Question

calculat the molar concentration of ammonium-sulphate (NH4)2SO4 (molar mass 132.14 g/mol) in a solution if the sulphur concentration are found to be 10.0 microgram/gram.

Answer 1

29474, Inorganic Chemistry

Calculate the molar concentration of ammonium-sulphate (NH4)2SO4 (molar mass 132.14 g/mol) in a solution if the sulphur concentration are found to be 10.0 microgram/gram.

Solution:

In 1 mole of $(\mathrm{NH}_4)_2\mathrm{SO}_4$ contains 1 mole of sulphur (S).

If we assume that the density of solution is $1\mathrm{g/mL}$, than one litter of solution weighs $1000\mathrm{g}$.

The mass of sulphur which is contained in 1 L of solution is: $10.0 \cdot 10^{-6} \cdot 10^{3} = 0.01\mathrm{g}$.

Number of moles of sulphur per liter of solution is: $0.01/32.06 = 3.12 \cdot 10^{-4} \mathrm{mol/L}$.

As mentioned above, the molar concentration of $(\mathrm{NH}_4)_2\mathrm{SO}_4$ is $3.12 \cdot 10^{-4} \mathrm{mol/L}$.

Answer:

The molar concentration of $(\mathrm{NH}_4)_2\mathrm{SO}_4$ is $3.12 \cdot 10^{-4} \mathrm{mol/L}$.