Chemical Reactions and Quantities The Mole Calculations Using Molar Mass.
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Transcript of Chemical Reactions and Quantities The Mole Calculations Using Molar Mass.
Chemical Reactions and Chemical Reactions and QuantitiesQuantities
The MoleThe Mole
Calculations Using Molar MassCalculations Using Molar Mass
Collection Terms
1 trio = 3 singers
1 six-pack Cola = 6 cans Cola drink
1 dozen donuts = 12 donuts
1 gross of pencils = 144 pencils
A Mole of Particles
Contains 6.02 x 1023 particles
1 mole C = 6.02 x 1023 C atoms
1 mole H2O = 6.02 x 1023 H2O molecules
1 mole NaCl = 6.02 x 1023 Na+ ions and
6.02 x 1023 Cl– ions
More Examples of Moles
Moles of elements
1 mole Mg = 6.02 x 1023 Mg atoms
1 mole Au = 6.02 x 1023 Au atoms
Moles of compounds
1 mole NH3 = 6.02 x 1023 NH3 molecules
1 mole C9H8O4 = 6.02 x 1023 aspirin molecules
Using Avogadro’s Number
1. Number of atoms in 0.500 mole of Al1) 500 Al atoms
2) 6.02 x 1023 Al atoms3) 3.01 x 1023 Al atoms
2.Number of moles of S in 1.8 x 1024 S atoms1) 1.0 mole S atoms2) 3.0 mole S atoms3) 1.1 x 1048 mole S atoms
Solution
1. Number of atoms in 0.500 mol of Al3) 3.01 x 1023 Al atoms
2. Number of moles of S if a sample of S contains 4.50 x 1024 S atoms2) 3.0 mole S atoms
Molar Mass
Number of grams in 1 mole
Equal to the numerical value of the atomic
mass
1 mole of C atoms = 12.0 g
1 mole of Mg atoms = 24.3 g
1 mole of Cu atoms = 63.5 g
Molar Mass
Give the molar mass to 0.1 g
A. 1 mole of Br atoms = ________
B. 1 mole of Sn atoms = ________
Solution
Give the molar mass to 0.1 g
A. 1 mole of Br atoms = 79.9 g/mole
B. 1 mole of Sn atoms = 118.7 g/mole
Molar Mass of Compounds
Mass in grams of 1 mole equal numerically to the sum of the atomic masses
1 mole of CaCl2 = 111.1 g/mole
1 mole Ca x 40.1 g/mole
+ 2 moles Cl x 35.5 g/mole
1 mole of N2O4 = 92.0 g/mole
2 moles N x 14.0 g/mole + 4 moles O x 16.0 g/mole
Solution
A. 1 mole of K2O = 94.2 g
2 K x 39.1 g/mole + 1 O x 16.0 g/mole
B. 1 mole of antacid Al(OH)3 = 78.0 g
1 Al x 27.0 g/mole + 3 O x 16.0 g/mole
+ 3 x 1.0
Percent Composition
What is the percent carbon in C5H8NO4 in
this compound that is used to flavor
foods and tenderize meats?
1) 8.22 %C
2) 24.3 %C
3) 41.1 %C
Solution
Molar mass = 146.0 g/mole
% = total g C x 100
total g compound
= 60.0 g C x 100 = 41.1% C
146.0 g MSG
Molar Mass Factors for CH4
Methane CH4 known as natural gas is used in gas cook tops and gas heaters. Express the molar mass of methane in the form of conversion factors.
Molar mass of CH4 = 16.0 g
16.0 g CH4 and 1 mole CH4
1 mole CH4 16.0 g CH4
Molar Mass
Acetic acid CH3COOH is the acid in vinegar . It
has a molar mass of 60.0 g/mole.
1 mole of acetic acid = ____________
1 mole acetic acid or g acetic acid g acetic acid 1 mole acetic acid
Solution
Acetic acid CH3COOH is the acid in vinegar . It
has a molar mass of 60.0 g/mole.
1 mole of acetic acid = 60.0 g
1 mole acetic acid or 60.0 g acetic acid 60.0 g acetic acid 1 mole acetic acid
Moles and Grams
Aluminum is often used for the structure of light-weight bicycle frames. How many grams of Al are in 3.00 moles of Al?
3.00 moles Al ? g Al
1. Molar mass of Al
1 mole Al = 27.0 g Al
2. Conversion factors for Al
27.0g Al or 1 mol Al
1 mol Al 27.0 g Al
3. Setup
3.00 moles Al x 27.0 g Al
1 mole Al
Answer = 81.0 g Al
Molar Mass
The artificial sweetener aspartame
(Nutri-Sweet) formula C14H18N2O5 is
used to sweeten diet foods, coffee and
soft drinks. How many moles of
aspartame are present in 225 g of
aspartame?