Honors Chemistry

Answers to Chapter 5 Study Questions

 

1. a) STP: PT = 1 atm; T = 273 K; ; nT = 0.039 + 0.010 + 0.001 = 0.050 moles

= 0.20 atm

 

b) V = ?; STP: T = 273 K, PT = 1 atm; nT = 0.050 mol; PV = nRT

= 1.1 L

 

2. a) PT = PH2 + PH2O; Find PH2O in Table from lab report; at 19C, PH2O = 16 mmHg

PH2 = PT - PH2O = 756 - 16 = 740. mmHg

b) = 0.974 atm

 

3. V1 = 600. cm3; T1 = 25C = 298 K; P1 = 750. mmHg

V2 = 480. cm3; T2 = 41C = 314 K; P2 = ?

 

4. = 0.178 g/L

 

5. a) 2 C4H10(g) + 13 O2(g) 10 H2O(l) + 8 CO2(g)

b) = 3.2 L O2

c) = 17.9 L CO2

d) = 7.5 x 1023 molecules

 

6. n = 1 mole; T = 68C = 341 K; P = 2.00 atm; V = ?

14.0 L

7. = 11.2 L

 

= 3.93 g/L

 

9. Find molar volume at 710 mmHg and 36C and then use conversion factors:

T = 36 + 273 = 309 K; = 0.934 atm

27.1 L

= 3.70 L O2

 

10. ; so use PV = nRT to calculate n; T = 29 + 273 = 302 K; P = 1 atm

= 28.0 g/mole

 

11. = 0.341 mol CO2; = 0.750 mole CH4;

= 15.7 L

 

12. PH2= PT - PH2O; At 22C, PH2O = 20 mm Hg; PH2 = 750 mmHg - 20 mmHg = 730 mmHg

= 0.960 atm; T = 22 + 273 = 295 K;

= 0.119 mol H2 = n

3.00 L