What is the concentration in moles/litre that results from diluting a 10%w/v solution of NaCl (molecular weigh

Question

What is the concentration in moles/litre that results from diluting a 10%w/v solution of NaCl (molecular weight 58.1) four fold?

Answer 1

1) grames of solute dissolved in 10% w/v is 10 grams per 100 mililiters

2) Diluting it four fold yields:

10 grams per 400 ml of solution = 2.5 grams per 100 ml = 0.25 grams per litre

3) 0.25 grames is equal to (0.25/58.1) = 0.0043 moles of NaCl

4) So, final molar concentration is 0.0043 M

That's it!

Good luck!