Question

Con.hno3 is 63% hno3 by mass and a density of 1.4g/ml .how many ml of this solution are required to prepare 250 ml of 1.20 ml of 1.20 M hno3 solution.

Answer 1

250ml of 1.2M solution contains
250/1000 x 1.2 = 0.3 moles of HNO3
Molar mass of HNO3 = 1 + 14 + 16x3 = 63 g/mol
0.3 moles of HNO3 has a mass of = 0.3 x 63 = 18.8 g
The original solution has a density of 1.4 g/ml
63% of this mass is that of HNO3
Mass of HNO3 in 1 ml of the original solution = 63/100 x 1
= 0.63g
The volume of the solution that will contain 18.8g = 18.8/0.63 = 29.84 ml
Therefore, 29.84 ml of the original solution will be required to make 250ml of 1.20M HNO3 solution