# Stoichiometry: Watch Out—There's a Mole in This Quiz

Think you’ve got your head wrapped around Stoichiometry? Put your knowledge to the test. Good luck — the Stickman is counting on you!
Q. Consider the unbalanced equation Al + O2 → Al2O3. When this equation is correctly balanced (using the smallest whole numbers), what is the sum of the coefficients?

4
5
7
9
None of the above
Q. What is the molar mass of K2CO3?

138 g
106 g
99 g
67 g
None of the above
Q. What is the total number of atoms contained in 2.00 moles of Ni?

58.9
118
6.023 × 1023
1.2 × 1024
None of the above
Q. What is the percent by mass of oxygen in magnesium oxide, MgO?

20%
40%
50%
60%
None of the above
Q. A compound is 14% hydrogen and 86% carbon by mass. What is the formula of this compound?

CH
CH2
CH3
CH4
None of the above
Q. What is the mass in grams of 3.0x1023 molecules of CO2?

22 g
44 g
66 g
88 g
None of the above
Q. What is the molar mass of (NH4)3PO4?

113 g/mole
121 g/mole
149 g/mole
404 g/mole
None of the above
Q. Consider the following reaction: CH4 + 2 O2 → CO2 + 2 H2O. What amount of oxygen is needed to completely react with 1 mole of CH4?

2 moles
2 atoms
2 grams
2 molecules
None of the above
Q. How many oxygen atoms are represented by the formula Al2(CO3)3?

3
9
1
6
None of the above
Q. Three moles of Al2(CO3)3 contains how many moles of carbon atoms?

1
3
9
2
None of the above