In order to make 159 ml of a 0.135 M benzoic acid solution, what mass of benzoic acid (C7H6O2) is required?

Explanation:

159 mL of .135 M benzoic acid will contain

.159 x .135 = .021465 moles of benzoic acid.

Molecular weight of benzoic acid = 122 gm

grams of .021465 moles = 122 x .021465 = 2.6 grams .

So 2.6 grams of benzoic acid will be required .

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