Equilibrium is said to be attained in reversible reaction when

Equilibrium is attained in a reversible reaction when the rates of the forward and backward reactions are equal. This means that the reaction is still ongoing, but the concentrations of the reactants and products have reached a constant state where there is no net change in the concentrations of the reactants and products over time. Think of it like a tug-of-war between the reactants and products. At first, the reactants are winning, and the reaction proceeds in the forward direction, forming products. But as the products build up, they start to pull back in the opposite direction, and the reaction starts to go in reverse. Eventually, the pull from the reactants and products becomes balanced, and the reaction reaches a point where there is no net movement in either direction. So, when the forward and backward rates are equal, the reaction is said to be at equilibrium, and the concentrations of the reactants and products remain constant over time. Note that this does not mean that all the reactants have been used up or all the products have been formed, as the reaction is ongoing but in a state of balance.