Instructions
As you work these matter and measurement problems, consider and explain:
- What type of question is it?
- How do you know what type of question it is?
- What information are you looking for?
- What information do they give?
- How will you go about solving this?
- Show how to solve the problem.
- Be able to answer for a different reaction, number, set of conditions, etc.
Questions
- A gas absorbs 0.0 J of heat and then performs 31.7 J of work. What is the change in internal energy of the gas?
- 63.4 J
- 31.7 J
- –63.4 J
- –31.7
- none of these
- Which of the following statements correctly describes the signs of q and w for the following exothermic process at P = 1 atm and T = 370 K? H2O(g) → H2O(l)
- q and w are negative
- q is positive, w is negative
- q is negative, w is positive
- q and w are both positive
- q and w are both zero
- Which of the following statements is correct?
- The internal energy of a system increases when more work is done by the system than heat was flowing into the system.
- The internal energy of a system decreases when work is done on the system and heat is flowing into the system.
- The system does work on the surroundings when an ideal gas expands against a constant external pressure.
- All statements are true.
- All statements are false.
- One mole of an ideal gas is expanded from a volume of 1.00 liter to a volume of 3.10 liters against a constant external pressure of 1.00 atm. How much work (in joules) is performed on the surroundings? Ignore significant figures for this problem. (T = 300 K; 1 L·atm = 101.3 J)
- 106 J
- 213 J
- 6.38 × 102 J
- 314 J
- none of these
- A fuel-air mixture is placed in a cylinder fitted with a piston. The original volume is 0.285-L. When the mixture is ignited, gases are produced and 805 J of energy is released. To what volume will the gases expand against a constant pressure of 635 mmHg, if all the energy released is converted to work to push the piston?
- 9.22 L
- 6.92 L
- 9.79 L
- 9.51 L
- 1.55 L
Use the following to answer questions 1 and 2:
Consider a gas in a 1.0 L bulb at STP that is connected via a valve to another bulb that is initially evacuated. Answer the following concerning what occurs when the valve between the two bulbs is opened.
- What is true about the value of w?
- It is greater than zero.
- It is equal to zero.
- It is less than zero.
- More information is needed.
- None of these.
- What is true about the value of ΔH?
- It is greater than zero.
- It is equal to zero.
- It is less than zero.
- More information is needed.
- None of these.
Answer the following questions:
- Which of the following properties is (are) intensive properties?
- mass
- temperature
- volume
- concentration
- energy
- I, III, and V
- II only
- II and IV
- III and IV
- I and V
- Which one of the following statements is false?
- The change in internal energy, ΔE, for a process is equal to the amount of heat absorbed at constant volume, qv.
- The change in enthalpy, ΔH, for a process is equal to the amount of heat absorbed at constant pressure, qp.
- A bomb calorimeter measures ΔH directly.
- If qp for a process is negative, the process is exothermic.
- The freezing of water is an example of an exothermic reaction.
- Consider this reaction: C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l); Δ H = –1.37 × 103 kJ
Consider the following propositions:- The reaction is endothermic
- The reaction is exothermic.
- The enthalpy term would be different if the water formed was gaseous.
- Which of these propositions is (are) true?
- I
- II
- III
- I, II
- II, III
- Two metals of equal mass with different heat capacities are subjected to the same amount of heat. Which undergoes the smallest change in temperature?
- The metal with the higher heat capacity.
- The metal with the lower heat capacity.
- Both undergo the same change in temperature.
- You need to know the initial temperatures of the metals.
- You need to know which metals you have.
- A 48.2 g sample of a metal is heated to 97.5°C and then placed in a calorimeter containing 120.0 g of water (c = 4.18 J/g°C) at 21.3°C. The final temperature of the water is 24.5°C. Which metal was used?
- Aluminum (c = 0.89 J/g°C)
- Iron (c = 0.45 J/g°C)
- Copper (c = 0.20 J/g°C)
- Lead (c = 0.14 J/g°C)
- none of these
- The enthalpy of fusion of ice is 6.020 kJ/mol. The heat capacity of liquid water is 75.4 J/mol·°C. What is the smallest number of ice cubes at 0°C, each containing one mole of water, necessary to cool 500 g of liquid water initially at 20°C to 0°C?
- 1
- 7
- 14
- 15
- 126
- Consider the reaction H2(g) + O2(g) → H2O(l) ΔH° = –286 kJ
Which of the following is true?- The reaction is exothermic.
- The reaction is endothermic.
- The enthalpy of the products is less than that of the reactants.
- Heat is absorbed by the system.
- Both A and C are true.
- If 5.0 kJ of energy is added to a 15.5-g sample of water at 10°C, the water is _______.
- boiling
- completely vaporized
- frozen solid
- decomposed
- still a liquid
- A chunk of lead at 91.3°C was added to 200.0 g of water at 15.5°C. The specific heat of lead is 0.129 J/g°C, and the specific heat of water is 4.18 J/g°C. When the temperature stabilized, the temperature of the mixture was 20.5°C. Assuming no heat was lost to the surroundings, what was the mass of lead added?
- 1.88 kg
- 355 g
- 427 g
- 458 g
- none of these
- What is the specific heat capacity of graphite if it requires 266 J to raise the temperature of 15 grams of graphite by 25°C?
- 1.4 J/g°C
- 0.71 J/g°C
- 0.43 J/g°C
- 0.60 J/g°C
- none of these
- Consider this reaction: When a 11.6-g sample of ethyl alcohol (molar mass = 46.07 g/mol) is burned, how much energy is released as heat?
- 0.252 kJ
- 0.345 kJ
- 3.45 × 102 kJ
- 1.59 × 104 kJ
- 3.97 kJ
- Given the equation S(s) + O2(g) → SO2(g), ΔH = –296 kJ, which of the following statement(s) is (are) true?
- The reaction is exothermic.
- When 0.500 mole sulfur is reacted, 148 kJ of energy is released.
- When 32.0 g of sulfur are burned, 2.96 × 105 J of energy is released.
- All are true.
- None is true.
- I and II are true.
- I and III are true.
- Only II is true.
- Consider the following specific heats of metals.
Metal Specific Heat Zinc 0.387 J/(g°C Magnesium 1.02 J/(g°C Mercury 0.138 J/(g°C Silver 0.237 J/(g°C Bismuth 0.123 J/(g°C If the same amount of heat is added to 25.0 g of each of the metals, which are all at the same initial temperature, which metal will have the highest temperature?
- Zinc
- Magnesium
- Mercury
- Silver
- Bismuth
- The specific heat capacities of metals are relatively low.
- True
- False
- At 25°C, the following heats of reaction are known:
ΔH (kJ/mol) 2ClF + O2 → Cl2O + F2O 167.4 2ClF + O2 → Cl2O + F2O 341.4 2F2 + O2 → 2F2O –43.4 At the same temperature, calculate ΔH for the reaction: ClF + F2 → ClF3
- –217.5 kJ/mol
- –130.2 kJ/mol
- +217.5 kJ/mol
- –108.7 kJ/mol
- none of these
- Given the heats of the following reactions:
ΔH°(kJ) I. P4(s) + 6Cl2(g) → 4PCl3(g) –1225.6 II. P4(s) + 5O2(g) → P4O10(s) –2967.3 III. PCl3(g) + Cl2(g) → PCl5(g) –84.2 IV. PCl3(g) + O2(g) → Cl3PO(g) –285.7 Calculate the value of ΔH° for the reaction below:
P4O10(s) + 6PCl5(g)
- –110.5 kJ
- –610.1 kJ
- –2682.2 kJ
- –7555.0 kJ
- None of these is within 5% of the correct answer.
- Using the following thermochemical data, calculate ΔHf° of Er2O3(s).
2ErCl3(s) + 3H2O(l) → Er2O3(s) + 6HCl(g) H° = 403.1 kJ/mol 2Er(s) + 3Cl2(g) → 2ErCl3(s) H° = –1997.4 kJ/mol 4HCl(g) + O2(g) → 2Cl2(g) + 2H2O(l) H° = –202.4 kJ/mol - –1897.9 kJ/mol
- –1796.7 kJ/mol
- 2602.9 kJ/mol
- –2198.1 kJ/mol
- 1391.9 kJ/mol
- Given the following:
Cu2O(s) + O2(g) → 2CuO(s) ΔH° = –144 kJ Cu2O(s) → Cu(s) + CuO(s) ΔH° = +11 kJ Calculate the standard enthalpy of formation of CuO(s).
- –166 kJ
- –299 kJ
- +299 kJ
- +155 kJ
- –155 kJ
- The heat combustion of acetylene, C2H2(g), at 25°C is –1299 kJ/mol. At this temperature, ΔHf° values for CO2(g) and H2O(l) are –393 and –286 kJ/mol, respectively. Calculate ΔHf° for acetylene.
- 2376 kJ/mol
- 625 kJ/mol
- 227 kJ/mol
- –625 kJ/mol
- –227 kJ/mol
- For the reaction:
AgI(s) + Br2(g) → AgBr(s) + I2(s), ΔH°= –54.0 kJ
ΔHf° for AgBr(s) = –100.4 kJ/mol
ΔHf° for Br2(g) = +30.9 kJ/mol
What is the value of ΔHf° for AgI(s)?- –123.5 kJ/mol
- +77.3 kJ/mol
- +61.8 kJ/mol
- –77.3 kJ/mol
- –61.8 kJ/mol
- For which of the following reaction(s) is the enthalpy change for the reaction not equal to ΔHf° of the product?
- 2H(g) → H2(g)
- H2(g) + O2(g) → H2O2(l)
- H2O(l) + O(g) → H2O2(l)
- I
- II
- III
- I and III
- II and III
- The following statements concerning petroleum are all true except:
- It is a thick, dark liquid composed mostly of hydrocarbons.
- It must be separated into fractions (by boiling) in order to be used efficiently.
- Some of the commercial uses of petroleum fractions include gasoline and kerosene.
- It was probably formed from the remains of ancient marine organisms.
- All of its hydrocarbon chains contain the same number of carbon atoms.
- What is the coal with the highest energy available per unit burned?
- Lignite
- Subbituminous
- Bituminous
- Anthracite
- They are equal in energy value.
- Which of the following is both a greenhouse gas and a fuel?
- carbon dioxide
- coal
- freon
- methane
- nitrogen
- Which of the following is not being considered as an energy source for the future?
- ethanol
- methanol
- seed oil
- shale oil
- carbon dioxide