Question

At NTP the mass of one litre of air is 1.293 gm. The value of specific gas constant will be

• A. 0.29 J/K-gm
• B. 4.2 J/K-gm
• C. 8.3 J/K-gm
• D. 16.5 J/K-gm

Answer 1

Answer: (A)

0.29 J/K-gm

Answer 2

For m gm of gas $PV = mrT$

Substituting the given and known values

$r = \frac{1.015 \times 10^{5} \times 10^{- 3}}{1.293 \times 273} = 0.29J/K - gm$