361.

Setting of plaster of Paris is

• dehydration

• oxidation with atmospheric oxygen

• combination with atmospheric CO₂

• hydration to yield another hydrate

White metal is an alloy of

• Na and Mg

• Na and Pb

• Li and Mg

• Li and Pb

Which one of the following will not give flame test?

• Ca

• Ba

• Sr

• Be

Which alkaline earth metal compound is volatile?

• Mg₃N₂

• Ca₃N₂

• Be₃N₂

• None of the equation

The set representing the right order of ionic radius is

• Li⁺ > Na⁺> Mg²⁺ > Be²⁺

• Mg²⁺ > Be²⁺> Li⁺> Na⁺

• Na⁺> Mg²⁺> Li⁺> Be⁺

• Na⁺> Li⁺> Mg²⁺> Be⁺

The element that forms stable compounds in low oxidation state is

• Mg

• Al

• Ga

• Tl

Atomic radius (pm) of Al, Si,N and F respectively is:

• 117, 143, 64, 74

• 143, 117, 74, 64

• 143, 47, 64, 74

• 64, 74, 117, 143

The correct order of hydration enthalpies of alkali metal ions is:

• Li⁺ > Na⁺ > K⁺ > Cs⁺ > Rb⁺

• Na⁺ > Li⁺ > K⁺ > Rb⁺ > Cs⁺

• Na⁺ > Li⁺ > K⁺ > Cs⁺ > Rb⁺

• Li⁺ > Na⁺ > K⁺ > Rb⁺ > Cs⁺

The covalent alkaline earth metal halide (X = Cl, Br, I) is :

• MgX₂

• BeX₂

• CaX₂

• SrX₂

The isoelectronic set of ions is :

• Li⁺, Na⁺, O^2- and F^-

• N^3-, O^2-, F^- and Na⁺

• F^-, Li⁺, Na⁺ and Mg²⁺

• N^3-,Li⁺, Mg²⁺ and O^2-