Question

How is the reaction rate related to equilibrium?

Answer 1

In a chemical reaction, chemical equilibrium is the state where the forward and reverse reactions rates are equal. In the result of this equilibrium, the concentrations of the reactants and the products do not change. Just because the concentrations don't change doesn't mean that all chemical reactions have stopped. Exactly the opposite is the case; Chemical equilibrium is a dynamic state in which reactants are converted into products at any time, but at the precise rate at which products are converted back into reactants.

Complete step-by-step answer: It is not related, but the reaction rate of both sides of the reversible reaction is equal at equilibrium.
The reaction rate is simply the rate at which a reaction occurs, i.e., the time it takes for a given amount if the product is produced.
${\text{Reactant }} \rightleftharpoons \,\,{\text{Product}}$
The rate of the reaction can be measured from
1. Weigh the substance to see how much gas escapes (obviously this has its limits) 2. Use a gas syringe to measure the volume of gas produced
3. Measure the time it takes for a mark to disappear under an originally transparent substance (this only works when precipitation forms)
Since the equilibrium has to do with the comparison of products and reactants produced in a reversible reaction. Because the reaction goes in both directions, the products can interact with each other to form the reactants. They will continue to react back and forth until the balance is achieved. This does not mean that there are no more reactions, rather it only means that both the forward reactions (product-to-product-reactions) and the adverse reactions (product-to-reactants) occur at the same rate. So, the product/reactant quantity on both sides will remain the same.
However, we can modify when this happens to produce more product (or reagent). This is known as changing the equilibrium point, but it is not the same as changing the reaction rate. It just means that the amount of each side will remain the same in a different spot.
So, the only relation is that when a reversible reaction has reached equilibrium, the forward and backward reaction rate is the same, so that the products are produced at the same rate as they are. broken down into reactants. When this happens, it affects the product/reagent ratio.

Note: We can change the equilibrium point by adjusting the temperature and pressure. A high temperature favours the endothermic reaction, since more energy is available, while a low temperature favours the exothermic side. Likewise, high pressure will benefit the side with the least gaseous particles as they collide more strongly, while a lower pressure will move the equilibrium to the side with the least gaseous particles.