Question

Q.1 H₂S a toxic gas with rotten egg like smell, is used for the qualitative analysis. If the solubility of H₂S in H₂O at STP is 0.195m, Calculate Henry 's Law constant.

Answer 1

We can say that

0.195 m means 0.195 moles of H₂S is contained in 1000g of solvent.

So, number of moles of water = 1000/18= 55.55

and x_H2S= number of moles of H₂S/( number of moles of water + number of moles of H₂S)

x_H2S≈ number of moles of H₂S/number of moles of water

x_H2S= 0.195/ 55.55= 3.51 * 10^-3

^{At STP, pressure = 0.987 bar}

k_H= p_H2S/x_H2S

k_H= 0.987 / (3.51 * 10^-3) bar= 281.19 bar