8. Hydrogen gas is collected over water at 24°C. The total pressure of the sampl
ID: 587307 • Letter: 8
Question
8. Hydrogen gas is collected over water at 24°C. The total pressure of the sample is 755 mmHg. At 24°C, the vapor pressure of water is 22 mmHg. What is the partial pressure of the hydrogen gas?
A) 22 mmHg B) 733 mmHg C) 755 mmHg D) 760. mmHg E) 777 mmHg
9. Calculate the work energy, w, gained or lost by the system when a gas expands from 15 L to 35 L against a constant external pressure of 1.5 atm.
A) -5.3 kJ B) -3.0 kJ C) +3.0 kJ D) +5.3 kJ
10. At a constant pressure of 1.50 atm what is the enthalpy change H for a reaction where the internal energy change E is 58.0 kJ and a volume increase is 12.6 L?
A) 39.1 kJ B) 56.1 kJ C) 59.9 kJ D) 76.9 kJ
Explanation / Answer
Q8
Apply
Pgas = Ptotal - PH2
Pgas = 755 - 22
PGas = 733 mm Hg
Q9
if gas expands, W is lost:
P = -P*(Vf-Vi)
W = -1.5*(35-15) = -30 atm L =-30*101.3 = -3039 J
W = -3.04 kJ
nearest is B
Q10
dE = Q - W
58 = Q - W
W = -P*dV = -1.5 * 12.6 *101.3 = -1914.57J = -1.914 kJ
Q = 58 + -1.914
Q = 56.086 kJ
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.