Problem 21
Heat \(Q\) flows into a monatomic ideal gas, and the volume increases while the pressure is kept constant. What fraction of the heat energy is used to do the expansion work of the gas?
Problem 22
Three moles of an ideal monatomic gas expands at a constant pressure of 2.50 atm; the volume of the gas changes from 3.20 \(\times\) 10\(^{-2}\) m\(^3\) to 4.50 \(\times\) 10\(^{-2}\) m\(^3\). Calculate (a) the initial and final temperatures of the gas; (b) the amount of work the gas does in expanding; (c) the amount of heat added to the gas; (d) the change in internal energy of the gas.
Problem 24
Propane gas (\(C_3H_8\)) behaves like an ideal gas with \(_\Upsilon\) = 1.127. Determine the molar heat capacity at constant volume and the molar heat capacity at constant pressure.
Problem 26
Five moles of monatomic ideal gas have initial pressure 2.50 \(\times\) 10\(^3\) Pa and initial volume 2.10 m\(^3\). While undergoing an adiabatic expansion, the gas does 1480 J of work. What is the final pressure of the gas after the expansion?
Problem 28
The engine of a Ferrari F355 F1 sports car takes in air at 20.0\(^\circ\)C and 1.00 atm and compresses it adiabatically to 0.0900 times the original volume. The air may be treated as an ideal gas with \(_\Upsilon\) = 1.40. (a) Draw a \(pV\)-diagram for this process. (b) Find the final temperature and pressure.
Problem 29
During an adiabatic expansion the temperature of 0.450 mol of argon (Ar) drops from 66.0\(^\circ\)C to 10.0\(^\circ\)C. The argon may be treated as an ideal gas. (a) Draw a \(pV\)-diagram for this process. (b) How much work does the gas do? (c) What is the change in internal energy of the gas?
Problem 30
A player bounces a basketball on the floor, compressing it to 80.0% of its original volume. The air (assume it is essentially N\(_2\) gas) inside the ball is originally at 20.0\(^\circ\)C and 2.00 atm. The ball's inside diameter is 23.9 cm. (a) What temperature does the air in the ball reach at its maximum compression? Assume the compression is adiabatic and treat the gas as ideal. (b) By how much does the internal energy of the air change between the ball's original state and its maximum compression?
Problem 31
On a warm summer day, a large mass of air (atmospheric pressure 1.01 \(\times\) 10\(^5\) Pa) is heated by the ground to 26.0\(^\circ\)C and then begins to rise through the cooler surrounding air. (This can be treated approximately as an adiabatic process; why?) Calculate the temperature of the air mass when it has risen to a level at which atmospheric pressure is only 0.850 \(\times\) 10\(^5\) Pa. Assume that air is an ideal gas, with \(\Upsilon\) = 1.40. (This rate of cooling for dry, rising air, corresponding to roughly 1 C\(^\circ\) per 100 m of altitude, is called the dry \(adiabatic\) \(lapse\) \(rate\).)
Problem 32
A cylinder contains 0.100 mol of an ideal monatomic gas. Initially the gas is at 1.00 \(\times\) 10\(^5 \)Pa and occupies a volume of 2.50 \(\times\) 10\(^{-3}\) m\(^3\). (a) Find the initial temperature of the gas in kelvins. (b) If the gas is allowed to expand to twice the initial volume, find the final temperature (in kelvins) and pressure of the gas if the expansion is (i) isothermal; (ii) isobaric; (iii) adiabatic.
Problem 40
Three moles of argon gas (assumed to be an ideal gas) originally at 1.50 \(\times\) 10\(^4\) Pa and a volume of 0.0280 m\(^3\) are first heated and expanded at constant pressure to a volume of 0.0435 m\(^3\), then heated at constant volume until the pressure reaches 3.50 \(\times\) 10\(^4\) Pa, then cooled and compressed at constant pressure until the volume is again 0.0280 m\(^3\), and finally cooled at constant volume until the pressure drops to its original value of 1.50 \(\times\) 10\(^4\) Pa. (a) Draw the \(pV\)-diagram for this cycle. (b) Calculate the total work done by (or on) the gas during the cycle. (c) Calculate the net heat exchanged with the surroundings. Does the gas gain or lose heat overall?
