The molarity of pure water is

• 18

• 5.56

• 55.6

• 100

The hydration energy of Mg²⁺ ions is higher than that of

• Al³⁺

• Be²⁺

• Na⁺

• None of these

213.

A sample of gasoline contain 81% octane and 19% n-heptane. Its octane, number will be

• 19

• 81

• 100

• 62

The metal X is prepared by the electrolysis of fused chloride. It reacts with hydrogen to forma colourless solid from which hydrogen is released on treatment with water. The metal is

• Al

• Ca

• Cu

• Zn

Which is the correct statement?

• Hydrogen peroxide can oxidise permanganate ion.

• Permanganate ion can oxidise manganous ion.

• Manganate ion is more stable than permanganate ion.

• Permanganate ion cannot be reduced to manganate ion

Water is a

• amphoteric acid

• aprotic solvent

• protophobic solvent

• protophilic solvent

Alum is a water purifier because it

• coagulates the impurities

• softens hard water

• gives taste

• destroys the pathogenic bacteria

A commercial sample of hydrogen peroxide is labelled as is volume. Its percentage strength is nearly

• 1%

• 3%

• 10%

• 90%

The maximum number of hydrogen bonds that a molecule of water can have is

• 1

• 2

• 3

• 4

In the reaction, 2FeSO₄ + H₂SO₄ + H₂O₂ → Fe₂(SO₄)₃ + 2H₂O the oxidising agent is

• FeSO₄

• H₂SO₄

• H₂O₂

• methyl cyclopentane