Question

Write the equation that represents the Kh of LiHSO3. O А HSO3 + H20=H30+ + 50%- O B HSO3 + H2O = OH + H2SO3 o с so- + H2O=OH- + HSOZ o D LiHSO3- > HCO3 + K+ E H2SO3 + H2O=H3O+ + HSO3

Answer 1

The expression for K_b ( i.e base dissociation constant ) tells about  the ability of the base to gain H⁺ ion from the aqueous medium generally . When any species accepts H⁺ ion from the medium then this base forms its conjugate acid.

As water can acts as both acid and base so , here it is acting as an acid to release its H⁺ ion .

Hence the K_b expression should be like

B) HSO₃^- + H₂O $\rightarrow$ OH^- + H₂SO₃

Here Lithium bisulfite ions dissociate completely being an strong electrolyte so , its bisulfite ion reacts with water to form sulphurous acid ( H₂SO₃ ) and hydroxyl ions ( i.e OH^- ) .

K_b = [ OH^- ] [ H₂SO₃ ] / [ HSO₃^- ]

As here water is not included in this expression because it is present in excess and its concentration is not changing with time .