Question

question
what is the formula of barium phosphate?
a. $\ce{ba_{2}(po_{4})_{2}}$
b. $\ce{ba_{3}(po_{4})_{3}}$
c. $\ce{ba_{3}(po_{4})_{2}}$
d. $\ce{ba_{2}(po_{4})_{3}}$

Explanation:

Step1: Determine the charge of barium ion

Barium (\(Ba\)) is in group 2 of the periodic table, so it forms \(Ba^{2+}\) ion.

Step2: Determine the charge of phosphate ion

Phosphate ion is \(PO_{4}^{3 -}\).

Step3: Use the criss - cross method

To balance the charges, we need 3 \(Ba^{2+}\) ions (\(3\times2+=6+\)) and 2 \(PO_{4}^{3 -}\) ions (\(2\times3 - = 6-\)).
So the formula is \(Ba_{3}(PO_{4})_{2}\).

Answer:

C. \(Ba_{3}(PO_{4})_{2}\)