A solution of sodium thiosulphate on addition of few drops of ferric chloride gives violet colour due to the formation of

• Na₂S₄O₆

• Fe₂(SO₄)₃

• Fe₂(S₂O₃)₃

• Fe₂(S₂O₃)₂

The chemical which is used for plastering the broken bones is

• (CaSO₄)₂H₂O

• MgSO₄·7H₂O

• FeSO₄·7H₂O

• CuSO₄·5H₂O

Solution of sodium thiosulphate in photography works as

• to shine film

• to develop film

• to dissolve silver bromide

• to change negative into positive

Which of the following is an organometallic compound?

• Lithium methoxide

• Lithium acetate

• Lithium dimethylamine

• Methyl lithium

145.

Arrange Na⁺, Mg⁺ and Al³⁺ in increasing order of energy of hydration.

• Na⁺ < Mg⁺ < Al³⁺

•  Al³⁺<  Mg⁺ < Na⁺

• Al³⁺ < Na⁺ < Mg²⁺

• Mg²⁺< Al³⁺ < Na⁺

Iron pipes, lying in acidic soil, are often attached to the blocks of magnesium for their protection from rusting, because magnesium

• is lighter than iron

• is readily converted into positive ion

• forms a corrosion-resistant alloy with iron

• prevents air from reaching the surface of iron

Which one of K, I, Cl and Li will display the highest first ionisation energy?

• K

• I

• Cl

• Li

You may have noticed that chicken-egg is very strong along its long axis so much so that it does not break even when pressed very hard. Which of the following is the main constituent of egg-shell?

• CaSO₄·2H₂O

• CaSO₄·1/2H₂O

• CaSiO₃

• CaCO₃

The number of sodium atoms in 2 moles of sodium ferrocyanide is

• 12 × 10²³

• 26 × 10²³

• 34 × 10²³

• 48 × 10²³

Nuclear attraction is often the deciding control factor for the association of neutral molecules to a given metal ion. Which one of the following represents the correct order of stability of the ions?

[Be(H₂O)₄]²⁺, [Mg(H₂O)₄]²⁺, [Ca(H₂O)₄]²⁺ and [Sr(H₂O)₄]²⁺ ?

• [Be(H₂O)₄]²⁺ > [Sr(H₂O)₄]²⁺> [Mg(H₂O)₄]²⁺ > [Ca(H₂O)₄]²⁺

• [Ca(H₂O)₄]²⁺> [Mg(H₂O)₄]²⁺ > Be(H₂O)₄]²⁺  > [Sr(H₂O)₄]²⁺

• [Sr(H₂O)₄]²⁺ > [Ca(H₂O)₄]²⁺> [Mg(H₂O)₄]²⁺ > Be(H₂O)₄]²⁺

• [Be(H₂O)₄]²⁺> [Mg(H₂O)₄]²⁺ >  [Ca(H₂O)₄]²⁺ > [Sr(H₂O)₄]²⁺