Exam
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) There are __________ sulfur atoms in 25 molecules of C4 H4 S2 .
1)
A) 3.0 × 1025
B) 50
C) 4.8 × 1025
D) 1.5 × 1025
E) 6.02 × 1023
2) How many grams of hydrogen are in 46 g of CH4 O?
A) 0.36
B) 5.8
C) 184
2)
D) 1.5
E) 2.8
3) How many moles of carbon dioxide are there in 52.06 g of carbon dioxide?
3)
A) 1.183
B) 3.134 × 1025
C) 8.648 × 1023
D) 6.022 × 1023
E) 0.8452
4) There are __________ molecules of methane in 0.123 mol of methane (CH4 ).
4)
A) 2.46 × 10-2
B) 2.04 × 10-25
C) 5
D) 7.40 × 1022
E) 0.615
5) A 2.25-g sample of magnesium nitrate, Mg(NO3 )2 , contains __________ mol of this compound.
A) 0.0261
B) 38.4
C) 65.8
D) 148.3
E) 0.0152
6) What is the empirical formula of a compound that contains 29% Na, 41% S, and 30% O by mass?
A) Na2 S2 O6
B) NaSO2
C) NaSO
1
D) NaSO3
5)
E) Na2 S2 O3
6)
7) Magnesium and nitrogen react in a combination reaction to produce magnesium nitride:
3 Mg + N2
7)
Mg3 N2
In a particular experiment, a 9.27-g sample of N2 reacts completely. The mass of Mg consumed is
__________ g.
A) 13.9
B) 16.1
C) 0.92
D) 24.1
E) 8.04
8) The combustion of ammonia in the presence of excess oxygen yields NO2 and H2 O:
4 NH3 (g) + 7 O2 (g)
8)
4 NO2 (g) + 6 H2 O (g)
The combustion of 28.8 g of ammonia consumes __________ g of oxygen.
A) 108
B) 28.8
C) 54.1
D) 94.9
E) 15.3
9) The combustion of propane (C3 H8 ) in the presence of excess oxygen yields CO2 and H2 O:
C3 H8 (g) + 5O2 (g)
9)
3CO2 (g) + 4H2 O (g)
When 2.5 mol of O2 are consumed in their reaction, __________ mol of CO2 are produced.
A) 6.0
B) 2.5
C) 1.5
D) 3.0
E) 5.0
10) Lead (II) carbonate decomposes to give lead (II) oxide and carbon dioxide:
PbCO3 (s)
10)
PbO (s) + CO2 (g)
How many grams of lead (II) oxide will be produced by the decomposition of 2.50 g of lead (II)
carbonate?
A) 0.41
B) 2.09
C) 0.00936
D) 2.61
E) 2.50
11) GeF3 H is formed from GeH4 and GeF4 in the combination reaction:
GeH4 + 3GeF4
11)
4GeF3 H
If the reaction yield is 92.6%, how many moles of GeF4 are needed to produce 8.00 mol of GeF3 H?
A) 5.56
B) 6.48
C) 2.16
D) 2.78
E) 3.24
12) Silver nitrate and aluminum chloride react with each other by exchanging anions:
3AgNO3 (aq)+ AlCl3 (aq)
12)
Al(NO3 )3 (aq) + 3AgCl (s)
What mass in grams of AgCl is produced when 4.22 g of AgNO3 react with 7.73 g of AlCl3 ?
A) 24.9
B) 3.56
C) 4.22
D) 17.6
2
E) 11.9