Week 04 - UA GenChem General Chemistry General Chemistry...

Info iconThis preview shows pages 1–13. Sign up to view the full content.

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: UA GenChem General Chemistry General Chemistry CHEM 151 CHEM 151 Week 4 UA GenChem Week 4 Reading Assignment See D2L CONTENT UA GenChem Counting Particles Counting Particles Is it practical, in a lab situation, to physically Is it practical, in a lab situation, to physically COUNT COUNT the particles? the particles? NO!! The particles are too small! So how do we typically measure the amount of a So how do we typically measure the amount of a substance we have in a laboratory? substance we have in a laboratory? We use the MASS to determine the amount of substance. How is mass related to the number of particles? How is mass related to the number of particles? UA GenChem An explosive and a poison make a material needed for life mass, moles and reacting materials UA GenChem You want to make SALT NaCl From the elements Student A gets Sodium Student B gets Chlorine UA GenChem THE DILEMA HOW MUCH OF EACH MUST YOU GET SO THERE IS NOTHING LEFT OVER AFTER THEY REACT? TOO MUCH SODIUM --- EXPLOSION TOO MUCH CHLORINE -- POISONED UA GenChem What do we know? Because salt is NaCl for every sodium atom there must be one chlorine atom Need to COUNT atoms!!! Number of Na = number of Cl UA GenChem 22.99 g 35.45 g SODIUM CHLORINE CARBON 12.01g UA GenChem Counting Atoms Counting Atoms Chemistry is a Chemistry is a quantitative science quantitative science we need a we need a counting unit. counting unit. 1 mole is the amount of 1 mole is the amount of substance that contains as substance that contains as many particles (atoms, many particles (atoms, molecules) as there are in molecules) as there are in 12.0 g of 12.0 g of 12 12 C. C. MOLE MOLE UA GenChem Particles in a Mole Particles in a Mole 6.02214199 x 10 6.02214199 x 10 23 23 Avogadros Number Avogadros Number There is Avogadros number of particles in a mole of any substance. Amedeo Avogadro Amedeo Avogadro 1776-1856 1776-1856 UA GenChem Relative Mass and Molar Mass 2.0 g of H 2 22.4 L 18.0 g H 2 O 22.4 L 32.0 g O 2 22.4 L 4 Be 9.012 76 Os 190.23 9 F 19.00 Relative Atomic Mass in atomic mass units (amu) Molar Mass if expressed in grams BY EXPERIMENT Each sample contains AVOGADROs Number of particles . 76 UA GenChem Molar Mass Molar Mass The mass of one mole of atoms is called the Molar The mass of one mole of atoms is called the Molar Mass of the element Mass of the element Average Mass Average Mass (g) (g) = = Molar Mass Molar Mass The Molar Mass is the mass of The Molar Mass is the mass of...
View Full Document

Page1 / 43

Week 04 - UA GenChem General Chemistry General Chemistry...

This preview shows document pages 1 - 13. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online