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Mass Relationships in Chemical Reactions. QUANTITATIVE ANALYSIS. Chapter 3, 10. Micro World atoms & molecules. Macro World grams. Measures individual particles. Measures many particles. 2 Mg + O 2 2 MgO. This is a particle recipe.
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Mass Relationships in Chemical Reactions QUANTITATIVE ANALYSIS Chapter 3, 10
Micro World atoms & molecules Macro World grams Measures individual particles Measures many particles 2 Mg + O2 2 MgO This is a particle recipe So, 2 Mg atoms will react with 1 O2 molecule to make 2 MgO compounds, or 10 Mg atoms will react with 5 O2 molecules to make 10 MgO compounds…. But, will 2 grams of Mg and 1 gram of O2 make 2grams of MgO ?? NO !!! WHY ????
Micro World atoms & molecules Macro World grams Measures individual particles Measures many particles Atomic mass is the mass of an atom in atomic mass units (amu) Use a scale to determine the gram amount By definition: 1 atom 12C “weighs” 12 amu or 1amu = 1/12 (mass 12C)
Micro World atoms & molecules Macro World grams WHAT bridges the two?? Count Amadeo Avogadro in around 1840 discovered a coincidental relationship between the mass of a gas and the number of particles contained in it…. 1776 - 1856
Ar 40 NHe = NNe All Containers have same number of particles NAr 40 grams
Ar 40 40 grams 6.022 x 1023 atoms
H2 2 2 grams 6.022 x 1023 atoms
O2 ? ? grams 6.022 x 1023 atoms
So this special Number (Avogadro’s Number)6.022 x 1023is given the name mole
This type? What the...?
NO! A MOLE IS A QUANTITY NOT A Furry Little Digging Marsupial Or a Skin growth…
IT’S JUST A NUMBER!!!!!!!!!!!!!!! 6.022 x 1023
Dozen = 12 Pair = 2 The mole (mol) is the amount of a substance that contains as many elementary entities as there are atoms in exactly 12.00 grams of 12C 1 mol = nA = 6.022 x 1023 Avogadro’s number (nA)
A MOLE is simply……… 6.022 x 1023
6 times what??
OR…. 602200000000000000000000
One Mole ofThings 6.022 x 1023 Things
One Mole ofcars 6.022 x 1023 cars
One Mole ofrice 6.022 x 1023 rice grains
OR…………………..One Mole of: S C Hg Cu Fe 3.2
So, if you have ONE MOLE of anysubstance, then that substance willhave a weight equal to its atomic mass!1 mol Ca atoms = 40.1 grams 1 mole He = 4.0 grams
1 mole of pennies would give each person on Earth over 1 trillion dollars!!!!
Stacked up it would be 1.62 million Light years tall !!!!!!!!!!!!!!!!!!!!!!!!
1.62 million Light years is way out Of our Milky Way Galaxy & about 2/3 the way to the Andromeda Galaxy !!!!!!!!!
OR…………………..One Mole of: S C Hg Cu Fe 3.2
How Big a Bowl would you need in order to hold a MOLE of RICE?
Mole of Rice !!!!!!!! THE ENTIRE SURFACE OF EARTH… COVERED 30 METERS DEEP….!!!
But yet…..One Mole of: S C 32.1g 12 g 200.1g Hg 55.8g 63.5g Cu Fe 3.2
Another Definition of a.mu. 1 amu = 1 g/mole So, for carbon… 12 amu = 12 g/mol Or … 12g of carbon = 1 mol of carbon ! Or 24g of carbon = 2 mol of carbon ! So what? So…if we know the amount of grams of substance we have, then we know how many moles of substance we have, WHICH MEAN WE KNOW HOW MANY PARTICLES (ATOMS, ETC.) WE HAVE!!
One Mole of WATER (H2O) 18.0 g
One Mole of SODIUM HYDROXIDE (NaOH) 40.0g
? Mole of SODIUM HYDROXIDE (NaOH) 350g
0.l75 Mole of SODIUM HYDROXIDE (NaOH) ?? g
Particle-city Mass-ville Molecules/atoms grams Periodic Table Avogadro's # Mole Island PV=nRT n = M·V 1 mol = 22.4 L Solution-city Volume (L) Gas-isle (any TP) volume (L) Gas-isle @ STP volume (L)