A = $\frac{{\mathrm{pV}}^2{\mathrm{T}}^2}{\mathrm{n}}$ 

The SI unit for the quantity A is -

1. $\mathrm{N} {\mathrm{m}}^2 {\mathrm{K}}^2 {\mathrm{mol}}^{-1}$

2. $\mathrm{N} {\mathrm{m}}^4 \mathrm{K} {\mathrm{mol}}^{-1}$

3. $\mathrm{N} {\mathrm{m}}^2 {\mathrm{K}}^3 {\mathrm{mol}}^{-1}$ 

4. $\mathrm{N} {\mathrm{m}}^4 {\mathrm{K}}^2{\mathrm{mol}}^{-1}$

A mixture of dihydrogen and dioxygen at one bar pressure contains 20% by weight of dihydrogen. The partial pressure of dihydrogen is -

1. 0.2 bar

2. 0.7 bar

3. 0.8 bar

4. 0.6 bar