ACTIVITY NAME THAT COMPOUND

Transcription

1 ACTIVITY NAME THAT COMPOUND 1

2 Minute to Name It! A list of chemical formula and names would be shown on the screen. Each student would need to identify the corresponding name (if a formula is given) or formula (if a name is given). 2

3 Li 2 Se AlCl 3 Sr 3 P 2 BaI 2 Mg 2 N 2 KF CaC 2 MgH 2 BeCl 2 Cd 3 P 2 CsCl NaBr BeCl 2 Al 2 O 3 BaS Copper(II) telluride Mercury(II) oxide Stannic fluoride Plumbous bromide Copper(I) chloride Ferric oxide Ferrous oxide Chromium(II) sulfide Chromium(III) oxide Lead(IV) oxide Cobalt(II) fluoride Lead(IV) oxide Nickel(II) phosphide Lead(IV) sulfide Nickel(II) iodide

4 Li 2 Se Lithium selenide Fe 2 O 3 Ferric oxide AlCl 3 Aluminum chloride FeO Ferrous oxide Sr 3 P 2 Strontium phosphide CrS Chromium(II) sulfide BaI 2 Barium iodide Cr 2 O 3 Chromium(III) oxide Mg 3 N 2 Magnesium nitride PbO 2 Lead(IV) oxide KF Potassium fluoride CuTe Copper(II) telluride CaC 2 Calcium carbide HgO Mercury(II) oxide MgH 2 Magnesium hydride SnF 4 Stannic fluoride BeCl 2 Beryllium chloride PbBr 2 Plumbous bromide Cd 3 P 2 Cadmium phosphide CuCl Copper(I) chloride CsCl Cesium chloride CoF 2 Cobalt(II) fluoride NaBr Sodium bromide PbO 2 Lead(IV) oxide BeCl 2 Beryllium chloride Ni 3 P 2 Nickel(II) phosphide Al 2 O 3 Aluminum oxide PbS 2 Lead(IV) sulfide BaS Barium sulfide NiI 2 Nickel(II) iodide

5 Stoichiometry of Formulas and Equations CHAPTER 3

6 Burning Magnesium Chemical reaction: 2 Mg(s) + O 2 (g) 2 MgO(s) 48 amu 32 amu 80 amu How do we look at this in terms of mass?? grams? grams? grams 7

7 Mole (abbreviated mol) SI unit for amount of substance Number of entities as there are atoms in exactly 12 g of 12 C Equal to x entities Called the Avogadro s number 8

8 How big is Avogadro s Number? Volume of world s oceans (L) Age of the earth (s) World population Avogadro s Number: 602,200,000,000,000,000,000,000 Distance from earth to sun (cm) College tuition Spreading 1 mole of marbles over the entire surface of the earth would produce a blanket of marbles almost 5 km high. 9

9 A mole of water 10

10 A mole of other substances O 2 (g) g H 2 O (l) g CaCO g Cu (s) g 11

11 1 mole of Fe vs 1 mole of S 1 mole Fe x Fe atoms g Fe 1 mole S x S atoms g S The mole allows us to count out exactly the same number of things but use mass to do it! 12

12 Molecular Mass and Molar Mass The molecular mass (or molecular weight) is the sum of the atomic masses (in amu) in a single molecule. The molar mass of a covalent compound is numerically equal to the molecular mass, but in grams per mole. 13

13 Formula Mass and Molar Mass The formula mass (or formula weight) is the sum of the atomic masses (in amu) in a formula unit. The molar mass of an ionic compound is numerically equal to the formula mass, but in grams per mole. 14

14 Summary of Different Mass Terms Isotopic Mass 15 Term Definition Unit Atomic Mass (aka Atomic Weight) Molecular or Formula Mass (aka Molecular or Formula Weight) Molar Mass Mass of an isotope of an element Weighted average mass of an element s naturally occurring isotopes Sum of the atomic masses of the atoms (or ions) in a molecule (or formula unit) Mass of 1 mole of a chemical entity (e.g. atoms, ions, molecules, or formula units) amu amu amu grams per mole (g/mol)

15 Practice Problem What is the molecular mass of glucose (C 6 H 12 O 6 )? Molecular Mass: 6 x x x = amu 16

16 Practice Problem Complete the table below for glucose (C 6 H 12 O 6, MW = g/mol) Carbon Hydrogen Oxygen Atoms in 1 glucose molecule Mass C/H/O in 1 glucose molecule Atoms per mole of compound Moles of atoms in 1 mole cmpd Mass per 1 mole of compound x = amu 6 (6.022x10 23 ) atoms 6 moles of atoms 12 x = amu 12 (6.022x10 23 ) atoms 12 moles of atoms 6 x = amu 6 (6.022x10 23 ) atoms 6 moles of atoms g g g 17

17 What s in a Chemical Formula? Al 2 (SO 4 ) 3 (s) 2 atoms of Al and 3 molecules of (SO 4 ) 2-1 formula unit of Al 2 (SO 4 ) 3 = amu 1 mole Al 2 (SO 4 ) 3 = g Al 2 (SO 4 ) 3 1 mole Al 2 (SO 4 ) 3 = x formula units Al 2 (SO 4 ) 3 1 mole Al 2 (SO 4 ) 3 = 2 moles Al 3+ ions 1 mole Al 2 (SO 4 ) 3 = 3 moles (SO 4 ) 2- ions 1 mole Al 2 (SO 4 ) 3 = 12 moles O atoms = 12 x A.N. O atoms 1 mole Al 2 (SO 4 ) 3 = 3 moles S atoms = 3 x A.N. S atoms 1 mole Al 2 (SO 4 ) 3 = 2 moles Al atoms = 2 x A.N. Al atoms 18

18 Conversion Factors in a Molecular Formula H 2 O (l) 1 molecule of H 2 O = 2 H atoms and 1 O atom Molecular mass = (2 x 1.008) = amu Molar mass = g/mol H 2 O 1 mole of H 2 O = x molecules of H 2 O 1 mole of H 2 O = 2 mol H atoms = 2 (6.022x10 23 ) H atoms 1 mole of H 2 O = 1 mol O atoms = 1 (6.022x10 23 ) O atoms 19

19 Conversion Among Different Quantities 20

20 Practice Problem 1. Silver is often used in jewellery and tableware. How many grams of Ag are in mol Ag? 2. Iron, the main component of steel, is the most important metal in industrial society. How many Fe atoms are in 95.8 g of Fe? 3. Urea, (NH 2 ) 2 CO, is a nitrogen-containing compound used as a fertilizer. How many molecules of urea are in a 25.6 g sample? 4. How many hydrogen atoms are present in a 25.6 g sample of urea, (NH 2 ) 2 CO? 21

21 Practice Problem The plant photosynthetic pigment chlorophyll contains 2.68% magnesium by weight. How many atoms of Mg will there be in 1.00 g of chlorophyll? 22