Question

The anticaking agent added to table salt is calcium metasilicate (casio3). this compound can absorb up to 2.5 times its mass in water and still remain a free-flowing powder. calculate the percent composition of casio3.

Answer 1

We are asked to calculate the percent composition of CaSiO₃ which refers to the percent of the total mass of the compound that is made up of each element. We will calculate the percent by mass of each element in the species, so we will first find the molecular weight of CaSiO₃.

Ca = 40.1 g/mol
Si = 28.1 g/mol
O = 16.0 g/mol

The total molecular weight is as follows:

[(40.1 g/mol) x 1 mol Ca] + [28.1 g/mol x 1 mol Si] + [(16 g/mol) x 3 mol O] = 116.2 g/mol

Now that we have the total mass of CaSiO₃, we can calculate the percent composition in 1 mol of CaSiO₃:

% Ca = [(40.1 g/mol x 1 mol Ca)/116.2 g] x 100% = 34.5% Ca

% Si = [(28.1 g/mol x 1 mol Si)/116.2 g] x 100% = 24.2% Si

% O = [(16 g/mol x 3 mol O)/116.2 g] x 100% = 41.3% O

The percent composition of CaSiO₃ is found to be 34.5% Ca, 24.2% Si and 41.3% O.