[akiwo]

Hello, I've never been good in quantitative chemistry and once again this kind of question seems to be a trouble for me ehh

I would be so grateful for showing the exact working.

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

[sjb]

Hello, I've never been good in quantitative chemistry and once again this kind of question seems to be a trouble for me ehh

I would be so grateful for showing the exact working.

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

Can you calculate the concentration of the overall compound?

[Hunter2]

Check how many ammonium ions you have in your compound. This you multipl by your given moles.  After that you devide through your volume and correct the units to what is requested.