**Paragraph**

Thermal decomposition of gaseous X

_{2}to gaseous X at 298 K takes place according to the following equations:

X

_{2}(g) $$\leftrightharpoons$$ 2X (g)

The standard reaction Gibbs energy, $$\Delta _rG^o$$, of this reaction is positive. At the start of the reaction, there is one mole of X

_{2}and no X. As the reaction proceeds, the number of moles of X formed is given by $$\beta$$. Thus, $$\beta _{equilibrium}$$ is the number of moles of X formed at equilibrium. The reaction is carried out at a constant total pressure of 2 bar. Consider the gases to behave ideally. (Given R = 0.083 L bar K

^{-1}mol

^{-1})

**Question**

The INCORRECT statement among the following for this reaction, is

Solubility product constants (K$$_{sp}$$) of salts of types MX, MX$$_2$$ and M$$_3$$X at temperature T are 4.0 $$\times$$ 10$$^{-8}$$, 3.2 $$\times$$ 10$$^{-14}$$ and 2.7 $$\times$$ 10$$^{-15}$$, respectively. Solubilities (mol dm$$^{-3}$$) of the salts at temperature 'T' are in the order:

2.5 mL of $$\frac{2}{5}$$M weak monoacidic base (K$$_b$$ = 1 $$\times$$ 10$$^{-12}$$ at 25$$^\circ$$C) is titrated with $$\frac{2}{15}$$M HCl in water at 25$$^\circ$$C. The concentration of H$$^+$$ at equivalence point is (K$$_w$$ = 1 $$\times$$ 10$$^{-14}$$ at 25$$^\circ$$C).

Statement 1 : For every chemical reaction at equilibrium, standard Gibbs energy of reaction is zero.

and

Statement 2 : At constant temperature and pressure, chemical reactions are spontaneous in the direction of decreasing Gibbs energy.