Use the following reaction: 3Ca(OH)2 + 2H3PO4→ Ca3(PO4)2 + 3H2O How many grams of H2O will be produced if 111.5 grams of Ca(OH)2 are reacted with excess H3PO4?

Question

show all work please! i need it in order to get credit

Answer 1

Hello, Arshi,

The equation you provided doesn;t appear to be balanced.

I get 3Ca(OH)2 + 2H3PO4→ Ca3(PO4)2 + 6H2O

I'll use mine in the calculations.

Note from the equation we get 6 moles H2O for every 3 moles Ca(OH)2, for a molar ratio of 2 H2O/Ca(OH)2

Now find the moles of Ca(OH)2 present in 111.5 grams by dividing by it's molar mass of 74.1g/mole.

111.5 g/74.1 g/mole = 1.505 moles

Multiply this by the molar ratio of 2 to find moles water (3.009 moles). Then multiply the moles by the molar mass of water (18 g/mole) to find grams H2O. I get 54.17 grams H₂O.

Bob