Question

A student prepared 200mL of 0.01M solution of calcium phosphate, Can(PO4)2. What is the concentration of calcium in parts per million? Relative atomic masses Can =40, P =31, O =16

Answer 1

by the way calcium is Ca
Ca(PO^4)2
Ca=40, P=31, O=16
In BODMAS we deal with the ones in he bracket first
Ca (P O^4)2
40 (31 + 16*4)2
the reason why i multiplied 16 by 4 is because it is raised to the ^4
40 (64)2
In mathematics when you have a(b) it means a*b
40 (64*2)
40 (128)
the relative atomic mass is 512
but we are looking for for calcium which is 40 per million
note: when they say percent is over 100 because a cent is 100
40/512 * 1000000/1
=78125

Answer 2

Bolaji, the molecular mass of the given compound is NOT 512. The compound calcium phosphate should be written as Ca3(PO4)2, and has a mass of 310 u.
You do not multiply the masses of calcium and phosphate, this is not an algebraic equation.
You add the masses of calcium and phosphate. (3*40 + 2*95)

As for the question, I am not sure of the exact methodology and it would be best to wait for a Jiskha chemistry tutor.

Answer 3

A student prepared 200mL of 0.01M solution of calcium phosphate, Can(PO4)2. What is the concentration of calcium in parts per million? Relative atomic masses Can =40, P =31, O =16.

compound: Ca3(PO4)2, molecular mass= (40*3+2*31+8*16)=310
so the total mass of calcium in the solution is .2*.01*120=.24 grams.
the total mass of the solution is 200 ml*1g/ml (it is a dilute solution), so you have
.24gramsCalcium/200 grams. So you want parts per million?
.24e6 milliongramsCa/200grams=240000/200=1200
check my math.