Which of the following statements is incorrect?

Which of the following statements is incorrect?

(i) In equilibrium mixture of ice and water kept in perfectly insulated flask

mass of ice and water does not change with time.

(ii) The intensity of red colour increases when oxalic acid is added to a

solution containing iron (III) nitrate and potassium thiocyanate.

(iii) On addition of the catalyst, the equilibrium constant value is not affected.

(iv) The equilibrium constant for a reaction with negative ∆H value decreases

as the temperature increases.