31.

If equilibrium constant for reaction 2AB A₂ + B₂ is 49, then the equilibrium constant for reaction

AB $\rightleftharpoons$ $\frac{1}{2}$A₂ + $\frac{1}{2}$B₂, will be;

• 7

• 280

• 49

• 0.01

According to Hess's law, the heat of reaction depends upon :

• initial condition of reactants

• initial and final conditions of reactants

• intermediate path of the reaction

• end conditions of reactants

A reaction is catalysed by 'X' Here 'X' :

• decreases the rate constant of reaction

• does not affect the equilibrium constant of reaction

• decreases the enthalpy of reaction

• decreases the activation energy

For a reaction; A + B  product, it was found that rate of reaction increases four times if concentration of 'A' is doubled, but the rate of reaction remains unaffected if concentration of 'B' is doubled. Hence, the rate law for reaction is :

• rate = k[A][B]

• rate = k[A]²

• rate = k [A]²[B]¹

• rate = k [A]²[B]²

The E° for half cells Fe/Fe²⁺ and Cu/Cu²⁺ are -0.44 V and +0.32 V respectively. Then :

• Cu²⁺ oxidises Fe

• Cu²⁺ oxidises Fe²⁺

• Cu oxidises Fe²⁺

• Cu reduces Fe²⁺

The iron, obtained from blast furnace is :

• pig iron

• cast iron

• wrought iron

• steel

Transition metals are related to which block ?

• 's' block

• 'p' block

• 'd' block

• none of these

The general electronic configuration of transition elements, is :

• (n-1)d^1-5 ns⁰

• (n-1)d^1-10 ns¹

• (n-1)d^1-10 ns²

• (n-1)d^1-10 ns^1-2

Which one of these, is not a colligative property ?

• vapour pressure

• osmotic pressure

• lowering in freezing point

• Elevation in boiling point

Which of the following element does not show variable valency ?

• Ni

• Zn

• Cu

• Mn