Two moles of ideal helium gas are in a rubber balloon at 30° C. The balloon is fully expandable and can be assumed to require no energy in its expansion. The temperature of the gas in the balloon is slowly changed to 35° C. The amount of heat required in raising the temperature is nearly (take R =8.31 J / mol . K )

Question

Two moles of ideal helium gas are in a rubber balloon at 30° C. The balloon is fully expandable and can be assumed to require no energy in its expansion. The temperature of the gas in the balloon is slowly changed to 35° C. The amount of heat required in raising the temperature is nearly (take R =8.31 J / mol . K ) (A) 62 J (B) 104 J (C) 124 J (D) 208 J

Tardigrade Admin · Accepted Answer

Δ Q =n Cp Δ T (Isobaric process) =2 × (5/2) R ×(35-30) =208 J

62 J

104 J

124 J

208 J

ΔQ=nCp​ΔT (Isobaric process) =2×25​R×(35−30) =208J

$Δ Q = n C_{p} Δ T$ (Isobaric process)
$= 2 \times \frac{5}{2} R \times (35 - 30)$
$= 208 J$