Percentage Composition Flashcards
1
Q
Formula for Mass Percent
A
Mass of element in compound divided by mass of the compound, x 100
2
Q
Law of Definite Proportions
A
*t! A compound always contains the same proportion of elements by mass
evenif mass changes, percentages stay the same
3
Q
Law of Definite Proportions: Quantity of compound is unknown
A
- Use molar mass to find the mass of each element and the compound per 1 mole
Then divide using formula - All percents should add to 100
- Units do not matter as they will cancel out in formula
4
Q
Percentage Composition connected to Technology, Society and the Real World
A
- Helps to identify chemicals (through empirical and molecular formula)
- Helps to synthesize chemicals in the lab due to fixed ratios
- Medicinal drugs, vitamins, household detergent
- Helps to extract elements from a compound
- As most metals are not found as pure elements
- How much percentage to take out to get metal in compound
