.Example: How do you prepare 1.0 M of H2SO4 from concentrated sulphuric acid having %(w/w)=98%, ρ=1.84 g/mL, and Molecular weight = 98 g/mol in 1 L volume?
To prepare 1.0 M H2SO4 solution from concentrated sulphuric acid (98% w/w), you will need to follow these steps:
1. Calculate the molarity of the concentrated sulphuric acid:
Since the concentrated sulphuric acid is 98% w/w, this means that 98g of sulphuric acid is present in 100g of solution.
Given that the molecular weight of H2SO4 is 98 g/mol,
The number of moles of H2SO4 in 100g of solution = 98g/98g/mol = 1 mol
So the molarity of the concentrated sulphuric acid = 1 mol/0.1 L = 10 M
2. Determine the volume of concentrated sulphuric acid needed to make 1.0 L of 1.0 M H2SO4 solution:
Since the molarity of the concentrated sulphuric acid is 10 M and you want to prepare a 1.0 M solution, you will need to dilute it tenfold.
Therefore, the volume of concentrated sulphuric acid needed = 1.0 L/10 = 0.1 L
3. Calculate the mass of the concentrated sulphuric acid needed:
Mass of concentrated sulphuric acid needed = volume x density
= 0.1 L x 1.84 g/mL = 0.184 g
4. Dilute the concentrated sulphuric acid with water to make 1.0 L of 1.0 M H2SO4 solution:
Measure out 0.1 L of concentrated sulphuric acid and add it to a 1.0 L volumetric flask.
Then, fill the rest of the volumetric flask with water up to the 1.0 L mark.
After following these steps, you will have successfully prepared a 1.0 M H2SO4 solution from concentrated sulphuric acid.