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WorksheetsUnit 8 & 9 Chemistry
Total questions: 26
Worksheet time: 25mins
Name
Class
Date
1.
Consider separate 100.0 g samples of each of the following: NH3, N2O, HCN, N2H4, and HNO3. Which of the samples has the least mass of nitrogen?
a)
N2H4
b)
HNO3
c)
HCN
2.
In the reaction N2(g)+ 3H2(g) --> 2NH3(g), how many moles of ammonia would be produced from 1.0 mol of hydrogen and excess nitrogen?
a)
0.67 mol
b)
3.0 mol
c)
0.33 mol
3.
What is the molar mass of NaCl?
a)
58.44 g/mol
b)
175.3 g/mol
c)
2.00 g/mol
4.
What is the mass of 2.00 moles of Ca(OH)2
a)
122.5 g
b)
56 g
c)
148.2 g
5.
For the reaction C2H4(g) + 3O2(g) --> 2CO2(g) + 2H2O(g)if 6.0 mol of CO2 are produced, how many moles of O2 were reacted?
a)
15.0 mol
b)
4.0 mol
c)
9.0 mol
d)
7.5 mol
6.
A compound has a molar mass of 100 g/mol and the percent composition (by mass) of 65.45% C, 5.45% H, and 29.09% O. Determine the empirical formula and the molecular formula.
a)
CH4O and C3H12O3
b)
C3HO and C6H2O2
c)
C3H3O and C6H6O2
7.
Determine the percentage composition (by mass) of H2SO4.
a)
2.06% H, 32.69% S, 65.25% O
b)
33.33% H, 33.33% S, 33.33% O
c)
12.38% H, 44.93% S, 42.69% O
8.
Consider the equation 2A + 3B --> C. If 4.0 mol of A is reacted with 4.0 mol of B, which of the reactants is limiting?
a)
A is limiting because 2 is smaller than 3 (the numbers refer to the coefficients in the balanced equation).
b)
B is limiting because 3 is larger than 2 (the numbers refer to the coefficients in the balanced equation).
c)
B is limiting because 4.0 mol and 6.0 mol are needed.
9.
Determine the empirical formula of a compound containing 54.2% F and 45.8% S (by mass).
a)
SF
b)
SF2
c)
S2F2
d)
S2F
10.
Because atoms are so ______________, the standard units of mass are not useful in measurements.
a)
small
b)
scattered
c)
electrically charged
11.
How many molecules of O2 are there in 4.0 mol of O2?
a)
2.4 x 1024
b)
1.9 x 1025
c)
128
12.
How many moles of O2 are required for the complete reaction of 45 g of C2H4 to form CO2 and H2O?
a)
0.64 mol
b)
112.5 mol
c)
1.3 x 102 mol
d)
4.8 mol
13.
A 3.0-mol sample of KClO3 was decomposed according to the equation 2KClO3(s) --> 2KCl(s) + 3O2(g). How many moles of O2 are formed assuming 100% yield?
a)
2.0 mol
b)
3.0 mol
c)
4.5 mol
14.
The limiting reactant is the reactant
a)
that has the lowest coefficient in the balanced equation
b)
None of the above
c)
that is left over after the reaction has gone to completion
d)
for which you have the lowest mass in grams
15.
Which of the following has the highest mass percentage of nitrogen?
a)
HNO3
b)
N2H4
c)
HNO3
16.
Calculate the number of molecules in 0.000108 g of gaseous oxygen.
a)
2.03 x 10^18 molecules of oxygen
b)
6.02 x 10^23 molecules of oxygen
c)
1.33 x 10^21 molecules of oxygen
17.
For the reaction 2S(s) + 3O2(g) --> 2SO3(g), if 6.3 g of S is reacted with 10.0 g of O2, show by calculation which one will be the limiting reactant.
a)
Sulfur
b)
Oxygen
c)
Carbon
d)
Americium
18.
Which of the following has the highest mass percent of hydrogen?
a)
All have the same mass percent of hydrogen.
b)
CH4
c)
GeH4
19.
The molar mass of calcium hydroxide is
a)
29.8 g
b)
29.8 g
c)
74.1 g
20.
What mass of oxygen (O2) is required to react completely with 25.0 g of C6H14?
C6H14 + O2--> CO2 + H2O
C6H14 + O2--> CO2 + H2O
a)
88.2 g
b)
9.28 g
c)
608 g
21.
Calculate the mass of 3.50 mol of sulfur dioxide.
a)
4.1 x 1024 g
b)
224 g
c)
2.10 x 1024 g
22.
The mass percent of oxygen in CaO is
a)
28.5%
b)
cannot be determined from the information given
c)
50%
23.
The molar mass of blood sugar, C6H12O6, also known as glucose and dextrose, is
a)
29 g/mol
b)
180 g/mol
c)
6.02 x 1023 g/mol
d)
169 g/mol
24.
Calculate the mass of 20.0 moles of He (in g).
a)
80.1
b)
5.00
c)
1.20 x 1025
25.
The molar mass of calcium hydroxide is
a)
29.8 g
b)
57.6 g
c)
74.1 g
d)
1 g
26.
Who is the best Chemistry teacher at MHS?
a)
Ms. Carlson
b)
Not Ms. Carlson
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