Sample Problem for Stoichiometry, General Chemistry

1. STOICHIOMETRY
by A.J. Herrera

2. QUESTION 1
What is the coefficient of carbon dioxide when the if
Equation when isopropyl alcohol was combusted is
balanced with the smallest whole number coefficient?
C3H80 + 02 CO2 + H2O
Answer:
3
by A.J. Herrera

3. QUESTION 2
Determine the number of sulfur atoms in 27.1 g of
molecular sulfur.
Answer:
5.09x10^23
by A.J. Herrera

4. QUESTION 3
What is the formula weight of Ca3(PO4)2 ?
Answer:
310 amu
by A.J. Herrera

5. QUESTION 4
Calculate the percent by mass of nitrogen in ammonium
nitrate (NH4NO3)
Answer:
35.0%
by A.J. Herrera

6. QUESTION 5
A 4.628 g sample of an oxide of iron was found that
contains 3.35 g of iron and 1.280 g of O. What is the
simplest formula for this compound?
Answer:
Fe3O4
by A.J. Herrera

7. QUESTION 7
How many moles of O2 are required to react with 23.5
moles of Methanol.
2CH3OH + 3O2 2C02 + 4H20
ANSWER:
35.25 moles of O
by A.J. Herrera

8. QUESTION 8
A compound contains by mass 87.5% of Nitrogen and
12.5% hydrogen. It’s molecular weight was found to
be 32 g/mol. What is the molecular Formula?
ANSWER:
N2H4
by A.J. Herrera

9. QUESTION 9
If 58 moles of NH3 are combined with 32 moles of
Sulfuric Acid, what is the limiting reactant and how
much of the excess reactant is left over?
2 NH3 + H2SO4 (NH4)2 SO4
ANSWER:
NH3 and 3 mol
by A.J. Herrera

10. QUESTION 10
What is the percent yield of CO2 if the reaction of the
CO with excess O2 produced 12.8 g of CO2?
ANSWER:
78.1%
by A.J. Herrera