At what change in Gibbs free energy $(\Delta G)$ does a reaction reach equilibrium?

Explain the types of physical equilibrium with examples.

Explain chemical equilibrium by giving an example of a general reaction.

For the reaction $2HI_{(g)} \rightleftharpoons H_{2(g)} + I_{2(g)}$,the equilibrium constant $K$ at room temperature is $2.85$,and at $698 \ K$ it is $1.4 \times 10^{-2}$. This indicates that:

Mark the correct statement in a reversible reaction.

For the equilibrium $A \rightleftharpoons B$,the variation of the rate of the forward $(a)$ and reverse $(b)$ reaction with time is given by: