Answer
Ca = 34.5% $\qquad$ Si = 24.2%$\qquad$O = 41.3%
Work Step by Step
$\qquad$To find the percent composition of CaSiO₃, First we have to find its molecular weight.
Molar masses of Calcium, Silicon and Oxygen are:
$\qquad$$Ca = 40.1 g/mol $ $\qquad$ $ Si = 28.1 g/mol $ $\qquad$ $ O = 16.0 g/mol$
So,
$\qquad$The molecular weight of $ CaSiO₃ =[ 40.1 g/mol+ 28.1 g/mol + (3)16.0 g/mol ]= 116.2 g/mol$
Now the percent composition of each element is :
% Ca= [40.1g/mol $\times$$\left ( \frac{1 molCa }{116.2g} \right )$] $\times$ 100 = 34.5% Ca
% Si =[ 28.1g/mol $\times$$\left ( \frac{1 molSi }{116.2g} \right )$ ] $\times$ 100 = 24.2% Si
% O = [16.0g/mol $\times$$\left ( \frac{1 molO }{116.2g} \right )$ ] $\times$ 100= 41.3% O
So The percent composition of CaSiO₃ is found to be 34.5% Calcium 24.2% Silicon and 41.3% Oxygen.
