Question

Base is added to a solution containing Ca+2, Na+ and K+ and a precipitate forms. What is the chemical formula of the precipitate? (use parentheses where appropriate and regular sized text as sub- and super-scripts; e.g. Al2(SO4)3 would be written Al2(SO4)3)

Answer 1

Insoluble

1. CaCr2O7

2. CaCO3

3. Ca3(PO4)2

Slightly Soluble

4. Ca(OH)2

5. CaO

6. CaSO4

Step-by-step explanation:

all the the salts above are insoluble and slightly soluble in water and so forms precipitate.

Answer 2

Answer: Ca(OH)2

Step-by-step explanation:

When a base is added to the solution, the hydroxides of the ions form.

Since NaOH and KOH are greatly soluble in water they are readily dissolved to produce a higher concentration of OH-.

Calcium Hydroxide is not very soluble in water and will appear as a precipate.

Ca(OH)2 (s) -----> Ca2+(aq) + 2OH (aq)

The higher concentration of OH- ions will force the reaction to the left and more solid Ca(OH)2 will produce as precipitate.

The Chemical formula of the precipitate is Ca(OH)2.