Ncert Exercises & Solutions

An incorrect statement about equilibrium among the following is:

1.	In equilibrium mixture of ice and water kept in perfectly insulated flask, the mass of ice and water does not change with time.
2.	The intensity of the red colour increases when oxalic acid is added to a solution containing iron (III) nitrate and potassium thiocyanate.
3.	On the addition of a catalyst, the equilibrium constant value is not affected.
4.	The equilibrium constant for a reaction with a negative ∆H value decreases as the temperature increases.

Hint: Use the basic concept of equilibrium.

In the reaction,

{Fe}^{3 +}

+

{SCN}^{-}

⇌

{[Fe (SCN)]}^{2 +} (Red)

When oxalic acid is added it combines with Fe³⁺ ions, then, equilibrium shifts towards backward direction and intensity of

red colour decreases.