A bomb calorimeter has a heat capacity of 3.18 kJ/K. When 0.0038 mol of a gas is burned in the calorimeter, the temperature increased from 25.0°C to 27.3°C. Calculate the energy released by the combustion of one mole of the gas.
7.3 kJ
-1.9 x 103 kJ
2.8 x 10-2 kJ
-2.8 x 10-2 kJ
-3.6 x 102 kJ
The specific heat of iron is 0.450 J/(g·°C). How much heat is required to raise the temperature of a 5.00 gram sample of iron from 22°C to 53°C?
69.8 J
155 J
-43 J
344 J
18 J
A gas absorbs 2.5 J of heat and then performs 13.1 J of work. The change in internal energy of the gas is:
5.2 J
-15.6 J
15.6 J
10.6 J
-10.6 J
As a result of an exothermic reaction,
the energy of the sytem and the energy of the surroundings are increased.
the energy of the system is increased and the energy of the surroundings are decreased.
the energy of the system is decreased and the energy of the surroundings are increased.
the energy of the system and the energy of the surroundings are decreased.
None of these are accurate
Calculate the work done for the expansion of oxygen gas from 2.5 liters to 3.7 liters against a pressure of 720 torr.
-1.14 liter·atm
864 liter·atm
-864 liter·atm
8.79 liter·atm
-4.78 liter·atm
For a particular process, q = -117 kJ and w = 73 kJ. How many of the following statements are true?
Work is done on the system
Heat is released to the surroundings
The change in internal energy is 44 kj
This energy change could occur as a liquid vaporizes
The change can only occur at constant pressure
Only one statement is true.
Two of the statements are true.
Three of the statements are true.
Four of the statements are true.
All five of the statements are true.
The specific heat of liquid water is 4.18 J/°C·g and the specific heat of carbon is 0.71 J/°C·g. A 10 gram sample of water and a 10 gram sample of carbon are each subjected to 155 J of heat. If both samples started at 25°C, which substance will have the higher final temperature, and by what magnitude?
water, by 3.47°C
water, by 28.7°C
carbon, by 18.1°C
carbon, by 215°C
Neither. They will have the same final temperature because the started at the same temperature and were exposed to the same quantity of heat.
A 47.5 gram sample of a metal at a temperature of 425°C is placed in 1.00 liters (1000 grams) of water which had an initial temperature of 18°C. What is the specific heat capacity of the metal if the final temperature of the metal and water at equilibrium is 21°C? (The specific heat capacity of water is 4.18 J/°C·g.
0.65 J/°C·g
12.54 J/°C·g
0.03 J/°C·g
1.47 J/°C·g
-0.75 J/°C·g
20.0 mL of pure water at 285 K is mixed with 48 mL of water at 315 K. What is the final temperature of the mixture in kelvins?
275 K
318 K
290 K
306 K
None of these
Calculate the work associated with the compression of a gas from 86 liters to 48 liters at a constant pressure of 2.0 atm.
-76 L·atm
76 L·atm
268 L·atm
13.5 L·atm
0.050 L·atm
Which of the following fuel sources is not renewable?
ethanol
methanol
seed oil
shale oil
hydrogen
Calculate the heat evolved in the formation of 1 mole of PbSO4(s) from its elements, given the following:
Pb(s) + S(s) → PbS(s) + 94 kJ/mol
PbS(s) + 2O2(g) → PbSO4(s) + 824 kJ/mol
-918 kJ/mol
-730 kJ/mol
730 kJ/mol
918 kJ/mol
None of these
Consider the following numbered processes:
1) A → 2B + DH1 2) B → C + D + DH2 3) E → 2D + DH3
DH for the process A → 2C + E is
DH1 + DH2 + DH3
DH1 - 2DH3
DH1 + 2DH2 - DH3
2DH1 + DH2 - DH3
2DH1 + 2DH2 - DH3
Given the following data:
K(s) → K(g) + 90. kJ
K(g) → K+(g) + e- + 419 kJ
F2(g) → 2F(g) + 151 kJ
F-(g) → F(g) + e- + 333 kJ
KF(s) → K+(g) + F-(g) + 803 kJ
Calculate DH for the reaction K(s) +1/2F2(g) → KF(s)
317 kJ
-401 kJ
-1721 kJ
-552 kJ
1796 kJ
A sample of wood has a heat of combustion of 3.29 kJ/g. What quantity of the wood must be burned to heat 250. g of water from 18°C to 85°C? Once again, the specific heat capacity of water is 4.18 J/°C·g.