To neutralize completely $20 \ mL$ of $0.1 \ M$ aqueous solution of phosphorous acid $(H_3PO_3)$,the volume of $0.1 \ M$ aqueous $KOH$ solution required is .......... $mL$.

What is produced when $1 \ mol$ of calcium phosphide reacts with excess water?
$(Hint: Ca_3P_2 + H_2O (excess) \rightarrow Ca(OH)_2 + 2PH_3)$

$0.1 \ M$ solution of $KI$ reacts with excess of $H_2SO_4$ and $KIO_3$ solution. According to the equation $5I^{-} + IO_3^{-} + 6H^{+} \rightarrow 3I_2 + 3H_2O$. Identify the correct statements $:$
$(A)$ $200 \ mL$ of $KI$ solution reacts with $0.004 \ mol$ of $KIO_3$.
$(B)$ $200 \ mL$ of $KI$ solution reacts with $0.006 \ mol$ of $H_2SO_4$.
$(C)$ $0.5 \ L$ of $KI$ solution produced $0.005 \ mol$ of $I_2$.
$(D)$ Equivalent weight of $KIO_3$ is equal to $\frac{\text{Molecular weight}}{5}$.
Choose the correct answer from the options given below $:$

One mole of fluorine is reacted with two moles of hot concentrated $KOH$. The products formed are $KF, H_2O$ and $O_2$. The molar ratio of $KF, H_2O$ and $O_2$, respectively is

The normality of $1 \ M$ solution of $H_3PO_4$ will be.....$N$

The concentration of a $100 \ mL$ solution containing $X \ g$ of $Na_2CO_3$ (molecular weight $= 106$) is $Y \ M$. The values of $X$ and $Y$ are respectively.