Adding which of the following substances will decrease the solubility of calcium chloride in water: cacl2(s) ca2+(aq) + 2 cl–(aq)?

a. sodium chloride
b. sodium fluoride
c. no right choice.

Option b. Sodium chloride.

Explanation:

Consider the dissociation equilibrium of in water:

.

By the Le Chatelier's Principle, increasing the concentration of either product will shift the equilibrium to the left. Some that was initially dissolved will precipitate out of the solution. This effect is called the common-ion effect.

For this solution, the products of dissociation are

Adding either to the solution will trigger the common-ion effect and reduce the solubility of .

In the two choices,

contains ions. It is capable of triggering the common-ion effect. However contains neither ions nor ions. It will not trigger the common-ion effect.

- "the choice that is not an indicator of a chemical change is "state of matter changes". more common than not, chemical reactions produce energy in the form of light or heat. along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid)."

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.