Salt is added to water and the mixture is stirred until no more salt dissolves. some solid salt does not dissolve and settles to the bottom of the beaker, as shown in the figure below. what happens as the water is allowed to evaporate until the volume of solution is half the original volume? assume the temperature remains constant.

The final concentration of salt in the solution will be two times of its initial concentration.

Explanation:

According to dilution formula:  

VC = constant  

Where,

V = Volume of solution  

C = concentration of salt in the solution  

So,  

                          V1C1 = V2C2       ………. (i)

After evaporation of water the volume of solution becomes half so,

                              V2 = V1/2        ………… (ii)  

Put equation (ii) in equation (i),

                           V1C1 = (V1/2)C2

                               C1 = C2/2

                              2C1 = C2           ...……… (iii)

Equation (iii) shows that the final concentration of salt in the solution will be two times of its initial concentration.