 # Chemical Reactions and Quantities The Mole Calculations Using Molar Mass.

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Chemical Reactions and Quantities The Mole Calculations 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 10 23 particles 1 mole C = 6.02 x 10 23 C atoms 1 mole H 2 O = 6.02 x 10 23 H 2 O molecules 1 mole NaCl = 6.02 x 10 23 Na + ions and 6.02 x 10 23 Cl – ions

More Examples of Moles Moles of elements 1 mole Mg = 6.02 x 10 23 Mg atoms 1 mole Au = 6.02 x 10 23 Au atoms Moles of compounds 1 mole NH 3 = 6.02 x 10 23 NH 3 molecules 1 mole C 9 H 8 O 4 = 6.02 x 10 23 aspirin molecules

Avogadro's Number 6.02 x 10 23 particles 1 mole or 1 mole 6.02 x 10 23 particles

22.4L 1 mole L 22.4 L 1 mole a.m.u. 6.02 x 10 23 1 mole 6.02 x 10 23

Using Avogadro’s Number 1. Number of atoms in 0.500 mole of Al 1) 500 Al atoms 2) 6.02 x 10 23 Al atoms 3) 3.01 x 10 23 Al atoms 2.Number of moles of S in 1.8 x 10 24 S atoms 1) 1.0 mole S atoms 2) 3.0 mole S atoms 3) 1.1 x 10 48 mole S atoms

Solution 1. Number of atoms in 0.500 mol of Al 3) 3.01 x 10 23 Al atoms 2. Number of moles of S if a sample of S contains 4.50 x 10 24 S atoms 2) 3.0 mole S atoms

Molar Mass n n Number of grams in 1 mole n n 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 CaCl 2 = 111.1 g/mole 1 mole Ca x 40.1 g/mole + 2 moles Cl x 35.5 g/mole 1 mole of N 2 O 4 = 92.0 g/mole 2 moles N x 14.0 g/mole + 4 moles O x 16.0 g/mole

Molar Mass A. 1 mole of K 2 O = ______g B. 1 mole of antacid Al(OH) 3 = ______g

Solution A. 1 mole of K 2 O= 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 C 5 H 8 NO 4 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 CH 4 Methane CH 4 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 CH 4 = 16.0 g 16.0 g CH 4 and 1 mole CH 4 1 mole CH 4 16.0 g CH 4

Molar Mass Acetic acid CH 3 COOH 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 CH 3 COOH 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

Calculations with Molar Mass molar mass Grams Moles

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 C 14 H 18 N 2 O 5 is used to sweeten diet foods, coffee and soft drinks. How many moles of aspartame are present in 225 g of aspartame?

Solution 1. Molar mass of Aspartame C 14 H 18 N 2 O 5 (14 x 12.0) + (18 x 1.01) + (2 x 14.0) + (5 x 16.0) = 294 g/mole 2. Setup 225 g aspartame x 1 mole aspartame 294 g aspartame = 0.765 mole aspartame

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