Percent Composition

Question

Calculate the percent composition of each element, by mass, in Na2CO3*10H2O

Answer 1

Look up in your chemistry book the atomic weights of Na, C, O, and H. 

 

W = molecular weight = 2(Na) + 1(C) + 13(O) + 20(H)

 

% of Na = 100 [2(Na)] / W

 

% of C = 100 [1(C)] / W

 

% of O = 100 [13(O)] / W

 

% of H = 100 [20(H)] / W

 

You do the calculations.