The amount of heat energy required to raise the temperature of 1 g of Helium at NTP, from `T_(1)` K to `T_(2)` K is :

Options

A. `(3)/(4)N_(a)k_(B)((T_(2))/(T_(1)))`
B. `(3)/(8)N_(a)k_(b)(T_(2)-T_(1))`
C. `(3)/(2)N_(a)k_(B)(T_(2)-T_(1))`
D. `(3)/(4)N_(a)k_(B)(T_(2)-T_(1))`

Answer

B

Explanation

Number of moles in 1 gram of He. `n=(1)/(4)`
`C_(v) =(3)/(2)R` , rise in temp. `Delta T= T_(2)-T_(1)`
`:. Delta Q =n C_(v) Delta T =(1)/(4) ((3)/(2)R) (T_(2)-T_(1))`
`Delta Q = (3)/(8)k_(B) N_(a) (T_(2)-T_(1))`
where `k_(B)` is Boltzmann constant and `N_(a)` is Avogadro's number.