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Practice Test 2
Chemistry 111
1) In the aqueous reaction of K2SO4 (aq) + Ba(NO3)2 (aq) → BaSO4 (s) + 2KNO3 (aq), which
ions are the spectator ions?
Ba2+ and SO42Ba2+ and K+
Ba2+ and NO3K+ and SO42K+ and NO3-
A)
B)
C)
D)
E)
2)
Which of the following choices represents the net reaction which actually takes place
in solution when the strong acid HCl (aq) is added to Ba(OH)2 (aq)?
A)
HCl(aq) + Ba(OH)2(aq) → BaCl2(aq) + H2O(l)
B)
H+ + OH → H2O(l)
C)
HCl(aq) + OH- → Cl + H2O(l)
D)
H
E)
HCl(aq) + Ba
-
-
+
+ Ba(OH)2(aq) → Ba2+ + H2O(l)
2+
→ BaCl2(aq) + H+
3)
Vinegar contains a weak acid, acetic acid (HC2H3O2), which is responsible for its
acidity. In one analysis of a commercial vinegar brand, a 15.0 mL sample was titrated with
0.4500 M NaOH. It required 30.50 mL of this NaOH solution to neutralize the acid in the
vinegar sample. What is the molar concentration of acetic acid in vinegar?
A)
B)
C)
D)
E)
0.102 M
0.221 M
0.305 M
0.458 M
0.915 M
4)
The volume of 0.200 M K2CO3 solution that contains 69.0 g of K2CO3 is:
A)
B)
C)
D)
E)
0.400 L
200 mL
1.60 L
500 mL
2.50 L
5)
Given the following unbalanced reaction:
V2O5 + C + Cl2 → VOCl3 + COCl2
When properly balanced, the equation shows that for every one mole of VOCl3 formed
______________ mole(s) of carbon are required.
A)
B)
C)
D)
E)
6)
1
3/2
2
5/2
3
Which of the following compounds should be insoluble in water?
A) AgNO3
B) Na2CO3
C) PbS
D) Na2S
E) NH4Cl
7)
The correct complete ionic equation for the reaction that occurs when aqueous
solutions of Ca(NO3)2 and Na2CO3 are mixed is
A) Ca(NO3)2(aq) + Na2CO3(aq) ----> CaCO3(s) + 2 NaNO3(aq)
B) Ca2+(aq) + 2 NO3-(aq) + 2 Na+(aq) + CO32-(aq) ----> CaCO3(s) + 2 Na+(aq) + 2 NO3-(aq)
C) Ca2+(aq) + 2 NO3-(aq) + 2 Na+(aq) + CO32-(aq) ----> Ca2+(aq) + CO32-(aq) + 2 NaNO3(s)
D) Ca2+(aq) + CO32-(aq) ----> CaCO3(s)
E) Na+(aq) + NO3-(aq) ----> NaNO3(s)
8)
Which of the following is a neutralization reaction?
A) HCl(aq) + AgNO3(aq) ----> AgCl(s) + HNO3 (aq)
B) CuSO4(aq) + Zn(s) ----> ZnSO4(aq) + Cu(s)
C) 2 K(s) + 2 H2O(l) ----> 2 KOH(aq) + H2(g)
D) H2SO4(aq) + 2 NaOH(aq) ----> 2 H2O(l) + Na2SO4(aq)
E) None of the above.
9)
What is the oxidation number of Cr in K2Cr2O7?
A) +12
B) +3
C) +4
D) +5
E) +6
10)
In which of the following reactions does an oxidation-reduction process occur?
A) HCl(aq) + AgNO3(aq) ----> AgCl(s) + HNO3 (aq)
B) CuSO4(aq) + Zn(s) ----> ZnSO4(aq) + Cu(s)
C) 2 K(s) + 2 H2O(l) ----> 2 KOH(aq) + H2(g)
D) 2 HCl(aq) + Ca(OH)2(aq) ----> 2 H2O(l) + CaCl2(aq)
E) B and C
11) What volume of 3.0 M NaOH can be prepared using exactly 96.0 g of NaOH?
(MM NaOH = 40.0 g/mol)
A) 0.14 L
B) 0.70 L
C) 0.80 L
D) 1.25 L
E) 7.20 L
12)
What volume of water must be added to 300 mL of 0.75 M HCl to dilute the
solution to 0.25 M?
A) 900 mL
B) 600 mL
C) 300 mL
D) 930 mL
E) 100 mL
13)
The limiting reagent is the substance:
A) present in greatest quantity
B) limits the number of reagents present
C) determined by the amount of reactants present
D) that determines the maximum amount of possible product
14)
Write the overall molecular equation and the net ionic equation when the following
aqueous reagents are mixed:
A)
silver (I) chlorate is added to sodium chromate
B)
C)
16)
Nitrous acid, a weak acid with the formula HNO2, reacts with Ca(OH)2
Hydrobromic acid reacts with potassium hydroxide
Please show all of your work on this problem to receive full credit.
Hydrochloric acid can be prepared by the following (unbalanced) reaction:
NaCl(s) +
A)
B)
C)
H2SO4(aq)

HCl(g) +
Na2SO4(aq)
How many grams of HCl can be prepared from 3.00 mol H2SO4 and 140 g NaCl?
At the end of the reaction, how much of each reactant remains?
If the reaction yield is really only 75%, how much HCl will actually be prepared?
1. Which of the following is true for a gas at STP?
a. 0 atm
b. 0 °C
c. 25 °C
d. 25 atm
2.
Which of the following reactions is likely exothermic?
a. decomposition of carbon dioxide
b. formation of hydrogen bromide
c. formation of propane
d. b and c
3. What does ΔH° = -98.3 kJ/mol for
CH4 (g) +
Cl2 (g) →
CH3Cl (g)
+
HCl
tell us about the reaction?
a. The reaction is product-favored at room temperature
b. The reaction is exothermic
c. The reaction is endothermic
d. a and b
(g)
4. If the
a.
b.
c.
d.
reaction above is reversed and uses 3.3 moles HCl, what is ΔH?
+98.3 kJ
-324.4 kJ
+324.4 kJ
-98.3 kJ
5. What
a.
b.
c.
d.
is ΔH for the reaction in #4 for 25.0 g of methane?
+163.4 kJ
-163.4 kJ
+2457.5 kJ
+2457.5 kJ
6. What
a.
b.
c.
d.
happens when dry ice (carbon dioxide) sublimates?
Energy is released.
Energy is absorbed.
Need more information.
Neither a or b.
7. If 2.5L of gas at 99843 Pa is reduced to a volume of 1.5, what is the new
pressure in atm? (5 pts)
8. Calculate the enthalpy change (kJ/mol) for the formation of one mole of
carbon monixide according to this reaction: (10 pts)
C
(s)
+
H2O
CO (g) +
(g) →
H2 (g)
using the following information:
C (s) +
2 CO (g)
2 H2 (g)+
O2 (g) →
+
O2
O2 (g)
CO2
ΔH°
-393.5 kJ
-566.0 kJ
-483.6 kJ
(s)
(g)
→
→
2 CO2
2 H2O (g)
(g)
You must use the information above for credit on this question.
14. Consider the following unbalanced reaction:
Fe
(s)
+ HCl
(aq)
→
FeCl2
(aq)
+
H2
(g)
What volume (in liters) of hydrogen gas at STP is released by mixing 5.34 g of iron
with 5.00 mL of 1.250 M HCl? (15 pts)
15. Calculate ΔH° in kJ/mol for the combustion of acetylene, C2H2, using standard
heats of formation. Assume that any water formed will be a vapor. (10 pts)