Contoh-contoh soal di ambil dari Buku Serway buku 1 dan 2
Bab 19
1. A constant-volume gas thermometer is
calibrated in dry ice (that is, carbon dioxide in the solid state, which has a
temperature of –80.0°C) and in boiling ethyl alcohol (78.0°C). The two
pressures are 0.900 atm and 1.635 atm.
(a) What Celsius value of absolute zero does the calibration yield? What is the pressure at (b) the freezing
point of water and (c) the boiling point of water?
6. On a Strange temperature scale, the freezing point of water
is –15.0°S and the boiling point is +60.0°S.
Develop a linear conversion equation between this temperature
scale and the Celsius scale.
9. A copper telephone wire has essentially
no sag between poles 35.0 m apart on a winter day when the temperature is
–20.0°C. How much longer is the wire on
a summer day when
TC = 35.0°C?
21. A hollow aluminum cylinder 20.0 cm deep
has an internal capacity of 2.000 L at 20.0°C. It is completely filled with
turpentine, and then slowly warmed to 80.0°C. (a) How much turpentine
overflows? (b) If the cylinder is then cooled back to 20.0°C, how far below the
cylinder's rim does the turpentine’s surface recede?
26. Gas is contained in an 8.00-L vessel at a
temperature of 20.0°C and a pressure of 9.00 atm. (a) Determine the number of
moles of gas in the vessel. (b) How many molecules are there in the vessel?
47.
A mercury thermometer is constructed as shown in Figure P19.47. The capillary
tube has a diameter of
0.004
00 cm, and the bulb has a diameter of 0.250 cm. Neglecting the expansion of the
glass, find the change in height of the mercury column that occurs with a
temperature change of 30.0°C.
Figure P19.47 Problems 47 and 48
Bab 20
4. A 50.0-g sample of copper is at 25.0°C. If 1 200 J of energy is added to it by heat,
what is the final temperature of the copper?
8. An aluminum cup of mass 200 g contains 800 g of
water in thermal equilibrium at 80.0°C. The combination of cup and water is
cooled uniformly so that the temperature decreases by 1.50°C per minute. At
what rate is energy being removed by heat? Express your answer in watts.
12. If water with a mass mh at
temperature Th is poured into an aluminum cup of mass mAl
containing mass mc of water at Tc, where Th
> Tc, what is the equilibrium temperature of the system?
15. How much energy is required to change a 40.0-g ice cube from
ice at –10.0°C to steam at 110°C?
23. A sample of ideal gas is expanded to
twice its original volume of 1.00 m3 in a quasi-static process
for which P = aV 2, with a = 5.00 atm/m6,
as shown in Figure P20.23. How much work is done on the expanding gas?
Figure P20.23
29. A thermodynamic system undergoes a
process in which its internal energy decreases by 500 J. At the same time, 220
J of work is done on the system. Find
the energy transferred to or from it by heat.
30. A gas is taken through the cyclic process described in Figure
P20.30. (a) Find the net energy transferred to the system by heat during one
complete cycle. (b) What If? If the cycle is reversed—that is, the
process follows the path ACBA—what is the net energy input per cycle by
heat?
Figure P20.30 Problems 30 and 31
32. A sample of an ideal gas goes through the process shown in
Figure P20.32. From A to B,
the process is adiabatic; from B to C, it is isobaric with
100 kJ
of energy entering the system by heat.
From C to D, the process is isothermal; from D to A,
it is isobaric with 150 kJ of energy leaving the system by heat. Determine the
difference in internal energy Eint,B – Eint,A.
Figure P20.32
Bab 21
4. A
2.00-mol sample of oxygen gas is confined to a 5.00-L vessel at a pressure of
8.00 atm. Find the average translational kinetic energy of an oxygen molecule
under these conditions.
13. A 1.00-mol sample of hydrogen gas is
heated at constant pressure from 300 K to 420 K. Calculate (a) the energy
transferred to the gas by heat, (b) the increase in its internal energy, and
(c) the work done on the gas.
14. A
1.00-mol sample of air (a diatomic ideal gas) at 300 K, confined in a cylinder
under a heavy piston, occupies a volume of 5.00 L. Determine the final volume of the gas after
4.40 kJ of energy is transferred to the air by heat.
25. A 2.00-mol sample of a diatomic ideal gas
expands slowly and adiabatically from a pressure of 5.00 atm and a volume of
12.0 L to a final volume of 30.0 L. (a) What is the final pressure of the gas?
(b) What are the initial and final temperatures? (c) Find Q, W, and DEint.
Bab 22
4. Heat engine X takes in four
times more energy by heat from the hot reservoir than heat engine Y. Engine X delivers two times more work,
and it rejects seven times more energy by heat to the cold reservoir than heat
engine Y. Find the efficiency of
(a) heat engine X and (b) heat engine Y.
35. An ice tray contains 500 g of liquid water at 0°C. Calculate
the change in entropy of the water as it freezes slowly and completely at 0°C.
37. Calculate the change in entropy of 250 g
of water heated slowly from 20.0°C to 80.0°C. (Suggestion: Note that dQ
= mc dT.)
62. A 1.00-mol sample of an ideal monatomic
gas is taken through the cycle shown in Figure P22.62. The process A ®B is a reversible isothermal
expansion. Calculate (a) the net work done by the gas, (b) the energy added to
the gas by heat, (c) the energy exhausted from the gas by heat, and (d) the
efficiency of the cycle.
Figure P22.62
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