When `NaNO_(3)` is heated in a closed vessel, oxygen is liberated and `NaNO_(2)` is left behind. At equilibrium

Options

A. adding of `NaNO_(2)` favours reverse reaction
B. adding of `NaNO_(3)` favours forward reaction
C. increasing temperature favours forward reaction
D. increasing pressure favours reverse reaction

Explanation

`NaNO_(3)(s) rarr NaNO_(2)(s) + 1/2 O_(2) (g), DeltaH > 0`
`NaNO_(3)` and `NaNO_(2)` are in solid state, changing their amount has no effect on equilibrium. Increasing temperature favours forward reaction. Also, increasing pressure will favour backward reaction in which some `O_(2)(g)` will combine with `NaNO_(2)` forming `NaNO_(3)` .