Question

Be sure to answer all parts.

Calculate the percent composition by mass (to 4 significant figures) of all the elements in calcium
phosphate (Ca3(PO4)2), a major component of bone.
% Ca
%P
% 0​

Answer 1

38.7%

41.3%

20%

Step-by-step explanation:

The percentage composition helps to know the what percent of the total mass of a compound is made up of each of the constituent elements or groups.

To solve this problem:

• find the formula mass by adding the atomic masses of the atoms that makes up the compound.
• place the mass contribution of the element or group to the formula mas and multiply by 100;

Compound:

Ca₃(PO₄)₂

Formula mass = 3(40) + 2[31 + 4(16)]

= 120 + 2(95)

= 120 + 190

= 310

%C =
`(3(40))/(310)` x 100 = 38.7%

%P =
`(8(16))/(310)` x 100 = 41.3%

%O =
`(2(31))/(310)` x 200 = 20%