The cell potential for the given cell at 298 K

Pt| H₂ (g, 1 bar) | H⁺ (aq) || Cu²⁺ (aq) | Cu(s)

is 0.31 V. The pH of the acidic solution is found to be 3, whereas the concentration of Cu²⁺ is 10^$$-$$x M. The value of x is ___________.

(Given : $$E_{C{u^{2 + }}/Cu}^\Theta $$ = 0.34 V and $${{2.303\,RT} \over F}$$ = 0.06 V)

The equation

k = (6.5 $$\times$$ 10¹²s^$$-$$1)e^{$$-$$26000K/T}

is followed for the decomposition of compound A. The activation energy for the reaction is ________ kJ mol^$$-$$1. [nearest integer]

(Given : R = 8.314 J K^$$-$$1 mol^$$-$$1)

Spin only magnetic moment of [MnBr₆]^4$$-$$ is _________ B.M. (round off to the closest integer)

For the reaction given below :

CoCl₃ . xNH₃ + AgNO₃ (aq) $$\to$$

If two equivalents of AgCl precipitate out, then the value of x will be _____________.