GENERAL CHEMISTRY
Calculations Based on Equations
Sheet No. 3
1. How many grams of O, Cl, Ca, Al, Br, react with 1 gram of hydrogen?
2. Calculate the weight of CaO that can be prepared by heating 200g of CaCO 3 according to
CaCO3
CaO + CO2.
3. Calculate the weight of CaO that can be prepared by heating 200g of 95% pure CaCO 3 according to
CaCO3
CaO + CO2 .
4. C7H14(l)
C7H8(l) + H2(g)
C7H14 and C7H8 are liquids. Hydrogen is a gas. What is the % loss of wt. in the above reaction?
5. Given: C5H11OH + O2
CO2 + H2O
A. How many moles of O2 are needed for the combustion of 1 mole of alcohol?
B. How many moles of H2O are formed for each mole of O2 consumed?
C. How many grams of CO2 are produced for each mole of alcohol burned?
6. How many grams of H2SO4 could be obtained from 1000g of FeS2 according to:
FeS2 + O2
SO2 + O2
SO3 + H2O
Fe2O3 + SO2
SO3
H2SO4
7. Derive the empirical (simple) formula of each of the following:
A.
Fe 63.53% S 36.46%
B.
Fe 46.55% S 53.45%
8. A compound contains 21.6% Na, 33.3% Cl and 45.1% O 2. Derive the simple formula for the
compound.
9. A compound contains 19.3% Na, 26.9% S, and 53.8% O. The molecular weight of the compound is
238. Derive:
A.
the simple formula
B.
the molecular formula
10. 50 lb. of KClO3 were decomposed. How many lbs. of KCl were formed?
ANSWERS
Calculations Based on Equations
Sheet No. 3
1.
8 g of O
35.5 g of Cl
20 g of Ca
9 g of Al
80 g of Br
2.
112 g
3.
106.4
4.
6.12%
5.
(a) 7.5 mols of oxygen
6.
1636 g
7.
(a) FeS
8.
NaClO3
9.
(a) NaSO4
10.
30.4 lbs.
(b) .8 mols of H2O
(b) FeS2
(b) Na2S2O8
(c) 220 g CO2