RelativeResourceManager-3

RelativeResourceManager-3 - Sxn E: The Mole Atoms are so...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Sxn E: The Mole Atoms are so small that a convenient way of counting numbers of atoms is necessary Best: count by weight! E1 Mole (mol): number of objects (atoms, molecules, etc.) equal to the number of atoms present in exactly 12 grams of carbon-12 Mole (mol): number of objects (atoms, molecules, etc.) equal to the number of atoms present in exactly 12 grams of carbon-12 Mass of C-12 atom = 1.9926 × 10 -23 g 1 mol of C-12 atoms = 12 g of C-12 atoms = 6.0221 × 10 23 C-12 atoms This is known as Avogadro’s Number N A = 6.022 x 10 23 items/mol A mole of various elements E2 32 g S 210 g Hg 207 g Pb 64 g Cu 12 g C Each contains 6.022 x 10 23 atoms!
Background image of page 1

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

View Full DocumentRight Arrow Icon
2 Amount of substance in mol: n Number of substance ‘pieces’ N = nN A And n = N / N A So 1.27 x 10 19 atoms of Na = 2.11 x 10 -5 mol of Na But can we relate mass to moles? YES! If we know the weight of one unit of what we are interested in we can multiplying that by N A will give us the weight of one mole of it! This is the MOLAR MASS
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/08/2008 for the course CHEM 6A taught by Professor Pomeroy during the Winter '08 term at UCSD.

Page1 / 5

RelativeResourceManager-3 - Sxn E: The Mole Atoms are so...

This preview shows document pages 1 - 3. Sign up to view the full document.

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