- The Mole Concept helps us measure the amount of a substance that is in an compound element
- Formula mass in Grams of a substance that contains one mole of particles
- Avogadro's Number = 6.02 x 10^23
- Example:
0.750 moles X 6.02 x 10^23 moles X 5 Carbons = 2.26 x 10^24 Carbon
1 1 mole 1 molecule
- Ways to Remember: Always Fractions!! Moles = Fraction
- Matter is split in 2 categories: Pure Substance and Mixture
- Pure Substance: A substance that CAN NOT be physically broken down
- Element- Only made up of one type of atom, CAN NOT be broken down into simpler substances
- Compound- Made up of 2 or more atoms (made up of 2 or more elements), CAN BE chemically separated into elements
- Mixture: Combination of 2 or more substances that CAN BE physically separated back into there individual parts with out changing
- Homogeneous- Evenly spread, the individual substances making up the substance CAN NOT be seen.
- Heterogeneous- Not evenly spread, the individual substances making up the substance CAN BE seen
- Diatomic Element: The seven gas elements that form molecules because they don't have full valance shells on their own: Bromine (Br), Iodine (I), Nitrogen (N), Chlorine (Cl), Hydrogen (H), Oxygen (O), and Fluorine (F).
- Ways to remember them are: BrINClHOF as Have No Fear Of Ice Cold Beer.
- Pure Substance: A substance that CAN NOT be physically broken down
- Molecular Formula: The Total number of atoms of each element in a compound. Example: CH4
- Empirical Formula: The Total number of elements in a compound. Example: CH2O
- Examples:
- Molecular Formula to Empirical Formula: Find Greatest Common Factor then Divide C2H4 = CH2
- Empirical Formula to Molecular Formula: - Find Atomic Mass, Multiple mass by quantity of each element, then add both masses together CH2 = C: 12.01 x 1= 12.01 12.01 dddddd H: 1.01 x 2 = 2.02 + 2.02 So, CH2 = 14.03 grams
- Ways to Remember:
- Empirical to Molecular, for this you need an equation so Equation and Empirical both start with the letter E
- Molecular to Empirical, for this you do simple math (only division) so when you start with Molecular you do a simple Magh problem
- Identifies the elements present in a compound as a mass percent of the total compound mass
- Formula: % composition by mass = mass of element/mass of whole mass x 100%
- Example: H2O2 = H: 1.01 x 2 = 2.02 & O: 16.00 x 2 = 32.00, So 2.02 + 32.00 = 34.02 H% = 2.02/34.02 x 100% = 5.9% O% = 32.00/34.02 x 100% = 94%
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