# Chap3 - Divide weight in grams by atomic weight Finding...

This preview shows pages 1–2. Sign up to view the full content.

Sheet1 Page 1 Chapter 3: Stoichiometry -Numbers and quantities associated with chemical formulas and equations Atomic Mass: Standard system in 1961: (superscript 12)C is assigned a mass of exactly 12 atomic mass units (amu) -THe masses of all other atoms rleated to the standard (superscript 12)C Mass Spectrometer: Instrument used to measure the masses of atoms Atomic mass = Atomic weight Definition of Average Atomic Mass: A) The weighted average of the atomic masses of all the isotopes of the element B) E(Sigma)[(isotope mass) x (fractional isotope abundance)] for all isotopes of the element. Calculation of average atomic mass: A) Naturally occuring Bromine consists of 50.69% amu and 49.31% (superscript 81)Br of atomic mass 80.92 amu. Calculate t h Mole: -THe amount of substance that contains as many particles as the number of atoms in exactly 12g of (superscript 12)C. Avogadro's number: 6.022 x 10^23 Finding mol of an element:

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Divide weight in grams by atomic weight Finding atoms: How many atoms of Potassium are present in 6.3mol of K 6.3 x atomic weight of K Molar mass: The sum of the atomic masses of each element in one mole of a compound expressed in grams. Units: g/mol Calculating Molar Mass: NH4NO3 (ammonium nitrate) (take atomic weight from each element and add them to obtain compound's weight) N: 14.008 H(4): 1.0080 N: 14.008 O(3): 16.00-Add these Chemical Equations: Shorthand representation of a chemical reaction. Atoms undergo reorganization. Bonds are broken and reformed Empirical Formula: Simplest formula of a compound which will show the relative whole number of each element in 1mol of a compound Molecular Formula: A formula that shows the actual number of each element present in 1mol of the compound ElementCarbonHydrogenOxygen Sheet1 Page 2 Percent48.648.1643.20 Atomic Weight12.011.00816.00...
View Full Document

{[ snackBarMessage ]}

### Page1 / 2

Chap3 - Divide weight in grams by atomic weight Finding...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online