Quizes :  Stoichiometry
1. The molecular formula of a compound is represented by X3Y6. What is the empirical formula of this compound?
a) X3Y
b) X2Y
c) XY2
d) XY3

2. What is the total number of moles of sulfur atoms in 1 mole of Fe2(SO4)3?
a) 1
b) 15
c) 3
d) 17

3. Which sample contains a total of 6.0 x 1023 atoms?
a) 23 g Na
b) 24 g Ca
c) 42 g Kr
d) 78 g K

4. A 20.-milliliter sample of 0.60 M HCl is diluted with water to a volume of 40. milliliters. What is the new concentration of the solution?
a) 0.15 M
b) 0.60 M
c) 0.30 M
d) 1.2 M

5. Given the reaction:

4 Al(s) + 3 O2(g) 2 Al2O3(s)

What is the minimum number of grams of oxygen gas required to produce 1.00 mole of aluminum oxide?
a) 32.0 g
b) 48.0 g
c) 96.0 g
d) 192 g

6. What is the mass of 1 mole of a gas that has a density of 2.00 grams per liter at STP?
a) 11.2 g
b) 22.4 g
c) 33.6 g
d) 44.8 g

7. A compound was analyzed and found to contain 75% carbon and 25% hydrogen by mass. What is the compounds empirical formula?
a) CH
b) CH2
c) CH3
d) CH4

8. What is the molar mass of Ca(OH)2?
a) 29 g
b) 34 g
c) 57 g
d) 74 g

9. What is the empirical formula for C3H6?
a) CH
b) CH2
c) CH3
d) CH6

10. What is the percent by mass of carbon in CO2?
a) 12
b) 27
c) 44
d) 73

11. Given the reaction:

N2(g) + 3 H2(g) 2 NH3(g)

What is the total number of moles of NH3(g) produced when 10. moles of H2(g) reacts completely with N2(g)?
a) 6.7
b) 2.0
c) 3.0
d) 1.5

12. The volume occupied by 9.03 x 1023 molecules of N2 gas at STP is closest to
a) 0.500 liter
b) 1.50 liters
c) 22.4 liters
d) 33.6 liters

13. What is the total number of moles of atoms represented by the formula Al(C2H3O2)3?
a) 22
b) 11
c) 8
d) 4

14. Given the reaction:

C3H8(g) + 5 O2(g) 4 H2O(g) + 3 CO2(g)

What is the total number of liters of H2O(g) produced when 1.0 liter of C3H8(g) reacts completely with 7.5 liters of O2(g)?
a) 1.0
b) 5.0
c) 3.0
d) 4.0

15. Which substance has the greatest molecular mass?
a) H2O2
b) NO
c) CF4
d) I2

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