Question

What is the concentration of a 450 mL solution made by dissolving 25 grams of NaCl in to water?

Answer 1

Quantity of NaCl =25 gm

Moles of NaCl=$\dfrac{weight}{molar mass}=\dfrac{25}{58.44}=0.42 moles$

Now:

Concentration=$\dfrac{moles}{volume(ml)}\times1000$

$=\dfrac{0.42}{450}\times1000=0.934$ moles per ml