It has been found that for a chemical reaction with rise in temperature by 9 K the rate constant gets doubled. Assuming a reaction to be occurring at 300 K, the value of activation energy is found to be ____________ kJ mol^$$-$$1. [nearest integer]

(Given ln10 = 2.3, R = 8.3 J K^$$-$$1 mol^$$-$$1, log 2 = 0.30)

0.25 g of an organic compound containing chlorine gave 0.40 g of silver chloride in Carius estimation. The percentage of chlorine present in the compound is ___________. [in nearest integer]

(Given : Molar mass of Ag is 108 g mol^$$-$$1 and that of Cl is 35.5 g mol^$$-$$1)

The number of points of intersection of

$$|z - (4 + 3i)| = 2$$ and $$|z| + |z - 4| = 6$$, z $$\in$$ C, is :

If a₁, a₂, a₃ ...... and b₁, b₂, b₃ ....... are A.P., and a₁ = 2, a₁₀ = 3, a₁b₁ = 1 = a₁₀b₁₀, then a₄ b₄ is equal to -