S Block Elements - Inorganic Chemistry - Chemistry Previous Year Questions

Potassium superoxide on hydrolysis gives

Lithium nitrate on heating gives

Which of the following set of metals have strong tendency to form super oxides?

Identify the correct statements with respect to compounds of beryllium.

I. Beryllium oxide is amphoteric in nature.

II. Beryllium hydride is formed by the reaction of beryllium with hydrogen.

III. Beryllium hydride is formed by the reaction of beryllium chloride with lithium aluminium hydride.

IV. Beryllium sulpahte is the least soluble sulphate among the sulphates of alkaline earth metals.

Thermal decomposition of lithium nitrate gives

Which one of the following statements is not correct?

Assertion (A) Alkali metals and their salts impart characteristic flame colours.

Reason (R) Alkali metals have low ionisation enthalpy values. So, electron excitation is possible. The correct option among the following is

Identify the incorrect reaction from the following.

The alkali metal with lowest $E^{\circ}{ }_{M^{+} / M}(\mathrm{~V})$ is $X$ and the alkali metal with highest $E^{\circ}{ }_{M^{+} / M}(\mathrm{~V})$ is $Y$. Then $X$ and $Y$ are respectively

Assertion (A) Be and Mg do not impart any colour to the flame.

Reason (R) The electrons in them are strongly bound to get excited by flame.

Which halide of alkaline earth metals is covalent in nature and can be soluble in organic solvent, such as ethanol?

Predict the feasibility of the given reactions in aqueous solution

(i) $\mathrm{Be}(\mathrm{OH})_2+2 \mathrm{OH}^{-} \longrightarrow\left[\mathrm{Be}(\mathrm{OH})_4\right]^{2-}$

(ii) $\mathrm{Be}(\mathrm{OH})_2+2 \mathrm{H}^{+} \longrightarrow\left[\mathrm{Be}(\mathrm{OH})_4\right]^{2+}$

The correct order of melting points of the following salts is

$$\begin{array}{lll} \text { LiCl } & \text { LiF } & \text { Lil } \\ \text { I } & \text { II } & \text { III } \end{array}$$

Which of the following salts can accommodate more number of $\mathrm{H}_2 \mathrm{O}$ molecules per molecule in their halide hydrates?

Unknown inorganic compound ' $A$ ' is used for water softening. ' $A$ ' reacts with $\mathrm{Na}_2 \mathrm{CO}_3$ to generate an alkaline compound ' $B$ ' whose $\mathrm{pH}=14$. ' $A$ ' on reaction with $\mathrm{CO}_2$ gives cloudy ppt. ' $B$ ' +CaO reacts with unknown organic compound ' $C$ ' to give $\mathrm{C}_6 \mathrm{H}_6$. $A$, $B$ and $C$, respectively, are

The carbonates of alkaline earth metals decompose on heating to give

I. $\mathrm{CO}_2$

II. Metal oxide

III. $\mathrm{H}_2 \mathrm{O}$

IV. CO

What is the increasing order of hydration enthalpies of alkali metal ions?

Which alkali metal emits blue colour light in flame test?

Which of the following statement(s) are correct, when alkali metals burn in the presence of oxygen?

I. Lithium forms monoxide

II. Sodium forms peroxide

III. Potassium, rubidium and cesium forms superoxide