Question

What is the coefficient for H2O when the equation ? Ca(OH)2(aq) + ? H3PO4(aq) → ? Ca3(PO4)2(s) + ? H2O(ℓ) is balanced using the smallest possible integers?

Answer 1

Answer:

Coefficient of $H_{2}O$ in the balanced equation with smallest possible integer is 6.

Explanation:

Unbalanced equation: $Ca(OH)_{2}(aq.)+H_{3}PO_{4}(aq.)\rightarrow Ca_{3}(PO_{4})_{2}(s)+H_{2}O(l)$

Balance Ca: $3Ca(OH)_{2}(aq.)+H_{3}PO_{4}(aq.)\rightarrow Ca_{3}(PO_{4})_{2}(s)+H_{2}O(l)$

Balance $PO_{4}$  : $3Ca(OH)_{2}(aq.)+2H_{3}PO_{4}(aq.)\rightarrow Ca_{3}(PO_{4})_{2}(s)+H_{2}O(l)$

Balance H and O: $3Ca(OH)_{2}(aq.)+2H_{3}PO_{4}(aq.)\rightarrow Ca_{3}(PO_{4})_{2}(s)+6H_{2}O(l)$

Balanced equation: $3Ca(OH)_{2}(aq.)+2H_{3}PO_{4}(aq.)\rightarrow Ca_{3}(PO_{4})_{2}(s)+6H_{2}O(l)$

So coefficient of $H_{2}O$ in the balanced equation with smallest possible integer is 6.