Oxidation state of hydrogen in compound $X$ is -1 and in compound $Y$ is $+1 . X$ and $Y$ are respectively

Observe the following reactions (not balanced)

$ \begin{aligned} & \mathrm{BF}_3+\mathrm{LiAlH}_4 \xrightarrow{\left(\mathrm{C}_2 \mathrm{H}_5\right)_2 \mathrm{O}} X+\mathrm{LiF}+\mathrm{AlF}_3{ }^{-} \\ & X+\mathrm{NaH} \longrightarrow Y \end{aligned} $

The incorrect statement about $Y$ is

The hydrides of which group elements of the periodic table form electron precise hydrides?

Identify the correct statements about the hydrides.

I. In saline hydrides oxidation state of hydrogen is +1 .

II. La H is an example of interstitial hydride.

III. $\mathrm{NH}_3, \mathrm{H}_2 \mathrm{O}$ have the tendency to form hydrogen bonds.

IV. Electrolysis of molten sodium hydride liberates $\mathrm{H}_2$ gas at cathode.

$ \mathrm{CaC}_2+2 \mathrm{D}_2 \mathrm{O} \longrightarrow " P^{\prime \prime}+\mathrm{Ca}(\mathrm{OD})_2 $

In the above reaction, product " $P$ " is

Deionised water is obtained by passing hard water through

The correct statements among the following are

(A) $\mathrm{BeH}_2$ and $\mathrm{MgH}_2$ are polymeric in nature.

(B) LiH is unreactive to oxygen, at moderate temperatures.

(C) $\mathrm{BeH}_2$ and $\mathrm{MgH}_2$ possesses significant covalent character.

(D) The stability of alkali hydrides follows the order $\mathrm{LiH}<\mathrm{NaH}< \mathrm{KH}<\mathrm{RbH}<\mathrm{CsH}$.

The freezing point of heavy water at 1 atm pressure is

The most effective water softening method is

On passing electric current over molten ionic hydrides of $s$-block elements,

Dihydrogen can be prepared by which of the following reactions.

(I) Reaction of granulated Zn with dil. HCl

(II) Reaction of Zn with $a q . \mathrm{NaOH}$

(III) By heating calcium hydrogen carbonate

With reference to the redox properties of hydrogen peroxide $\left(\mathrm{H}_2 \mathrm{O}_2\right)$, which of these reactions are feasible?

(i) $2 \mathrm{Fe}^{2+} 2 \mathrm{H}^{+}+\mathrm{H}_2 \mathrm{O}_2 \longrightarrow 2 \mathrm{Fe}^{3+}+2 \mathrm{H}_2 \mathrm{O}$

(ii) $2 \mathrm{MnO}_4^{-}+6 \mathrm{H}^{+}+5 \mathrm{H}_2 \mathrm{O}_2 \longrightarrow 2 \mathrm{Mn}^{2+}+8 \mathrm{H}_2 \mathrm{O}+5 \mathrm{O}_2$

(iii) $2 \mathrm{Fe}^{2+}+\mathrm{H}_2 \mathrm{O}_2 \longrightarrow 2 \mathrm{Fe}^{3+}+2 \mathrm{OH}^{-}$

(iv) $2 \mathrm{MnO}_4^{-}+3 \mathrm{H}_2 \mathrm{O}_2 \longrightarrow 2 \mathrm{MnO}_2+2 \mathrm{H}_2 \mathrm{O} +3 \mathrm{O}_2+2 \mathrm{OH}^{-} $

Which among the following is/are primary component(s) of the synthesis gas?

What is the $\%$ strength of 22.4 volume of $\mathrm{H}_2 \mathrm{O}_2$ solution?

Hard water contains ion of