15 mL of aqueous solution of Fe²⁺ in acidic medium completely reacted with 20 mL of 0.03 M aqueous Cr₂O$$_7^{2 - }$$. The molarity of the Fe²⁺ solution is __________ $$\times$$ 10^-2 M. (Round off to the Nearest Integer).

In the above reaction, 3.9 g of benzene on nitration gives 4.92 g of nitrobenzene. The percentage yield of nitrobenzene in the above reaction is ________%. (Round off to the Nearest Integer).

(Given atomic mass : C : 12.0 u, H : 1.0 u, O : 16.0 u, N : 14.0 u)

For a certain first order reaction 32% of the reactant is left after 570s. The rate constant of this reaction is _________ $$\times$$ 10^$$-$$3 s^$$-$$1. (Round off to the Nearest Integer). [Given : log₁₀2 = 0.301, ln10 = 2.303]

0.01 moles of a weak acid HA (K_a = 2.0 $$\times$$ 10^$$-$$6) is dissolved in 1.0 L of 0.1 M HCl solution. The degree of dissociation of HA is __________ $$\times$$ 10^$$-$$5 (Round off to the Nearest Integer).

[Neglect volume change on adding HA. Assume degree of dissociation <<1 ]