Answer
$Ca_{3}(PO_{4})_{2}$+ 3$H_{2}SO_{4}$ $\longrightarrow$
3$CaSO_{4}$ +2$H_{3}PO_{4}$
Work Step by Step
The strategy requires to find the coefficient to balance the chemical equation. First look for atoms of elements that occur in only one substance on each side of equation.
Begin by balancing these atoms to get to the balanced chemical equation.
Count the atoms of each element in each side of equation, to see if they are in the same number in each side.
First we have to write the equation for this reaction. Knowing the charge for each ion, we can write:
$Ca_{3}(PO_{4})_{2}$+ $H_{2}SO_{4}$ $\longrightarrow$
$CaSO_{4}$ +$H_{3}PO_{4}$
We see that Ca atoms are not balance as there are 3 on the left and 1 on the right. Add 3 before $CaSO_{4}$
$Ca_{3}(PO_{4})_{2}$+ $H_{2}SO_{4}$ $\longrightarrow$
3$CaSO_{4}$ +$H_{3}PO_{4}$
We see that H atoms are not balanced: there are 2 on the left and 3on the right. Add 3 before $H_{2}SO_{4}$ and 2 before $H_{3}PO_{4}$ to balance atoms H:
$Ca_{3}(PO_{4})_{2}$+ 3$H_{2}SO_{4}$ $\longrightarrow$
3$CaSO_{4}$ +2$H_{3}PO_{4}$
Count the atoms of each other elements ( P,S, and O) and find our that we have balanced the equation.
