Question

Excess aqueous NaI was added to 50 mL of

aqueous CuNO3 solution, and 16.1 g of CuI
precipitate was formed. What was the molar concentration of CuNO3 in the original
solution?

Answer 1

The molarity of the solution is 1.69M.

Step-by-step explanation:

The reaction between the two reactants are:

CuNO₃+ NaI = CuI +NaNO₃.

So, 1 mole of CuNO₃ or copper nitrate produces 1 mole of CuI or Copper iodide.

Molecular weight of copper iodide =
`63.5 + 126.9`= 190.4.

So, moles of copper iodide produced here is =
`(16.1)/(190.4)`= 0.08.

So, moles of copper nitrate that was present in the solution = 0.08.

Amount of solution used = 50ml.

So, in 50ml or solution, moles of copper nitrate present = 0.08 moles.

So, in 1 liter of solution, moles of copper nitrate present = 1.69 moles.

So, the molarity of the solution is 1.69M.