The s-Block Elements

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-

Magnesium powder burns in air to give:

• Mg (NO₃)₂ and Mg₃N₂

• MgO and Mg₃N₂

• MgO only

• MgO and Mg(NO₃)₂

A hydrated solid X on heating initially gives a monohydrated compound X,Y upon heating above 373 K leads to an anhydrous white powder Z , X and Z respectively are :

• Baking soda and dead burnt plaster.

• Baking soda and soda ash

• Washing soda and dead burnt plaster

• Washing soda and soda ash

The correct statements among (a) to (d) are:

a) Saline hydrides produce H₂ gas when reacted with H₂O

b) Reaction of LiAlH₄ with BF₃ leads to B₂H₆

c) PH₃ and CH₄ are electrons- rich and electron- precise hydrides, respectively.

d) HF and CH₄ are called as molecular hydrides.

• a, b, c and d

• a, b and c only

• a, c and d only

• c and d only