A 50.51g sample of a compound made from
phosphorus and chlorine is decomposed. Analysis
of the products showed that 11.39 g of
phosphorus atoms were produced: Answer using
three significant figures.
What is the percent by mass of phosphorus?
%
What is the percent by mass of chlorine?
%
DONE

Ans: P = 22.5% and Cl = 77.5%

Given:

Total Mass of sample containing P and Cl = 50.51 g

Mass of P produced = 11.39 g

To determine:

Mass % of P and Cl

Explanation:

Mass % of a given element in a total mass is generally expressed as:

Mass % of element = [mass of element/total mass]*100

Here,

Total mass = mass of P + mass of Cl

mass of Cl = Total - mass of P = 50.51-11.39 = 39.12 g

% P = [11.39/50.51]*100 = 22.5%

%Cl = [39.12/50.51]*100 = 77.5%