Presence of phosphoric acid or glycerine or acetanilide retards the decomposition of H₂O₂ .This is an example of:

• Positive catalysis.

• Negative catalysis.

• Auto catalysis.

• Induced catalysis.

For binary hydrides of formula M x n the value of n can be fractional for:

• salt like hydrides

• interstitial hydrides

• covalent hydrides

• polymeric hydrides

263.

The reaction of HBr with  in the presence of peroxide will give

• 

• 

• 

• CH₃CH₂CH₂CH₂Br

Hardness of water is due to presence of salts of:

• Na⁺ and K⁺

• Ca²⁺ and Mg²⁺

• Ca²⁺ and K⁺

• Ca²⁺ and Na⁺

H₂O is liquid while H₂S is a gas due to

• covalent bonding

• molecular attraction

• H-bonding

• both H-bonding and molecular attraction

Hydrogen peroxide when added to a solution of potassium permangnate acidified with sulphuric acid:

• Acts as an oxidising agent

• Acts as a reducing agent

• Forms water only

• Forms water only

The oxide that gives H₂O₂ on treatment with dilute acid is

• PbO₂

• MnO₂

• Na₂O₂

• TiO₂

The molarity of pure water is:

• 100

• 55.6

• 18

• 5.56

Which of the following reactions depicts the reducing action of H₂O₂ ?

• C₆H₆ + H₂O₂ $\to$ C₆H₅OH + H₂O

• 2I^- + 2H⁺ + H₂O₂ $\to$ I₂ + H₂O

• 2Mn${\mathrm{O}}_4^{-}$ + 6H⁺ +5H₂O₂ $\to$2Mn²⁺ + 5O₂ + 8H₂O

• PbS + 4H₂O₂ $\to$ PbSO₄ + 4H₂O

The density of SO₂ at STP is 2.86 kg m³. Its density at 819°C and 2 atmospheres is:

• 0.715 kg m^-3

• 1.43 kg m^-3

• 2.86 kg m^-3

• 4.26 kg m^-3