Question

A solution is made by dissolving 11.3 g of calcium nitrate, Ca(NO3)2, in enough water to make exactly 500 mL of solution. Calculate the concentration (molarity) of Ca(NO3)2 in mol/L (M).


M Ca(NO3)2

Answer 1

Solution:

1.n=m/M;

M(Ca(NO3)2)=40+14×2+48×2=164 gram/mole;

2.n(Ca(NO3)2)=11.3/164=0.069 mol;

3.V(solution)=0.5 L

4.C=n/V;

C(Ca(NO3)2)=0.069/0.5=0.138 mol/L

Answer:C(Ca(NO3)2)=0.138 mol/L.