Unit 3 Chemical Equations and Stoiciometry - Notebook: Percentage Composition Percentage Composition
Unit 3 Chemical Equations and Stoiciometry - Notebook: Percentage Composition Percentage Composition
Unit 3 Chemical Equations and Stoiciometry - Notebook: Percentage Composition Percentage Composition
3 Chemical Equations and stoiciometry.notebook
percentage composition
Percentage Composition
mass of element present in 1 mol of compound
Mass % = x 100
mass of 1 mol of compound
What percentage of the day do you spend sleeping?
Find the mass percentage of all elements in the compound.
Part 7 hours
x 100 = 29% Note that because of rounding the sum of the % may not add up
Total 24 hours to 100%.
Ethanol C2H5OH
A compound was analyzed and found to contain 13.5 g
Determining Empirical Formula Ca, 10.8 g O, and 0.675 g H. What is the empirical formal
for the compound?
A formula that gives you the simplest whole number ratio of the
atoms of the elements is called the empirical formula.
You are given a compound that is 80.0% C by mass and 20.0%
H by mass. What is its Empirical Formula?
(Assume you have 100g of the compound so 80.0% is 80.0g!)
The smallest whole number ratio of these amounts can be
found by dividing each mole value by the smallest of the two
values.
Determining Molecular Formula
Ribose is an important sugar that is found in DNA and RNA. Ribose has
The formula that gives the actual number of atoms of each element a molar mass of 150 g/mol and a chemical composition of 40.0% C,
in a molecular compound is called the molecular formula. 6.67% H, and 53.3 % O. What is the molecular formula for Ribose?
The Molecular Formula is always whole number multiple of the
empirical formula.
Molecular formulas cannot be used to describe ionic substances. As
the name implies, molecular formulas are for molecular substances.