You have 125.0mL of a solution of H3PO4, but you don't know its concentration. If you titrate the solution with a 4.56M solution of NaOH and reach the endpoint when 134.1mL of the base are added, what is the concentration of the acid?

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e