The approximate pH of a 0.1 M aqueous H2S solution is ( K1 and K2 for H2S are 1× 10- 7 and 1.3× 10- 13 respectively at 25 ° C)

Question

The approximate pH of a 0.1 M aqueous H2S solution is ( K1 and K2 for H2S are 1× 10- 7 and 1.3× 10- 13 respectively at 25 ° C) (A) 4 (B) 2 (C) 8 (D) 6

Tardigrade Admin · Accepted Answer

Second dissociation of H2S is negligible from data H2Sleftharpoons H++HS- [.H+].=[.HS-].=x K1=([. H+ ]. [. H S- ]./[. H2 S ].) 1× 10- 7=(x2/0.1) So x=10- 4 pH=-log [.H+]. =-log 10- 4 =4log 10=4 .

Q. The approximate pH of a 0.1 M aqueous H2​S solution is ( K1​ and K2​ for H2​S are 1×10−7 and 1.3×10−13 respectively at 25 ∘ C)

4

2

8

6

Second dissociation of H2​S is negligible from data H2​S⇌H++HS− [H+]=[HS−]=x K1​=[H2​S][H+][HS−]​ 1×10−7=0.1x2​ So x=10−4 pH=−log[H+] =−log10−4 =4log10=4 .

Q. The approximate pH of a 0.1 M aqueous $H_{2} S$ solution is ( $K_{1}$ and $K_{2}$ for $H_{2} S$ are $1 \times 1 0^{- 7}$ and $1.3 \times 1 0^{- 13}$ respectively at 25 $^{\circ}$ C)