What is the molar mass of AuCl3?
a. 96 g c. 232.5 g
b. 130 g d. 303.6 g
D. 303.6 g
100
Which combination of temperature and pressure correctly describes standard temperature and pressure, STP?
a. 0 C and 101 kPa c. 0 C and 22.4 kPa
b. 1 C and 0 kPa d. 100 C and 100 kPa
A. 0 c and 101 kPa
100
Given 1.00 mole of each of the following gases at STP, which gas would have the greatest volume?
a. He c. SO3
b. O2 d. All would have the same volume.
D. All would have the same volume
100
Which expression represents the percent by mass of nitrogen in NH4NO3?
a. 14 g N/80 g NH4NO3 x 100%
b. 28 g N/80 g NH4NO3 x 100%
c. 80 g NH4NO3 /14 g N x 100%
d. 80 g NH4NO3 /28 g N x 100%
B. 28 g N/80 g NH4NO3 x 100%
100
Which of the following is NOT true about empirical and molecular formulas?
a. The molecular formula of a compound can be the same as its empirical formula.
b. The molecular formula of a compound can be some whole-number multiple of its empirical formula.
c. Several compounds can have the same empirical formula, but have different molecular formulas.
d. The empirical formula of a compound can be triple its molecular formula.
D. The empirical formula of a compound can be triple its molecular formula.
200
What is the molar mass of (NH4)2CO3?
a. 144 g c. 96 g
b. 138 g d. 78 g
C. 96 g
200
If 60.2 grams of Hg combines completely with 24.0 grams of Br to form a compound, what is the percent composition of Hg in the compound?
a. 28.5% c. 71.5%
b. 39.9% d. 60.1%
C. 71.5%
200
Which of the following compounds has the lowest percent gold content by weight?
a. AuOH c. AuCl3
b. Au(OH)3 d. AuI3
D. AuI3
200
Which of the following sets of empirical formula, molar mass, and molecular formula is correct?
a. CH, 78 g, C13H13
b. CH4N, 90 g, C3H12N3
c. CaO, 56 g, Ca2O2
d. C3H8O, 120 g, C3H8O2
B. CH4N, 90 g, C3H12N3
300
What is the number of moles in 432 g Ba(NO3)2 ?
a. 0.237 mol c. 1.65 mol
b. 0.605 mol d. 3.66 mol
C. 1.65 mol
300
What is the number of moles in 9.63 L of H S gas at STP?
a. 0.104 mol c. 3.54 mol
b. 0.430 mol d. 14.7 mol
B. 0.430 mol
300
If 20.0 grams of Ca combines completely with 16.0 grams of S to form a compound, what is the percent composition of Ca in the compound?
a. 1.25% c. 44.4%
b. 20.0% d. 55.6%
D. 55.6%
300
Which of the following compounds has the highest oxygen content, by weight?
a. Na2O c. BaO
b. CO2 d. H2O
D. H2O
300
Everyday equations describe ____.
a. thermonuclear reactions c. chemical reactions
b. everyday processes d. biological chemistry
B. everyday processes
400
How many moles of CaBr2 are in 5.0 grams of CaBr2?
a. 2.5 x 10^-2 mol c. 4.0 x 10^1 mol
b. 4.2 x 10^-2 mol d. 1.0 x 10^3 mol
A. 2.5 x 10^-2 mol
400
The molar mass of a certain gas is 49 g. What is the density of the gas in g/L at STP?
a. 3.6 10 g/L c. 2.2 g/L
b. 0.46 g/L d. 71 g/L
C. 2.2 g/L
400
What is the percent composition of carbon, in heptane, C7H16?
a. 12% c. 68%
b. 19% d. 84%
D. 84%
400
Which of the following compounds have the same empirical formula?
a. CO2 and SO2
b. C7H14 and C10H20
c. C4H10 and C10H4
d. C6H12 and C6H14
B. C7H14 and C10H20
400
Chemical equations ____.
a. describe chemical reactions
b. show how to write chemical formulas
c. give directions for naming chemical compounds
d. describe only biological changes
A. describe chemical reactions
500
What is the mass of oxygen in 250 g of sulfuric acid, H2SO4?
a. 0.65 g c. 16 g
b. 3.9 g d. 160 g
D. 160 g
500
Which of the following gas samples would have the largest number of representative particles at STP?
a. 12.0 L He c. 0.10 L Xe
b. 7.0 L O2 d. 0.007 L SO3
A. 12.0 L He
500
What is the percent by mass of carbon in acetone, C3H6O?
a. 20.7% c. 1.61%
b. 62.1% d. 30.0%
B. 62.1%
500
What is the empirical formula of a substance that is 53.5% C, 15.5% H, and 31.1% N by weight?
a. C3HN2
b. C4H14N2
c. C2H8N
d. CH4N7
C. C2H8N
500
Symbols used in equations, together with the explanations of the symbols, are shown below. Which set is correct?
a. (g), grams c. (aq), dissolved in water
b. (l), liters d. (s), solid product