Question

what is the concentration of ni2 that remains in solution?a solution of 120.0 ml of 0.200 m koh is mixed with a solution of 260.0 ml of 0.230 m niso4.

Answer 1

The molarity of the nickel left in the solution is 0.126 M.

We can see that the net ionic equation is;

`Ni^(2+)(aq) + 2OH^-(aq) -- > Ni(OH)_2(s)`

Number of moles of nickel solution = 260/1000 L * 0.230 M

= 0.0598 moles

Number of moles of hydroxide solution = 120/1000 L * 0.2 M

= 0.024 moles

If 1 mole of nickel solution reacts with 2 moles of hydroxide

x moles of nickel reacts with 0.024 moles of hydroxide

x = 0.012 moles

Moles of nickel left = 0.0598 moles - 0.012 moles

= 0.0478 moles

Molarity of the nickel left in solution = 0.0478 moles/(120 + 260)/1000 L

= 0.126 M