The hydrogen ion concentration of a $0.1 \ N$ solution of $CH_3COOH$,which is $30 \%$ dissociated,is (in $M$)

The species present in solution when $CO_2$ is dissolved in water are

Arrange the following resultant mixtures in increasing order of their pH values:
$A$. $10 \text{ mL } 0.2 \text{ M } Ca(OH)_2 + 25 \text{ mL } 0.1 \text{ M } HCl$
$B$. $10 \text{ mL } 0.01 \text{ M } H_2SO_4 + 10 \text{ mL } 0.01 \text{ M } Ca(OH)_2$
$C$. $10 \text{ mL } 0.1 \text{ M } H_2SO_4 + 10 \text{ mL } 0.1 \text{ M } KOH$
Choose the correct answer from the options given below:

$A$ certain weak base has a dissociation constant $2 \times 10^{-5}$. The equilibrium constant for its neutralization reaction with a strong acid is

What is the $pH$ of a solution containing $10 \, mL$ of $0.1 \, M \, NaOH$ and $10 \, mL$ of $0.05 \, M \, H_2SO_4$?

What will be the change in acidity if
$(i)$ $CuSO_4$ is added in saturated $(NH_4)_2SO_4$ solution
$(ii)$ $SbF_5$ is added in anhydrous $HF$?