121 g of NaOH

Balance reaction and what is percent yield?

80.0%

500

__Sc2O3 + __SO3 → __Sc2(SO4)3 

18.6 g of Sc2O3 are reacted with 21.3 g of SO3 to form 29.0 g of Sc2(SO4)3

Balance reaction and what is percent yield?

86.3%