Question

Rob is attempting to dissolve rock salt in warm water but it is a slow process. How could he most effectively increase the rate of solution of the rock salt?
A) Decrease the temperature of the water.
B) Increase the concentration of the salt.
C) Grind the rock salt into smaller pieces.
D) Agitate the rock salt and the cool water.

Answer 1

Answer:

C) Grind the rock salt into smaller pieces.

Explanation:

To dissolve rock salt we need certain amount of heat, which is provided by the warm water. Now, this warm water won't dissolve easily the rock salt, because that salt in that state as rock, it's harder, that is, the heat won't penetrate easily in to the material to dissolve it.

Now, if we grind the rock salt into smaller pieces, we'll accelerate the process, because each pieces requires less heat to be dissolved. Basically, when we do smaller pieces, we are giving the energy needed to grind that rock, and such energy won't be needed from the warm water, so the actual energy from the warm water will be focused on dissolving each small piece.

Therefore, the right answer is C.

Answer 2

C) grind the rock salt into smaller pieces