WorksheetsUnit 6 Review
Total questions: 25
Worksheet time: 49mins
Name
Class
Date
1.
What is the SI unit for a count of atoms?
a)
meter
b)
mass
c)
molecule
d)
mole
2.
How many hydrogen atoms are in the compound: (NH4)2CO3
a)
3
b)
4
c)
6
d)
8
3.
What is the formula mass of CO2?
a)
44 grams
b)
44 amu
c)
0.44 grams
d)
2.6 x 1025 atoms
4.
What is the percent composition of nitrogen in NH3?
a)
25%
b)
14%
c)
28%
d)
82%
5.
Which of the following is an empirical formula?
a)
C3H3
b)
Li2CO3
c)
Na2O2
d)
C6H12O6
6.
How many moles are contained in 45 grams of aluminum?
a)
27 mol
b)
1215 mol
c)
1.7 mol
d)
57 mol
7.
How many moles of chlorine gas are contained in 45 grams of pure sample?
a)
35 mol
b)
0.64 mol
c)
1.3 mol
d)
2.6 mol
8.
How many atoms of are contained in a mole of sodium?
a)
6.02 x 1023 atoms
b)
11 atoms
c)
23 atoms
d)
2 atoms
9.
If the empirical formulas is CH and the molar mass is 78g/mol, what is the molecular formula?
a)
C6H6
b)
C5H18
c)
CH
d)
6CH
10.
How many moles are in 16.94g of water?
a)
16.94 mol H2O
b)
0.9401 mol H2O
c)
305.3 mol H2O
d)
1.063 mol H2O
11.
How many grams are in 1.2 x 1024 molecules of CO?
a)
28 grams
b)
56 grams
c)
6.02 grams
d)
1.2 grams
12.
A container with a volume of 893 L contains how many moles of air at STP?
a)
20003.2 L
b)
39.9 L
c)
22.4 L
d)
none of the choices
13.
What is the percent composition of Benzene, C6H6?
a)
C = 50%
H = 50%
H = 50%
b)
C = 85.7 %
H = 14.3%
H = 14.3%
c)
C = 92.2%
H = 7.8%
H = 7.8%
d)
C = 71.9%
H = 28.1%
H = 28.1%
14.
If 45.0 g of Mg react with 19.5 g of oxygen, what is the % of magnesium in the resulting compound?
a)
69.8%
b)
30.2%
c)
43.3%
d)
12.9%
15.
You are given the following percentages: 40.05% S and 59.95% O. Find the empirical formula for these elements. (keep two decimal places throughout calculations)
a)
SO
b)
SO2
c)
SO3
d)
SO4
16.
What is the molecular formula if the empirical formula is C2H5 and the molecular molar mass is 58.14 g/mol?
a)
C2H5
b)
C4H10
c)
C1H2.5
d)
C4H8
17.
Balance the following reaction :
CaC₂(s) + H₂O(l) --> C₂H₂(g) + Ca(OH)₂(aq)
CaC₂(s) + H₂O(l) --> C₂H₂(g) + Ca(OH)₂(aq)
a)
1,2,2,2
b)
1,2,1,1
c)
2,1,1,1
d)
2,1,2,1
18.
For the Balanced Reaction: 3 Mg + 1 Fe2O3 → 3 MgO + 2 Fe; What is the Ratio of moles of MgO to moles Fe?
a)
3mol Mg / 2 mol Fe
b)
2 mol Mg/ 3 mol Fe
c)
1 mol Fe/ 2 mol Fe
d)
3 mol MgO / 2 mol Fe
19.
2 NaClO3 (s) --> 2NaCl (s) +3 O2 (g)
1277.28 grams of NaClO3 will produce how many grams of O2?
a)
256 g of O2
b)
576 g of O2
c)
288 g O2
20.
2 CO (g) + O2(g) → 2 CO2 (g)
In the formation of CO2 from CO and oxygen, how many Liters of CO2 are produced by the reaction of 8 mols of O2 with an excess of carbon monoxide?
In the formation of CO2 from CO and oxygen, how many Liters of CO2 are produced by the reaction of 8 mols of O2 with an excess of carbon monoxide?
a)
0.178 L
b)
358.4 Liters
c)
704 grams
d)
0.36 grams
21.
What is the molar mass NaCl?
a)
58 grams
b)
22.95 grams
c)
162 grams
d)
6.02 x 1023
22.
How many atoms would be contained in 454 grams of iron?
a)
6.02 x 1023 atoms
b)
8.14 atoms
c)
4.89 x 1024 atoms
d)
55.9 x 1023 atoms
23.
If you want 1.55 moles of nitrogen trichloride, how many grams should you measure out?
a)
0.0129 g
b)
120. g
c)
187 g
d)
9.33 g
24.
What is the molar mass of Ca(NO3)2?
a)
148.096 g
b)
164.086 g
c)
102.055 g
d)
70.084 g
25.
What is the percent by mass of magnesium in MgO?
a)
20%
b)
40%
c)
50%
d)
60%
100 %
