Question

1) Calculate [H3O+] in the following aqueous solution at 25 ∘C: [OH−]= 1.0×10−9 M .
2) Calculate [H3O+] in the following aqueous solution at 25 ∘C: [OH−]= 2.6×10−2 M .
3) Calculate [H3O+] in the following aqueous solution at 25 ∘C: [OH−]= 7.0×10−12 M .

Answer 1

The H3O+ ion is considered to be the same as the H+ ion as it is the H+ ion joined to a water molecule. The proton cannot exist in aqueous solution, due to its positive charge it is attracted to the electrons on water molecules and the symbol H3O+ is used to represent this transfer

$[H^+][OH^-]=10^{-14}\\$

1) $[OH^−]= 1.0×10^{- 9} M .$

$[H^+]=\frac{10^{-14}}{10^{-9}}=10^{-5 }M$

2) [OH^-] = $2.6\times10^{-2}$

$[H^+]=\frac{10^{-14} }{2.6\times10^{-2}}=3.84\times10^{-13}M$

3) $[OH^-]=$$7\times10^{-12}M$

$[H^+]=\frac{10^{-14}}{7\times10^{-12}}=1.43\times10^{-3}$