Question

Concentrated h2so4 is 98 by mass and has density 1.84gcm3 what volume of the conc. Acid required to make 5.00litre of 0.5 M h2s04 sol.

Answer 1

given,

molar mass of sulphuric acid, H2SO4 = 98 g/mol

density of sulphuric acid = 1.84 g/cm³

volume of solution = 5 Litre

concentration of H2SO4 = 0.5M

we know, number of mole of solute = concentration of solute in solution × volume of solution

so, number of mole of sulphuric acid = 0.5M × 5Litre = 2.5 moles.

now mole = given mass / molecular mass

or, 2.5 = given mass/98 g/mol

or, given mass = 2.5 × 98 = 245 g

now volume of sulphuric acid = mass of sulphuric acid/density of sulphuric acid

= 245/1.84 cm³

= 133.15 cm³

Answer 2

Answer:

Concentrated H₂SO₄ is 98% by mass and has density 1.84gcm3, what volume of the concentrated acid is required to make 5.00litre of 0.5 M H₂SO₄ solution?

The amount of concentrated acid required is 140.9716 cm³

Explanation:

The molarity of the final  H₂SO₄ solution is 0.5M and the volume is 5 litres

We can get the moles of the H₂SO₄ used in this dilution.

Molarity = Moles/ volume in litres

Moles = Molarity × Volume in Litres

∴ Moles of the H₂SO₄ = 0.5 M × 5 liters

                                       = 2.5 moles of the H₂SO₄

Note: the moles of H₂SO₄ in the final solution is the same as that in the original solution ( only the water volume changes).

Therefore the moles of the H₂SO₄ in the original solution is also 2.5 moles

We know that moles = mass / molar mass

∴ We can calculate the mass of the H₂SO₄

Mass = moles × molar mass

Molar mass of H₂SO₄ = 100 g/mol

Mass of the H₂SO₄ ∴  = 2.5 moles × 100g/mol

                                     = 250 g

The mass of the H₂SO₄ is thus 250 g

Density of the H₂SO₄ is 1.84g/cm³

Therefore the volume of the H₂SO₄ in the solution is:

      =   250g / 1.84gcm⁻³ = 135.8696 cm³

We know that this mass is 98% of the original solution

Mass of the solution:

98% = 250g

∴ 100% = 250 × 100/98

             = 255.1020g

The mass of the water in the concentrated H₂SO₄ acid is

                      =  255.1020 - 250

                      = 5.1020 g

Density of water is 1 g/cm³

Therefore the volume of water = 5.1020g × 1g/cm³

                                                    = 5.1020 cm³

The total volume of the solution is:

5.1020 cm of water + 135.8696 cm³ of H₂SO₄

= 140.9716 cm³

Therefore the concentrated acid required is 140.9716 cm³