Chemistry dilution

Question

 student dilutes 50.0 mL of a 0.10 mol/L solution of HCl to 0.010 mol/L by adding water. Which statement is true?

Select one:

a. 

The volume of the solution remains the same.

b. 

The total amount of solute decreases.

c. 

The volume of the solvent remain the same.

d. 

The total amount of solute remain the same.

Answer 1

If the concentration of the solution is 0,10 mol/liter and there is 0.050 liters of it (which is 50 mL) then the amount of the solute is (0.10)(0.050) = 0.005 moles of solute. This, essentially, is the count of the number of atoms of the solute that is in the solution. When you add water to dilute it, there will still be 0.005 moles of the solute, just more water, resulting in a less concentrated solution, but the number of atoms of the solute is still the same, in other words, answer d is correct - the total amount of solute remains the same.