The first and second dissociation constants of a diprotic acid $H_2A$ are $1.0 \times 10^{-5}$ and $5.0 \times 10^{-10}$ respectively. The overall dissociation constant of the acid is:

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

If $10\%$ of a $5 \times 10^{-3} \, M \, H_2CO_3$ solution dissociates,then the concentration of $H^{+}$ ions is equal to $......$.

What is the ratio of the number of $H^{+}$ ions to the number of $H_2O$ molecules in $1 \ L$ of water?

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:

The initial rate of hydrolysis of methyl acetate $(1 \ M)$ by a weak acid $(HA, 1 \ M)$ is $1/100$th of that of a strong acid $(HX, 1 \ M)$ at $25^{\circ} C$. The $K_a$ of $HA$ is: