# chemistry

posted by
**Lisa, Help needed!**
.

To what volume should you dilute 131 mL of an 8.20 M CuCl2 solution so that 49.0 mL of the diluted solution contains 4.53g CuCl2 ?

Chemistry...Help!! - Dr Russ, Wednesday, December 8, 2010 at 4:43am

Molar mass of CuCl2 is 134.5 g mol^-1

so solution needs to contain

4.53 g / 134.5 g mol^-1

=0.03368 mole

concentration is

0.049 L/0.03368 mole

=1.455 molar

thus we need to dilute the 8.20 M solution by a factor

8.20 M/1.455 M= 5.636

so the new total volume is

131 ml x 5.636

=738.4 ml

check on the concentration

old solution contains

131 x 8.20 mmoles = 1074 mmoles

new solution contains

1.455 x 738.4 mmole = 1074 mmole

Chemistry...Help!! - Lisa, Help needed!, Wednesday, December 8, 2010 at 1:59pm

Thank you for all the detail, but i'm still confused......so 738.4mL is the answer?