The solubility of salt $\text{AX}_2$ is $6 \times 10^{-12}\ \text{mol dm}^{-3}$. What is solubility product of the salt ?

An organic monobasic acid has dissociation constant $1.96 \times 10^{-8}$. What is its percentage dissociation in $0.01$ M solution ?

Which of the following aqueous salt solutions has the least pH value ?

What is the oxidation number of carbon in oxalic acid ?