Water was added to 120g of salt, MCl2 to produce 60.0cm3 of a saturated solution at 45o C. Its solubility at 45o C is 8.0 mol dm-3. i) Calculate the mass of the salt which remain undissolved.
ii) Is the solution saturated or unsaturated or supersaturated? Give reason for your answer. (M = 24 , Cl = 35.5)

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

explanation: