1.0 mol of monoatomic ideal gas is expanded from state 1 to state 2 as shown in the figure. The magnitude of the work done for the expansion of gas from state 1 to state 2 at 300 K is ____________ J. (Nearest integer)

(Given : R = 8.3 J K^$$-$$1 mol^$$-$$1, ln10 = 2.3, log2 = 0.30)

For the reaction P $$\to$$ B, the values of frequency factor A and activation energy E_A are 4 $$\times$$ 10¹³ s^$$-$$1 and 8.3 kJ mol^$$-$$1 respectively. If the reaction is of first order, the temperature at which the rate constant is 2 $$\times$$ 10^$$-$$6 s^$$-$$1 is _____________ $$\times$$ 10^$$-$$1 K.

(Given : ln 10 = 2.3, R = 8.3 J K^$$-$$1 mol^$$-$$1, log2 = 0.30)

100 mL of 0.3 M acetic acid is shaken with 0.8 g of wood charcoal. The final concentration of acetic acid in the solution after adsorption is 0.125 M. The mass of acetic acid adsorbed per gram of carbon is _____________ $$\times$$ 10^$$-$$4 g.

(Given : Molar mass of acetic acid = 60 g mol^$$-$$1)

In the following brown complex, the oxidation state of iron is +_____________.

$${[Fe{({H_2}O)_6}]^{2 + }} + NO \to \mathop {{{[Fe{{({H_2}O)}_5}(NO)]}^{2 + }}}\limits_{\text{Brown complex}} + {H_2}O$$