1. A solution is made by mixing 50mL of 2.0M K2HPO4 and 25mL of 2.0M KH2PO4. The solution is diluted to a final volume of 200mL. what is the pH of the final solution

The pH of the final solution is 7.15

Explanation:

50 mL of 2.0 M of and 25 mL of 2.0 M of were mixed to make a solution

Final volume of the solution after dilution = 200 mL

Final concentration of

Final concentration of

We use Hasselbach- Henderson equation:

Substituting the values:

Therfore,  the pH of the final solution is 7.15

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.