Chemical Reaction: Molarity Calculation

How can we determine the molarity of a phosphorous acid solution?

If 11.91 ml of 0.162 M ammonia solution reacts with 84.59 ml of phosphorous acid solution, what is the molarity of the phosphorous acid solution?

The molarity of the phosphorous acid solution is approximately 0.00760 M.

To determine the molarity of the phosphorous acid solution, we need to use the balanced chemical equation and the stoichiometry of the reaction between ammonia and phosphorous acid.

When it comes to determining the molarity of a solution, it involves understanding the chemical reaction and the relationship between reactants and products. In this case, the reaction between ammonia (NH3) and phosphorous acid (H3PO3) can help us calculate the molarity of the phosphorous acid solution.

The ratio of ammonia to phosphorous acid in the balanced chemical equation 3NH3 + H3PO3 -> (NH4)3PO3 is 3:1. Given the volume and molarity of the ammonia solution that reacts, we can calculate the moles of ammonia used. Using the stoichiometry of the reaction, we then determine the moles of phosphorous acid used, which is one-third of the moles of ammonia.

Once we have the moles of phosphorous acid, we can calculate the molarity of the solution by dividing the moles of solute by the volume of the solution in liters. In this case, the molarity of the phosphorous acid solution is approximately 0.00760 M.

Understanding molarity calculations and stoichiometry in chemical reactions is essential for determining the concentration of solutions accurately. By following the steps outlined in this example, you can confidently calculate the molarity of various solutions in chemistry.