Question 477: Thermodynamics & KTG

Question

A 15 g mass of nitrogen gas is enclosed in a vessel at a temperature 27oC. Amount of heat transferred to the gas, so that rms  velocity of molecules is doubled, is about : [Take R = 8.3 J/K mole]

Accepted Answer

We know,
V
rms
$$ \propto $$ $$\sqrt T $$
So, to make V
rms
double we have to make temperature 4 times.
$$ 	herefore $$   Final temperature = 300  $$ 	imes $$ 4 = 1200 K
As N
2
gas present in the closed vessel
So it is a isochoric process.
$$ 	herefore $$   Q =
n
C
v
$$\Delta $$ T
= $${{15} \over {28}} 	imes \left( {{5 \over 2}R} ight)\left( {1200 - 300} ight)$$
= 10000 J
= 10 kJ

Answer

0.9 kJ

Answer

6 kJ

Answer

10 kJ

Answer

14 kJ

Thermodynamics & KTG

A 15 g mass of nitrogen gas is enclosed in a vessel at a temperature 27oC. Amount of heat transferred to the gas, so that rms velocity of molecules is doubled, is about : [Take R = 8.3 J/K mole]

Choose the correct answer: