Question

How many grams of calcium phosphate can be produced when 78.5 grams of calcium hydroxide reacts with excess phosphoric acid?

Answer 1

https://vcsohio.brainhoney.com/MathML/Image.ashx?data=2%20H_3Po_4%20%2B%203%20Ca(OH)_2%20%3D%20Ca_3(Po_4)_2%20%2B%206%20H_2O

Balanced equation

Answer 2

@Trinity_haha

Answer 3

I'm gonna go ahead and assume you meant reacts with excess Phosphoric acid (H3PO4)?...
(if you actually meant phosphorous acid its the same procedure, but a slightly different eqn.)


3 Ca(OH)2 + 2 H3PO4 ----> Ca3(PO4)2 + 6 H2O

Ca(OH)2 ---Molar Mass = 74 g/mol

Moles of Ca(OH)2 used:
x = ( 78.5 g / 74 g/mol ) = 1.060 mol

The ratio of stoichiometric coefficients of calcium hydroxide to calcium phosphate in the eqn. is 3 : 1.

Therefore the moles of Ca3(PO4)2 produced is:
y = (1.060 mol / 3) = 0.3533 mol

The molar mass of calcium phosphate is 310 g/mol

Therefore the mass produced is:
z = (0.3533 mol * 310 g/mol) = 109.52 grams


Therefore, number of grams of calcium phosphate produced is: 109.52 g

Answer 4

i think....

Answer 5

So after we balance the equation, we find the molar masses of 3 Ca(OH)2. Why this one?

Answer 6

i honestly have no clue.. i asked one of the people i fan to help me with the whole equation. i knew how to start it and she gave me this^^

Answer 7

ah. So any questions I ask may or may not be answered correctly?

Answer 8

i asked @ganeshie8 for the help

Answer 9

I think I can take it from here then. Thank you for the help :)