Question

Ask Your Teacher A 1.04-mole sample of ammonia at 11.0 atm and 25°C in a cylinder fitted with a movable piston expands against a constant external pressure of 1.00 atm. At equilibrium, the pressure and volume of the gas are 1.00 atm and 24.2 L, respectively. (The heat capacity, CP, of ammonia at 25°C is 35.66 J·K−1·mol−1.)
(a) Calculate the final temperature of the sample.
(b) Calculate the values of q; w, and DU for the process.

Answer 1

Answer:

Explanation:

a) Volume of the gas nRT / P

= 1,04 X 8.3 X 298 / 11 X 10⁵ m³

= 233.85 x 10⁻⁵ m³

= 233 x 10⁻² L

2.33 L

P₁V₁ / T₁ =P₂V₂/T₂

(11 X 2.33) / 298 = (1 X 24.2) / T

T = 281.37 K

= 8.37 degree

b ) w = p x change in volume

= 10⁵ x ( 24.2 - 2.33 ) x 10⁻³ J

= 21.87 X 10² J

2187 J

q  = n x Cp x (25 - 8.37 )

= 1.04 x 35.66x 16.63 J

= 616.65 J

ΔU = Q - W

= 616.65  - 2187 J

= - 1570.35 J

=

=