Question

Write down the concentration of the following solution in g/L and mol/L. 

4.9 g H₂SO₄ in 200ml solution

Answer 1

Given: 

Weight in grams = 4.9g

Volume in litres = 200mL = 0.2L (1mL = 1/1000L)

Molecular mass of H₂SO₄ = 2 × 1 + 32 + 4 × 16 = 98 g/mol

Concentration in `"g"/"L" = (4.9"g")/(0.2"L")`

Concentration in = 24.5 g/L

No. of Moles(n) = `"weight"/"molecular mass"`

= `(4.9"g")/(98  "g/mol")`

= 0.05 mol

Concentration in `"mol"/"L" = "no. of mole"/"Volume in L"`

Concentration in `"mol"/"L" = (0.05  "mole")/(0.02 "L")`

Concentration in mol/L = 0.25 mol/L

Thus, Concentration in g/L is 24.5 g/L and Concentration in mol/L is 0.25 mol/L.