1. Percentage Composition
The idea of percentage composition can be used to help us calculate empirical formulas.
This is the percentage by mass of a particular element in a chemical compound.
Percentage is based on (part ÷ whole) x 100 .
Next >

2. Percentage Composition
To calculate the percentage composition:
% of element in compound =
mass of element in sample of compound × mass of sample of the whole compound (molar mass)
Next >

3. Percentage Composition
Calculate the percentage composition of methane (CH4):
First calculate molar mass for the compound.
Determine how much mass each element contributes to the compound.
mass of element in the compound × molar mass of compound
For hydrogen:
% of element in compound =
mass of hydrogen present in CH × molar mass of CH4
= 4 × × 100 = %
Next >

4. Percentage Composition
For carbon:
% of element in compound =
mass of carbon present in CH4 × molar mass of CH4
= × 100 = %
Check: 25.2% % ≈ 100%
Next >

5. Here is the answer! Pb: 74.51% Cl: 25.49%
PRACTICE QUESTION
Find the percentage compositions of PbCl2 given that the relative atomic masses of Pb and Cl are and respectively.
Here is the answer! Pb: 74.51% Cl: 25.49%
NOW SHOW YOUR WORK TO GET THOSE ANSWERS!
Next >