1. )Balance the following equation. What is the sum of the coefficients of the reactants?
C6H10O5 + ____ O2 — ____ CO2 + ____ H2O
a) 7
b) 11
c) 3
d) 6
e) 18
2.) Phosphorus is prepared commercially by the following method. Balance the equation. What is the coefficient
of CO in the balanced equation?
____ Ca3(PO4)2 + ____ SiO2 + ____ C –
____ P4 + ____ CaSiO3 + ____ CO
a) 2
b) 6
c) 4
d) 12
e) 10
3.) Which statement is false for the balanced equation given below?
(Atomic weights: N = 14.01, O = 16.00).
N2 + O2 — 2 NO
a) The reaction of 14.0 g of N2 will produce 30 g of NO
b) The reaction of one mole of O2 will produce 60 g of NO
c) Ten molecules of N2 will produce twenty molecules of NO
d) The reaction of 32.0 g of O2 will produce 30 g of NO
e) One mole of N2 will produce 2 moles of NO
4.) Which of the following setups is correct to calculate the mass of oxygen produced from 0.25 moles of KClO3
according to the following equation?
(Atomic weights: K = 39.1, Cl = 35.45, O = 16.00)
2 KClO3 — 2 KCl + 3 O2
a) 0.25 moles KClO3 x 3 moles O2/2 moles KClO3 x 1 mole O2/32 g
b) 0.25 moles KClO3 x 3 moles O2/2 moles KClO3 x 32 g/1 mole O2
c) 0.25 moles KClO3 x 2 moles KClO3/3 moles O2 x 32 g/1 mole O2
d) 0.25 moles KClO3 x 2 moles KClO3/3 moles O2 x 1 mole O2/32 g
5.) How many moles of potassium chlorate may be produced from 2.4 moles of chlorine assuming that sufficient potassium hydroxide is available.
3 Cl2 + 6 KOH — 5 KCl + KClO3 + 3 H2O
a) 7.2
b) 1.20
c) 0.20
d) 0.80
e) 0.40
6.) How many grams of carbon is required to produce 0.460 moles of SiC?
(Atomic weights: C = 12.0, Si = 28.09, O = 16.00).
SiO2 + 3 C — SiC + 2 CO
a) 17.2
b) 16.6
c) 17.8
d) 15.4
e) 16.0
7.) How many grams of HCl are produced from 1.23 g TiCl4 according to the following reaction?
(Atomic weights: Ti = 47.90, Cl = 35.45, H = 1.008).
TiCl4 + 2 H2O — TiO2 + 4 HCl
a) 0.472
b) 0.624
c) 0.946
d) 0.388
e) 0.812
8.) The equation for the reduction of iron ore in a blast furnace is given below. How many kilograms of iron can
be produced by the reaction of 7.00 kg of Fe2O3 and 3.00 kg of CO?
(Atomic weights: Fe = 55.85, O = 16.00, C = 12.01).
Fe2O3 + 3 CO — 2 Fe + 3 CO2
a) 3.99
b) 4.32
c) 3.65
d) 4.74
e) 4.20
9.) The reaction of 37.0 g C6H12O in the presence of acid yields 25.0 C6H10. What is the percent yield of the
reaction?
C6H12O — C6H10 + H2O
a) 76.2
b) 79.2
c) 82.4
d) 78.1
e) 83.2
10.) The mass of H2 produced by reaction of 1.80 g Al and 6.00 g H2SO4 is 0.112 g. What is the percent yield?
(Atomic weights: Al = 26.98, S = 32.06, O = 16.00, H = 1.008).
2 Al + 3 H2SO4 — Al2(SO4)3 + 3 H2
a) 90.8
b) 94.5
c) 92.4
d) 93.0
e) 93.4
11.) Metal carbonyls are molecular compounds. Assume that you heat and decompose completely 1.322 g of
Fex(CO)y to form 0.377 g of iron. What is the empirical formula of the compound?
(Atomic weights: Fe = 55.85, C = 12.01, O = 16.00).
a) Fe2(CO)5
b) Fe(CO)6
c) Fe2(CO)3
d) Fe(CO)4
e) Fe(CO)5
12.) Determine the empirical formula of Kelvar, used in making bullet proof vests, is 70.6% C, 4.2% H, 11.8% N
and 13.4% O.
(Atomic weights: C = 12.01, H = 1.008, N = 14.01, O = 16.00).
a) C7H5NO2
b) C7H5N2O
c) C7H5NO
d) C7H9NO2
e) C7H9NO
13.) A semiconductor consists of 47.6% silver and 52.4% tin What is the empirical formula?
(Atomic weights: Ag = 107.9, Sn = 118.7).
a) AgSn
b) Ag3Sn2
c) AgSn2
d) Ag2Sn
e) Ag2Sn3
14.) The mineral fayalite contains 54.8% Fe, 13.8% Si and 31.4% O. What is the empirical formula?
(Atomic weights: Si = 28.1, Fe = 55.8, O = 16.00).
a) Fe2SiO4
b) FeSiO3
c) FeSiO2
d) FeSiO
e) Fe2SiO2
15.) When 0.880 g of an organic compound containing carbon, hydrogen and oxygen is burned completely in
oxygen, 1.760 g of CO2 and 0.720 g H2O are produced. What is the empirical formula of the compound?
(Atomic weights: carbon = 12.01, H = 1.008, O = 16.00).
a) C3H6O2
b) C3H6O4
c) C2H2O
d) C2H4O
e) CHO
16.) Aziridine contains only carbon, hydrogen and nitrogen. When a 0.4622 g sample is burned completely in
oxygen, 0.9673 g of CO2 and 0.3960 g of H2O are formed. What is the empirical formula?
(Atomic weights: C = 12.01, H = 1.008, O = 16.00, N = 14.01).
a) C2H4N
b) C2H3N
c) C2H4N3
d) C3H6N
e) CHN
17.) A 6.156 mg sample of a compound containing carbon, hydrogen, oxygen and nitrogen was burned to produce
13.20 mg CO2 and 2.252 mg H2O. In a separate reaction, 0.735 mg of the substance was converted into 0.154 mg
of NH3. What is the empirical formula of the compound?
(Atomic weights: C = 16.00, H = 1.008, O = 16.00, N = 14.01).
a) C6H5NO
b) CHNO2
c) C3H4N2O
d) C6H5NO
e) C2H2NO
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