The substance which is dissolved in a solution is called:
solvent
colloids
solute
precipitant

The substance which is dissolved in a solution is called solute.

Explanation:

Solution is made up two parts:

1) Solute : The substance which is dissolves in a solvent to give a solution.

2) Solvent : The liquid substance in which solute is dissolved is known as solvent.

                             Solution = Solute + Solvent

For example : Salt as solute and water as solvent in salt solution.

if the concentration of products is decreased, the equilibrium will shift toward the products). add an inert gas (one that is not involved in the reaction) to the constant-volume reaction mixture: this will increase the total pressure of the system, but will have no effect on the equilibrium condition.

explanation:

the answers would be

the first one and the second one