Question

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

7.3g HCl in 100ml solution

Answer 1

Given:

Weight in grams = 7.3g

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

Molecular mass of HCl = 1 + 35.4 = 36.4 g/mol

Concentration in `"g"/"L" = (7.3"g")/(0.1"L")`

Concentration in g/L = 73g/L

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

= `(7.3"g")/(34.5  "g/mol")`

= 0.2 mol

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

Concentration in `"mol"/"L" = (0.2  "mole")/(0.1 "L")`

Concentration in mol/L = 2mol/L

Thus, Concentration in g/L is 73g/L and Concentration in mol/L is 2mol/L.