The yellow solution of $Na_2CrO_4$ changes to orange red on passing $CO_2$ gas due to the formation of:

Which reaction is not affected by a change in pressure?

In the reaction: $H_2S \rightleftharpoons 2H^{+} + S^{2-}$,when $NH_4OH$ is added,then

The equilibrium $SO_2Cl_{2(g)} \rightleftharpoons SO_{2(g)} + Cl_{2(g)}$ is attained in a closed vessel at $25 \, ^\circ C$. If an inert gas,$He$,is added at constant volume,which of the following statement$(s)$ is/are correct?

Le Chatelier's principle is applicable to which of the following?

When in any system at equilibrium state,pressure,temperature,and concentration are changed,then the equilibrium shifts in such a direction as to neutralize the effect of the change. This is known as: