Question

The SI unit of universal gas constant (R) is

• A. Watt $K^{- 1}mol^{- 1}$
• B. Newton $K^{- 1}mol^{- 1}$
• C. Joule $K^{- 1}mol^{- 1}$
• D. $ErgK^{- 1}mol^{- 1}$

Answer 1

Answer: (C)

Joule $K^{- 1}mol^{- 1}$

Answer 2

Ideal gas equation $PV = nRT$

$\therefore\lbrack R\rbrack = \frac{\lbrack P\rbrack\lbrack V\rbrack}{\lbrack nT\rbrack} = \frac{\lbrack ML^{- 1}T^{- 2}\rbrack\lbrack L^{3}\rbrack}{\lbrack mole\rbrack\lbrack K\rbrack} = \frac{\lbrack ML^{2}T^{- 2}\rbrack}{\lbrack mole\rbrack \times \lbrack K\rbrack}$

So the unit will be Joule$K^{- 1}mol^{- 1}$.