Download presentation
Presentation is loading. Please wait.
Published byBlaise Davidson Modified over 9 years ago
2
Shows the percent by mass of each element in a compound.
3
Calculate the molar mass of the compound Divide the total mass of each element by the molar mass of the compound and multiply by 100.
4
What is the percent composition of Aluminum hydroxide? Al(OH) 3 1 Al @ 27.0 = 27.0 3 O @ 16.0 = 48.0 3 H @ 1.0 = 3.0 78.0 g/mol 27.0/78.0*100 = 34.6 % Al 48.0/78.0*100 = 61.5 % O 3.0/78.0*100 = 3.8 % H
5
Calculate the percent composition of each of the following: Tin IV sulfate 38.2 % Sn20.6 % S41.2 % O Carbon tetrachloride 7.8 % C92.2 % Cl Nitric acid 1.6 % H22.2 % N76.2 % O
6
The lowest whole number ratio of elements in a compound.
7
Treat the compound as if it were 100 grams. Convert each element to moles (don’t use diatomics because they are not alone). Divide by the least number of moles. If there is a decimal multiply all by the lowest whole number to get whole number. These numbers are your subscripts in your empirical formula.
8
What is the empirical formula of a compound that is 75% C and 25% H?
9
What is the empirical formula of a substance that is 81.8% C and 18.2% H? What is the empirical formula of a substance that is 82.76% C and 17.24% H? What is the empirical formula of a substance that is 84.21% C and 15.79% H? What is the empirical formula of a substance that is 66.67% C, 15.56% H, and 17.78% O?
10
Whole number multiple of the empirical formula showing the actual amount of atoms in a compound.
11
Determine the empirical formula. Calculate the molar mass of the empirical formula. Divide the molar mass of the molecular formula (given) by the molar mass of the empirical formula. Use this number as a multiplier for your empirical formula.
12
Example A molecule is 75 % Carbon and 25 % Hydrogen with a molecular mass of 48 g/mol. What is the molecular formula?
13
What is the molecular formula of a compound that is 54.54% Carbon, 9.09% Hydrogen, and 36.36% oxygen. The molar mass of the compound is 88 g/mol.
14
What is the molecular formula of a compound that is 58.06% carbon, 19.35% hydrogen, and 22.58% nitrogen? The molar mass of the compound is 248 g/mole.
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.