Respuestas Cap. 19 Fisica Tippens

Chapter 19. Thermal Properties of Matter

General Gas Laws: Initial and Final States
19-1. An ideal gas occupies a volume of 4.00 m3 at 200 kPa absolute pressure. What will be the new pressure if the gas is slowly compressed to 2.00 m3 at constant temperature?
P2 = 400 kPa

19-2. The absolute pressure of a sample of ideal gas is 300 kPa at a volume of 2.6 m3. If thepressure decreases to 101 kPa at constant temperature, what is the new volume?
V2 = 7.72 m3

19-3. Two hundred cubic centimeters of an ideal gas at 200C expands to a volume of 212 cm3 at constant pressure. What is the final temperature. [ T1 = 200 + 2730 = 293 K ]
; T2 = 310.6 K
tC = 310.60 – 2730 = 37.60C; tC = 37.60C

19-4. The temperature of a gassample decreases from 550C to 250C at constant pressure. If the initial volume was 400 mL, what is the final volume?
T1 = 550 + 2730 = 328 K; T2 = 250 + 2730 = 298 K; V1 = 400 mL
V2 = 363 mL

19-5. A steel cylinder contains an ideal gas at 270C. The gauge pressure is 140 kPa. If the temperature of the container increases to 790C, what is the new gauge pressure?
T1 = 270 +2730 = 300 K; T2 = 790 + 2730 = 352 K;
P1 = 140 kPa + 101.3 kPa = 241.3 kPa;

Gauge Pressure = 283.1 kPa – 101.3 kPa; P2 = 182 kPa

19-6. The absolute pressure of a sample of gas initially at 300 K doubles as the volume remains constant. What is the new temperature? [ P2 = 2P1 ]
; T2 = 600 K

19-7. A steel cylinder contains 2.00 kg of an ideal gas.Overnight the temperature and volume remain constant, but the absolute pressure decreases from 500 kPa down to 450 kPa. How many grams of the gas leaked out over night?
; m2 = 1.80 kg
Lost = 2.00 kg – 1.80 kg = 0.200 kg; Amt. Leaked = 200 g

19-8. Five liters of a gas at 250C has an absolute pressure of 200 kPa. If the absolute pressure reduces to 120 kPa and the temperatureincreases to 600C, what is the final volume?
T1 = 250 + 2730 = 298 K; T2 = 600 + 2730 = 333 K

V2 = 9.31 L
19-9. An air compressor takes in 2 m3 of air at 200C and one atmosphere (101.3 kPa) pressure. If the compressor discharges into a 0.3-m3 tank at an absolute pressure of 1500 kPA, what is the temperature of the discharged air? [ T1 = 200 + 2730 = 293 K ]
; T2 = 651 K19-10. A 6-L tank holds a sample of gas under an absolute pressure of 600 kPa and a temperature of 570C. What will be the new pressure if the same sample of gas is placed into a 3-L container at 70C. [ T1 = 570 + 2730 = 330 K; T2 = 70 + 2730 = 280 K ]
; P2 = 1020 kPa

19-11. If 0.8 –L of a gas at 100C is heated to 900C at constant pressure. What is the new volume?
T1= 100 + 2730 = 283 K; T2 = 900 + 2730 = 363 K
; V2 = 1.03 L

19-12. The inside of an automobile tire is under a gauge pressure of 30 lb/in.2 at 40C. After several hours, the inside air temperature rises to 500C. Assuming constant volume, what is the new gauge pressure?
P1 = 30 lb/in.2 + 14.7 lb/in.2 = 44.7 lb/in.2
T1 = 2730 + 40 = 277 K; T2 = 2730 + 500 = 323 K

P2 =52.1 lb/in.2 – 14.7 lb/in.2 = 37.4 lb/in.2; P2 = 37.4 lb/in.2
19-13. A 2-L sample of gas has an absolute pressure of 300 kPa at 300 K. If both pressure and volume experience a two-fold increase, what is the final temperature?
T2 = 1200 K

Molecular Mass and the Mole
19-14. How many moles are contained in 600 g of air (M = 29 g/mole)?
; n = 20.7 mol

19-15. How manymoles of gas are there in 400 g of nitrogen gas (M = 28 g/mole)? How many molecules are in this sample?
; n = 14.3 mol
;
N = 8.60 x 1024 molecules

19-16. What is the mass of a 4-mol sample of air (M = 29 g/mol)?
m = 116 g

19-17. How many grams of hydrogen gas (M = 2 g/mol) are there in 3.0 moles of hydrogen? How many grams of air (M = 29 g/mol) are...