For the reaction, 2NO₂(g) $$\rightleftharpoons$$ N₂O₄(g), when $$\Delta$$S = $$-$$176.0 JK^$$-$$1 and $$\Delta$$H = $$-$$57.8 kJ mol^$$-$$1, the magnitude of $$\Delta$$G at 298 K for the reaction is ___________ kJ mol^$$-$$1. (Nearest integer)

The sum of oxidation states of two silver ions in [Ag(NH₃)₂] [Ag(CN)₂] complex is _____________.

The number of atoms in 8g of sodium is x $$\times$$ 10²³. The value of x is ____________. (Nearest integer)

[Given : N_A = 6.02 $$\times$$ 10²³ mol^$$-$$1

Atomic mass of Na = 23.0 u]

If 80 g of copper sulphate CuSO₄ . 5H₂O is dissolved in deionised water to make 5L of solution. The concentration of the copper sulphate solution is x $$\times$$ 10^$$-$$3 mol L^$$-$$1. The value of x is _____________.

[Atomic masses Cu : 63.54u, S : 32u, O : 16u, H : 1u]