0.040mol of (NH4)2Ni(SO4)2•6H2O is dissolved in water to give 200cm3 of aqueous solution. What is the concentration, in mol dm–3, of ammonium ions?

1 Answer
May 11, 2017

Answer:

#"Concentration"="Moles of solute"/"Volume of solution"......=0.40*mol*dm^-3.#

Explanation:

#"Concentration with respect to the nickel salt"#

#=(0.040*mol)/(0.200*dm^3)=0.20*mol*dm^-3#

But given the formulation of the salt, #(NH_4)_2[Ni (SO_4)_2]*6H_2O#, there are 2 equiv of ammonium per equiv of salt. And thus #[NH_4^+]=0.40*mol*dm^-3#