The S-block Elements

On combustion of $\mathrm{L}\mathrm{i},\mathrm{N}\mathrm{a}$ and $\mathrm{K}$ in excess of air, the major oxides formed, respectively, are:

Statement I: An alloy of lithium and magnesium is used to make aircraft plates.

Statement II: The magnesium ions are important for cell-membrane integrity.

In the light the above statements, choose the correct answer from the options given below

The products obtained during treatment of hard water using Clark's method are:

Lithium nitrate and sodium nitrate, when heated separately, respectively, give:

The reaction of zinc with excess of aqueous alkali, evolves hydrogen gas and gives:

10.4. Salt of which alkaline earth metals do not impart colour to a non-luminous flame.

(a) Ca (b) Mg (c) Be (d) Ba

10.3. Which of the following is not a peroxide?
(a) KO₂                 (b) CrO₅              (c) Na₂O₂            (d) BaO₂

10.2. In the Solvay process
(a) An ammoniacal brine solution is carbonated with CO₂, forming NaHCO₃ which on decomposition at 150°C produces Na₂CO₃
(b) A sodium amalgam reacts with water to produce NaOH which gives Na₂CO₃ on reacting with CO₂
(c) A brine solution is made to react with BaCO₃ to produce Na₂CO₃
(d) All of the above

10.1. Lithium shows a diagonal relationship with
(a) Sodium (b) Silicon (c) Nitrogen (d) Magnesium

10.3. Assertion: The alkalimetals and their salts impart characteristiccolour to an oxidizing flame.

Reason: This heat from the flame excites the outermost orbitalelectron to a higher energy level. When the excitedelectron comes back to the ground state, thereis emission of radiation in the visible region ofthe spectrum.