Question

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

3g CH₃COOH in 100ml solution

Answer 1

Given: 

Weight in grams = 3g

Volume in litres = 100mL = 0.1L (1mL = 1/1000L)

Molecular mass of CH₃COOH = 12 + 3 × 1 + 12 + 16 + 16 + 1 = 60 g/mol

Concentration in `"g"/"L" = (3"g")/(0.1"L")`

Concentration in = 30 g/L

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

= `(3"g")/(60  "g/mol")`

= 0.05 mol

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

Concentration in `"mol"/"L" = (0.05  "mole")/(0.01 "L")`

Concentration in mol/L = 0.05 mol/L

Thus, Concentration in g/L is 30g/L and Concentration in mol/L is 0.05mol/L.