PRINCE GEORGE’S COMMUNITY COLLEGE
CHM1010 (SHAH)
REVIEW (CHAPTERS 4 TO 6)
CHAPTER 4:
1. How much CO2 can be produced by burning 3.5 x 1015g of butane (C8H18)?
(Answer: 1.1 x 1016g CO2)
2. What mass of HCl is required to neutralize 3.26g of Mg(OH) 2?
Mg(OH) 2 + 2HCl  MgCl2 + 2H2O
(answer: 4.08g)
3. What mass of glucose can be synthesized from 37.8g of CO2 in the following reaction?
Assuming that there is more than enough water present to react with all CO 2. (25.8g)
6CO2(g) + 6 H2O(l)  6O2 (g) + C6H12O6 (aq)
4. Write molecular, ionic, and net ionic reactions: (Hint: First write the products and
balance it)
a. Reaction between: Pb(NO3)2 and (NH4) 2SO4
b. Reaction between: NaNO3 and BaCl2
c. Reaction between: NaOH and SnCl2
d. Reaction between: HNO3 and Ca(OH)2
5. Write ionic equation and net ionic equations for the following reactions.
a. 2AgNO3(aq) + Na2CrO4 (aq)  Ag2CrO4(s) + 2NaNO3(aq)
b. H2SO4(aq) + MgCO3(s)  H2O(l) + CO2 (g) + MgSO4(aq)
c. Hg2 (NO3) 2(aq) + 2NH4Cl(aq)  Hg2Cl2(s) + 2NH4NO3(aq)
6. If 42.5g of Mg reacts with 33.8g of O2 as follow:
2Mg(s) + O2(g)  2MgO(s)
a. Which one is a limiting reactant?
b. What is the theoretical yield of MgO?
c. If experimental yield of MgO is 55.9g, what is the % yield?
(answer: Mg is a limiting reactant, theoretical yield is 70.5g, and % yield is 79.3%)
7. Ammonia can be synthesized by the following reaction:
3H2 (g) + N2 (g)  2NH3(g)
If 5.22 kg of H2 reacts with 31.5kg of N2:
a. Which one is a limiting reactant?
b. What is the theoretical yield of ammonia?
c. If the experimental yield of NH3 is 28.3kg, what is the % yield?
(answer:H2 is a limiting reactant, 29.4kg of NH3 is the theoretical yield, and 96.3%
yield)
8. If 25.5g of KBr is dissolved in enough water to make 1.75L of solution, what is the
molarity of the solution? (answer: 0.122M)
9. If 45.4g of NaNO3 is dissolved in enough water to make 2.50L of solution, what is the
molarity of the solution? (answer:0.214M)
10. If 5.5g of NaCl is dissolved in enough water to make 1.25L of solution, what is the
molarity of the solution? (answer: 0.075M)
11. What mass of KBr do you need to make 250.0mL of a 1.50M KBr solution?
(answer: 44.6g KBr)
12. If we dissolve 25grams of salt in 251g of water, what is the mass of the solution?
13. How many liters of a 0.125M NaOH solution contains 0.255mol of NaOH? (2.04L)
14. How many grams of sucrose (C12H22O11) are in 1.55L of 0.75M sucrose solution?
(answer: 402g)
15. How many mL of a 0.155M KCl solution contains 2.55g KCl? (221mL KCl)
16. To what volume should you dilute 0.200L of a 15.0M NaOH solution to obtain a 3.00M
NaOH solution? (answer: 1.00L)
17. To what volume should you dilute 100.0mL of a 5.00M CaCi2 solution to obtain a
0.750MCaCl2 solution? (answer: 667mL)
18. What volume of a 6.00M NaNO3 solution should you use to make 0.525L of a 1.20M
NaNO3 solution? (answer: 0.105L)
19. What volume in liter of 0.150M KCl solution will completely react with 0.150L of a
Pb(NO3)2 solution according the following chemical reaction:
2KCl(aq) + Pb(NO3) 2(aq)  PbCl2 (s) + 2KNO3 (aq)
(answer: 0.350L KCl solution)
20. Identify the following compounds as strong, weak, or nonelectrolyte:
a. A sugar solution
b. Vinegar
c. A salt solution
d. NaOH solution
e. Aqueous ammonia
f. 0.1M HCl solution
21. Write whether the following compounds are soluble, slightly soluble or insoluble in
water: (Hint: use solubility rules)
a. AgCl
AgNO3
CH3COONa
b. BaSO4
SrSO4
Ca(OH) 2
c. CaS
CaCO3
(NH4) 2CO3
Chapter: 5 Gases
Key formulas or conversion factors:
1 atm = 760mmHg = 760 torr
1mmHg = 1 torr
1 Pa = 1N/m2 = 1kg/m.s2 (SI unit for pressure is Pascal (Pa), P = F/A = m.a/A,
SI unit for force is newton (N) 1N =1kg.m/s2
1 atm = 101,325Pa= 101.325 kPa
1 atm = 29.92 in Hg (inches of mercury)
1 atm = 14.7 psi
P1V1 = P2V2 (Boyle’s law)
V1/T1 = V2/T2 (Charles’s law)
V1/n1 = V2/n2 (Avogadro’s law)
P1V1/T1 = P2V2/T2 (Combined gas law)
PV = nRT (Ideal gas law)
R = 0.08206 L.atm/mol.K (Ideal gas constant)
Standard temperature and pressure (STP): 1 atm and 0°C (273.15K)
Molar volume of a gas at STP is 22.4L
(Volume of 1 mol of a gas = 22.4L at STP)
Density (d) = PM/RT
Ptotal = P1 + P2+ P3 …. (Dalton’s law) for mixtures of gases
R1/R2 = (M2/M1)½ (Graham’s law of effusion) at constant temperature and pressure
22. A high performance road bicycle tire is inflated to a total pressure of 132psi. What is this
pressure in mmHg? (6.82 x 103mmHg)
23. If barometric pressure is 30.44 inHg, what is this pressure in psi? (15.0 psi)
24. A cylinder equipped with a movable piston has a volume of 7.25L under an applied
pressure of 4.52atm. What is the volume of cylinder if we decrease the applied pressure
to 1.21 atm? (27.1L)
25. A sample of gas has a volume of 2.80L at an unknown temperature. When the sample is
submerged in ice water at t = 0.00° C, its volume decreases to 2.57L. What was the
initial temperature in K? (answer: 297.6K)
26. A gas in a gas cylinder with a movable piston has an initial volume of 88.2mL. If we heat
the gas from 35°C to 155°C, what is the final volume in mL? (answer: 123mL)
27. 4.65L sample of He gas contains 0.225 mol of He. How many additional moles of He gas
must we add to the sample to obtain a volume of 6.48L? Assume constant temperature
and pressure. (0.089 mol)
28. Calculate the volume occupied by 0.845mol of N2 gas at a pressure of 1.37 atm and a
temperature of 315K. (answer: 15.9L)
29. An 8.50L tire contains 0.552 mol of gas at a temperature of 305K. What is the pressure
in atm and psi of the gas in the tire? (answer: 1.63 atm, 23.9 psi)
30. What volume does 0.556 mol of gas occupy at a pressure of 715 mmHg and a
temperature of 58°C? (answer: 16.1L)
31. Find the pressure in mmHg of a 0.133g sample of He gas in a 648mL container at a
temperature of 32°C. (answer: 976 mmHg)
32. Assuming ideal behavior, which of the following gas samples will have the greatest
volume at STP?
a. 1g of H2
b.
1g of O2
c.
1g of Ar
33. What is the density of helium gas at STP?
34. What is the density of N2 gas at STP?
35. Calculate the density of N2 gas at 125°C and a pressure of 755mmHg (R = 0.08206
L.atm/mol.K) answer: 0.852g/L
36. Calculate the density of xenon gas at a pressure of 742 mmHg and a temperature of
45°C (answer: 4.9g/L)
37. A gas has a density of 1.43g/L at a temperature of 23°C and a pressure of 0.789atm.
Calculate its molar mass. (answer: 44.0 g/mol)
38. A 1.00L mixture of helium , neon, and argon has a total pressure of 662 mmHg at 298K.
If the partial pressure of helium is 341 mmHg and the partial pressure of neon is 112
mmHg, what mass of argon is present in the mixture? (answer: 0.449g Ar)
39. What is the effusion rate ratio between H2 and O2 gas?
40. Methanol can be synthesized as follow:
CO(g) + 2H2 (g)  CH3OH(g)
What volume in liters of H2 gas at a temperature of 355K and a pressure of 738mmHg is
required to synthesize 35.7g of methane? (answer: 66.9L)
41. How many grams of water form when 1.24L of H2 gas at STP completely reacts with O2?
2H2 (g) + O2 (g)  2H2O(g)
(answer: 0.998g H2O)
Chapter 6: Thermochemistry
Key formulas or conversion factors:
 1 J = 1 kg.m2/s2
1 cal = 4.184 Joules
 1 Cal = 1000cal
1 kwh = 3.60 x 106J
 If energy flow from system to surrounding: ∆Esystem < 0 and ∆Esurrounding > 0
 Energy is lost by the system is gained by the surrounding (∆Esys = - ∆Esurr)
 If energy flow into the system: ∆Esystem > 0 and ∆Esurrounding< 0
 ∆E = q + w
 Heat absorbed by a system (q) = C x ∆T where C is heat capacity
 q = m x Cs x ∆T
Cs = specific heat capacity J/g.°C
 q rxn = -qsoln (the heat gained by the solution equals that lost by the reaction)
 Coffee cup calorimetry occurs at constant pressure and measures ∆H for a
reaction. (∆Hrxn = qrxn/mol)
∆H° rxn = Ƹ∆H°products - Ƹ∆H°reactants

Hess’s law: If reaction occurs in multiple steps: ∆H° rxn = ∆H°1 + ∆H°2…..

42. Calculate ∆H° rxn for the following reaction:
4NH3(g) + 5O2(g)  4NO(g) + 6H2O(g)
Reactant/product
(answer: -902.0kJ)
∆H°(kJ/mol)
NH3(g)
-45.9
NO(g)
+91.3
H2O(g)
-241.8
43. Calculate ∆H rxn for the reaction N2O(g) + NO2 (g)  3NO(g) from the following
information.
2NO(g) + O2(g)  2NO2(g)
∆H1 = -113.1.kJ
N2 (g) + O2 (g)  2NO(g)
∆H2 = +182.6kJ
2N2O(g)  2N2 (g) + O2(g)
∆H3 = -163.2kJ
(answer:+157.6kJ/mol)
44. Calculate ∆H rxn for the reaction 3H2(g) + O3 (g)  3H2O(g) from the following
information.
2H2(g) + O2(g)  2H2O(g)
∆H1 = -483.6kJ
3O2 (g)  2O3 (g)
∆H2 = +285.4kJ
(answer: -868.1kJ/mol)
45. Use the standard reaction enthalpies given below to determine ΔH°rxn for the following
reaction:
2 NO(g) + O2(g) → 2 NO2(g) ΔH°rxn = ?
Given:
N2(g) + O2(g) → 2 NO(g)
1/2 N2(g) + O2(g) → NO2(g)
ΔH°rxn = +183 kJ
ΔH°rxn = +33 kJ
(Answer: -117 kJ)
46. Use the standard reaction enthalpies given below to determine ΔH°rxn for the following
reaction:
4 SO3(g) → 4 S(s) + 6 O2(g) ΔH°rxn = ?
Given:
SO2(g) → S(s) + O2(g)
2 SO2(g) + O2(g) → 2 SO3(g)
Answer: 1583 kJ
ΔH°rxn = +296.8 kJ
ΔH°rxn = -197.8 kJ