Question

If water is added to 50 ml of a 0.04M solution so that it fills a 200 mL beaker, what is the final concentration?

Answer 1

Final concentration `=` `0.01*mol*L^-1`.

Explanation:

`"Concentration"` `=` `"Moles of solute"/"Volume of solution in litres"`

`=` `(50xx10^-3*Lxx0.04*mol*L^-1)/(200xx10^-3L)`

`=` `(50xxcancel(10^-3)*cancelLxx0.04*mol*L^-1)/(200xxcancel(10^-3L))`

`=` `(1xxcancel(10^-3)*cancelLxx0.04*mol*L^-1)/(4xxcancel(10^-3L))`

`=` `0.01*mol*L^-1`