How can an unsaturated solution of a solid be made saturated?
a. increasing the temperature of the solvent
b. decreasing the temperature of the solvent
c. stirring the solution
d. removing solute

Option (b) is the correct answer.

Explanation:

A solution in which concentration of solute is lower than the equilibrium solubility is called an unsaturated solution.

Whereas a solution in which no more solute can be dissolved is known as a saturated solution.

Since solubility is proportional to temperature, therefore, decreasing the temperature will decrease the solubility. As a result, the solution will become saturated as on decreasing the temperature no more solute is soluble in the solution.

lithosphere and asthenosphere

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.