Question

A solution contains one or more of the following ions: Ag , Ca2 , and Co2 . Lithium bromide is added to the solution and no precipitate forms. An excess of lithium sulfate is then added to the solution and a precipitate forms. The precipitate is filtered off and lithium phosphate is added to the remaining solution, producing a precipitate. Which ions are present in the original solution

Answer 1

`Ca^(2+) and Co^(2+)`

Step-by-step explanation:

Given:

A solution contains one or more of the following ions such as Ag,
`Ca_2` and
`Co_2`

Here the Lithium bromide is added to the solution and no precipitate forms

Solution:

Since with LiBr no precipitation takes place therefore Ag+ is absent

Here on adding
`Li_2SO_4` to it precipitation takes place.

Precipitate is as follows,

`Ca^(2+)(aq)+SO_4^2^-(aq)----->CASO_4(s)`

Thus,

`Ca^2^+` is present

When
`Li_3PO_4` is added again precipitation takes place.

Therefore the reaction is as follows,

`Co^2^+(aq)+PO_4^3^-(aq)------>Co_3(PO_4)_2(s)`

Therefore,

`Ca^(2+) and Co^(2+)` are present in the solution