Calculate the molar concentration of a solution that is 50% in NaOH (w/W) and has a specific gravity of 1.52 .
Asked by buttercup
| 1st Feb, 2012,
07:03: PM
Mass of pure compound (NaOH),m= S.G X V X % composition
Where SG is specific gravity
V is volume of solution; assume it to be 1 L or 1000 ml
% composition means xg of pure compound per 100g of solution
Since NaOH is 50% by weight so, it means
28.3 % by wt NaOH maens 50 gm NaOH + 50 gm H2O = 100 gms
So, mass of NaOH in solution will be= 1.52 X 1000 X 0.50 = 760 gms NaOH/L
Now, molar mass of NaOH = 40 gm/mol
So, molar concentration of NaOH= Mass of NaOH in solution/ Molar mass
= 760 gms/40 gm/mol
= 19 mol/L = 19 M
molar concentration of NaOH = 19 M
Mass of pure compound (NaOH),m= S.G X V X % composition
Where SG is specific gravity
V is volume of solution; assume it to be 1 L or 1000 ml
% composition means xg of pure compound per 100g of solution
Since NaOH is 50% by weight so, it means
28.3 % by wt NaOH maens 50 gm NaOH + 50 gm H2O = 100 gms
So, mass of NaOH in solution will be= 1.52 X 1000 X 0.50 = 760 gms NaOH/L
Now, molar mass of NaOH = 40 gm/mol
So, molar concentration of NaOH= Mass of NaOH in solution/ Molar mass
= 760 gms/40 gm/mol
= 19 mol/L = 19 M
molar concentration of NaOH = 19 M
Answered by
| 15th Feb, 2012,
12:15: PM
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