# Programme in mole calculation

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 Programme in mole calculation Step 1 Start at the very beginning Atoms are very small indeed! If we draw a line 1 metre long, 6,000,000,000 (6 billion) atoms could be lined end to end. So a scientist cannot count atoms, ions or molecules directly. They are far too small and numerous. Instead a scientist counts particles by weighing. This is rather like in a bank. A bank cashier has not got the time to count every coin. She weighs the bags of coins on special scales which tell her how much they are worth. Hydrogen is the lightest atom, we say that hydrogen has a relative atomic mass of 1. In 1g of hydrogen atoms we say that we have 1 mole of hydrogen atoms. Experiments have shown that an atom of carbon weighs 12 times as much as an atom of hydrogen, so the relative atomic mass of carbon is 12. In 12g of carbon atoms we say that we have 1 mole of carbon atoms. Let's look at the following table which shows the relation between the mass of one mole element and the relative atomic mass. Element relative atomic mass mass of one mole element hydrogen 1 1g carbon 12 12g All answers throughout the programme should be collected to 3 sig. figures Class work 1: Use your Periodic Table to find out the mass of one mole of the following atoms. a. Helium b. Iron c. Potassium d. Sulphur e. Platinum f. Tin g. Silver h. Phosphorus. d. e. f. g. h. Actually one mole of atoms has 6.00x10 23 atoms. The scientific "magic number" is called Avogadro's number or Avogadro's constant (L).

2 P.2 Example 1: How many atoms are there in 6g of carbon? The relative atomic mass of carbon is 12. In 12g of carbon there are 6.00x10 23 atoms which equal one mole of carbon atoms. In 6g of carbon there is only half mole, 6 no. of moles of carbon = = Class work 2a: Use your periodic table to help you. How many atoms are there in a. 1.0g of helium b. 28.0g iron c. 13.0g potassium d. 6.4g sulphur e. 32.5g platinum f. 119g tin g. 27.0g silver h. 10.3g phosphorus? d. e. f. g. h. Class work 2b: How many moles of the following atoms? a. 3.0x10 23 hydrogen atoms a. b. 1.5x10 23 oxygen atoms b. c. 1.5x10 23 nitrogen atoms c. d. 3.0x10 23 carbon atoms. d. Put your answers in table form: Hydrogen oxygen nitrogen carbon number of atoms 3.0x x x x10 23 number of mole What do you discover?

3 P.3 Step 2 Masses into moles - moles into masses The following calculation will make use of the equation: actual mass of no. of moles of atoms = molar mass of the atoms the atoms Example 2: How many moles of atoms are there in 4g of calcium? [A r (Ca) = 40] By rearranging equation above, it is just as easy to find out the mass of a fraction of a mole. 4 no. of moles of calcium = = Example 3: What is the mass of 1/8 mole of copper? [A r (Cu) = 64] First equation above must be rearranged: mass = no. of moles x molar mass = 1/8 x 64 = 8 (g) (don't forget the unit) Classwork 3: 1. How many moles of atoms are there in a. 20g calcium b. 54g aluminium c. 11.2g iron d. 78g potassium e. 8g sulphur f. 2.4g magnesium? d. e. f. 2. What is the mass of a. 1/10 mole of sodium atoms b. 2 moles of silver atoms c. 1/3 mole of carbon atoms d. 8 moles of iron atoms e. 1/16 mole of magnesium atoms f. 1/4 mole of copper atoms? d. e. f.

4 P.4 Classwork 4: Here are the creep point questions. Avogadro's number = 6.00x How many atoms are there in a. 1 mole of carbon atoms b. 2 moles of oxygen atoms c. 1/2 mole of sulphur atoms d. 1/3 mole of lead atoms? e. What mass of magnesium contains 2.00x10 23 atoms? f. What mass of carbon contains 2.00x10 23 atoms? g. What mass of magnesium has five times as many atoms as 2g of carbon? h. What mass of potassium has the same number of atoms as 8g of magnesium? d. e. f. g. h. Step 3 Diatomic molecules Sometimes an element exists as molecules. Molecules are groups of atoms held together by chemical bonds. A hydrogen atom has a relative atomic mass of 1. A hydrogen gas molecule (H 2 ) has two hydrogen atoms, then the relative molecular mass (M r ) of the molecule is 2. To have one mole of molecules we should need to weigh out 2g of hydrogen gas. Let's look at the following table which shows the relation between the mass of one mole molecules and the relative molecular mass. molecule relative molecular mass mass of one mole molecules hydrogen (H 2 ) 2 2g nitrogen (N 2 ) 28 28g Referring to the equation on page 3, now we come to have a similar equation: actual mass of no. of moles of molecules = molar mass of the molecules the molecules

5 P.5 Example 4: How many moles of nitrogen molecules are present in 7g of nitrogen gas? First note that the question did not ask about nitrogen atoms. It concerns nitrogen molecules, N 2. Each molecule contains two atoms of nitrogen. Since each atom has a relative atomic mass of 14, then the relative molecular mass of nitrogen molecule is 2 x 14 = 28. Example 5: What is the mass of 10 1 mole of oxygen gas? [Ar (O) = 16] Oxygen is a diatomic gas also. It has the relative molecular mass of 2 x 16 = 32. Now rearrange the basic equation on page 4: mass = number of mole x relative molecular mass = 10 1 x 32 = 3.2 (g) Classwork 5: 1. How many moles of a. chlorine molecules are present in 7.1g of chlorine gas, b. chlorine atoms are present in 7.1g of chlorine gas, c. oxygen molecules are present in 64g of oxygen gas? d. oxygen atoms are present in 64g of oxygen gas? d. 2. What is the mass of a. 1/8 mole of oxygen gas b. 1/4 mole of bromine gas c. 2 moles of chlorine gas d mole of iodine? d.

6 P.6 Step 4 Compounds Some compounds are also made up of molecules. But a compound contains atoms of different elements joined together by chemical bonds. The formula for water is H 2 O. This means that a molecule of water contains two atoms of hydrogen and one atom of oxygen. To work out the mass of one mole of a compound we use the same idea as in Step 3. The relative atomic masses of all the atoms in the compound are added together. Let's look at the following table which shows the relation between the mass of one mole compound and the relative formula (molecular) mass. molecule relative (formula) molecular mass mass of one mole compound water (H 2 O) 1x2+16 = 18 18g ammonia (NH 3 ) 14+1x3 = 17 17g Example 6: What is the mass of one mole of carbon dioxide? [A r (C) = 12, A r (O) = 16] The carbon dioxide molecule contains 1 carbon atom and 2 oxygen atoms. The relative molecular mass is equal to x2 = 44. The mass of one mole of carbon dioxide is 44g. Example 7: What is the relative formula mass of magnesium nitrate Mg(NO 3 ) 2? [A r (Mg) = 24 A r (N) = 14, A r (O) = 16] Each mole of magnesium nitrate contains 1 mole magnesium ions, 2 moles of nitrogen and 6 moles of oxygen. So the relative formula mass is x14 + 6x16 = 148. Classwork 6: Find the relative formula mass of a. copper(ii) oxide b. sulphur trioxide c. copper(ii) sulphide d. copper(ii) carbonate e. zinc nitrate f. ammonium carbonate. d. e. f.

7 P.7 Referring to the equation on pages 3 and 5, now we have another similar equation: Example 8: actual mass of the substance no. of moles of any substance = molar mass of the formula How many moles are contained in 72g of water? The relative molecular mass of water is 18, so 72 no. of moles of water = = 4 18 Example 9: How many moles of hydrogen atoms and oxygen atoms are contained in 72g of water? Since each mole of water contains 2 moles of hydrogen atoms and 1 mole of oxygen atoms, 4 moles of water contain 8 moles of hydrogen atoms and 4 moles of oxygen atoms. Classwork 7: Find the number of moles contained in a. 40g copper(ii) sulphate b. 282g of zinc nitrate c. 60g sulphur trioxide d. 32g ammonium carbonate. d. Classwork 8: Find the mass of a. 0.5 mole copper(ii) carbonate a. b. 1/4 mole copper(ii) oxide b. c. 1/10 mole of sulphur trioxide c. d mole ammonium carbonate. d.

8 P.8 Revision exercise 1 Take Avogadro's constant = 6.0x g hydrogen gas contain mole(s) of hydrogen molecules, mole(s) of hydrogen atoms, hydrogen molecules and hydrogen atoms x10 23 particles of CO 2 is equivalent to mole(s) of CO 2, g of CO Find the relative molecular mass of a. sulphuric acid, H 2 SO 4 b. ammonium sulphate, (NH 4 ) 2 SO 4 c. hydrated copper(ii) sulphate, CuSO 4 5H 2 O. 4. What is the mass of a. 2 moles of magnesium atoms b. 1/2 mole of copper atoms c mole of calcium atoms? 5. How many atoms are there in a. 1 mole of carbon atoms b. 0.5 mole of oxygen atoms c. 1/3 mole of sulphur atoms? 6. How many atoms are there in a. 39.0g of potassium b. 6.35g of copper c. 60.0g of calcium? 7. What is the mass of a. 4 moles of water b. 0.5 mole of sodium thiosulphate, Na 2 S 2 O 3 c mole of ammonium dichromate, (NH 4 ) 2 Cr 2 O 7?

9 20g sugar 10g sugar P.9 Step 5 Molarity a unit of concentration of solution Concentration is a measure of how much solute dissolved in a unit volume of the solution. For example, if you dissolve 10g sugar in water so that the volume of solution is 10cm 3, then the concentration of the sugar solution is 10g in 10cm 3 or 1g/cm 3. Then the unit of concentration is g/cm 3, kg/cm 3, kg/m 3 etc. It is very convenient to use figure to compare the concentrations of different solutions. For example, two solutions Molarity is one kind of units of concentration the unit is mol/dm 3. no.of moles of solute molarity = volume of solution in dm3 molarity = (M) = 10.0M no. of moles of NaCl = mass of NaCl formula mass of NaCl 58.5 = 1 no. of moles of NaCl = 58.5 Class work 9 : 1. Calculate the concentration of the following solutions. a g sodium chloride in 250cm 3 solution no. of moles of sodium chloride =

10 1. In order to prepare the following solutions, how many grams of the solution is required? P.10 b g copper(ii) sulphate in 0.5dm 3 solution. c. 44.8g sulphur dioxide in 700cm 3 solution. Class work cm 3, 0.5M copper(ii) chloride solution no. of moles of copper(ii) chloride required = mass of copper(ii) chloride required = 250cm 3, 0.45M sodium hydroxide solution 2dm3, 1.5M potassium nitrate solution 2. What is the volume of the solutions in order to make a. 0.1M solution by dissolving 13.45g copper(ii) chloride? no. of moles of copper(ii) chloride dissolved = volume of the solution (dm 3 ) = b M solution by dissolving 1.825g hydrogen chloride? no. of moles of hydrogen chloride dissolved = volume of the solution (dm 3 ) =

11 P.11 Answer of the class work Class work 1 a. 4.00g b. 56.0g c. 39.0g d. 32.0g e. 195g f. 119g g. 108g h. 31.0g Class work 2a a. 1.5x10 23 b. 3.0x10 23 c. 2.0x10 23 d. 1.2x10 23 e. 1.0x10 23 f. 6.0x10 23 g. 1.5x10 23 h. 2.0x10 23 Class work 2b a. 0.5 b c d. 0.5 Hydrogen oxygen nitrogen carbon number of atoms 3.0x x x x10 23 number of mole Class work 3 1. a b c d e f a. 2.30g b. 216g c. 4.00g d. 448g e. 1.50g f. 15.3g Class work 4 a. 6x10 23 b. 12x10 23 c. 3x10 23 d. 2x10 23 e. 8.00g f. 4.00g g. 20.0g h. 13.0g Class work 5 1. a b c d a. 4.00g b. 40.0g c. 142g d. 63.5g Class work 6 a b c d. 124 e. 189 f Class work 7 a b c d

12 P.12 Class work 8 a. 61.8g b. 19.9g c. 8.00g d. 24.0g Revision exercise , 1.50, 4x10 23, 9x , a b. 132 c a. 48.0g b. 31.8g c. 30.0g 5. a. 6x10 23 b. 3x10 23 c. 2x a. 6x10 23 b. 6x10 22 c. 9x a. 72.0g b. 79.0g c. 63.0g class work 9 1. a. 0.25, 1.0M b. 0.6M c. 1.0M class work a. 0.1, 13.45g b. 4.5g c g 2. a. 0.1, 1.0dm 3 b. 0.05, 2.0dm 3

### 21 st Century Chemistry Multiple Choice Question in Topic 3 Metals Unit 11

21 st Century Chemistry Multiple Choice Question in Topic 3 Metals Unit 11 1. Consider the equation: 2Ca(s) + O 2 (g) 2CaO(s) Which of the following statements are correct? (1) Calcium and oxygen are reactants.

### Unit 3 Notepack Chapter 7 Chemical Quantities Qualifier for Test

Unit 3 Notepack Chapter 7 Chemical Quantities Qualifier for Test NAME Section 7.1 The Mole: A Measurement of Matter A. What is a mole? 1. Chemistry is a quantitative science. What does this term mean?

### Chemistry Post-Enrolment Worksheet

Name: Chemistry Post-Enrolment Worksheet The purpose of this worksheet is to get you to recap some of the fundamental concepts that you studied at GCSE and introduce some of the concepts that will be part

### WRITING CHEMICAL FORMULA

WRITING CHEMICAL FORMULA For ionic compounds, the chemical formula must be worked out. You will no longer have the list of ions in the exam (like at GCSE). Instead you must learn some and work out others.

### B. Elements: We cannot determine how many electrons are lost for the elements b/c their in their valence electrons can change.

Unit 6 Notepack: Chapters 9 &10 Chemical Quantities 9.1 Naming Ions NAME Period: A. ions: Ions made of single. B. Elements: There is a pattern in predicting how many electrons are lost and gained for the

### CHEMICAL QUANTITIES. Chapter 10

CHEMICAL QUANTITIES Chapter 10 What is a mole? A unit of measurement in chemistry 1 mole of a substance = 6.02 x 10 23 (Avagadro s number) representative particles of a substance Representative particle

### MOLES AND MOLE CALCULATIONS

35 MOLES ND MOLE CLCULTIONS INTRODUCTION The purpose of this section is to present some methods for calculating both how much of each reactant is used in a chemical reaction, and how much of each product

### Quantitative aspects of chemical change: Moles and molar mass

OpenStax-CNX module: m38717 1 Quantitative aspects of chemical change: Moles and molar mass Free High School Science Texts Project This work is produced by OpenStax-CNX and licensed under the Creative

### TOPIC 7. CHEMICAL CALCULATIONS I - atomic and formula weights.

TOPIC 7. CHEMICAL CALCULATIONS I - atomic and formula weights. Atomic structure revisited. In Topic 2, atoms were described as ranging from the simplest atom, H, containing a single proton and usually

### Chemical Quantities: The Mole Chapter 7 Assignment & Problem Set

Chemical Quantities: The Mole Name Warm-Ups (Show your work for credit) Date 1. Date 2. Date 3. Date 4. Date 5. Date 6. Date 7. Date 8. Chemical Quantities: The Mole 2 Study Guide: Things You Must Know

### Study Guide For Chapter 7

Name: Class: Date: ID: A Study Guide For Chapter 7 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. The number of atoms in a mole of any pure substance

### Topic 4 National Chemistry Summary Notes. Formulae, Equations, Balancing Equations and The Mole

Topic 4 National Chemistry Summary Notes Formulae, Equations, Balancing Equations and The Mole LI 1 The chemical formula of a covalent molecular compound tells us the number of atoms of each element present

### Formulae, stoichiometry and the mole concept

3 Formulae, stoichiometry and the mole concept Content 3.1 Symbols, Formulae and Chemical equations 3.2 Concept of Relative Mass 3.3 Mole Concept and Stoichiometry Learning Outcomes Candidates should be

### ATOMS. Multiple Choice Questions

Chapter 3 ATOMS AND MOLECULES Multiple Choice Questions 1. Which of the following correctly represents 360 g of water? (i) 2 moles of H 2 0 (ii) 20 moles of water (iii) 6.022 10 23 molecules of water (iv)

### Atomic mass and the mole

Atomic mass and the mole An equation for a chemical reaction can provide us with a lot of useful information. It tells us what the reactants and the products are in the reaction, and it also tells us the

### MOLE CONVERSION PROBLEMS. 2. How many moles are present in 34 grams of Cu(OH) 2? [0.35 moles]

MOLE CONVERSION PROBLEMS 1. What is the molar mass of MgO? [40.31 g/mol] 2. How many moles are present in 34 grams of Cu(OH) 2? [0.35 moles] 3. How many moles are present in 2.5 x 10 23 molecules of CH

### Notes: Formula Mass and Percent Composition

Notes: Formula Mass and Percent Composition Formula mass - the mass of one mole of a compound, atom or ion. -also called: gram formula mass, molecular mass, gram molecular mass, formula weight, gram formula

### Moles and Empirical Formula

Privacy Statement Site Map Contact Us Home Papers Revision Community Blog Games Advertise GCSE: Biology Commerce Statistics A-Level: Physics Economics Home Revision GCSE Moles and Empirical Formula Moles

### GCSE to AS Chemistry

GCSE to AS Chemistry Chemistry is a rewarding yet difficult subject that is highly valued by both employers and higher education establishments. The most challenging part of AS Chemistry is bridging the

### CHEMICAL EQUATIONS and REACTION TYPES

31 CHEMICAL EQUATIONS and REACTION TYPES The purpose of this laboratory exercise is to develop skills in writing and balancing chemical equations. The relevance of this exercise is illustrated by a series

### Formulae, Equations & Formula Mass

St Peter the Apostle High School Chemistry Department Formulae, Equations & Formula Mass N4 & N5 Homework Questions Answer questions as directed by your teacher. National 4 level questions are first followed

### Periodic Table, Valency and Formula

Periodic Table, Valency and Formula Origins of the Periodic Table Mendelѐѐv in 1869 proposed that a relationship existed between the chemical properties of elements and their atomic masses. He noticed

### CHEMICAL REACTIONS AND REACTING MASSES AND VOLUMES

CHEMICAL REACTIONS AND REACTING MASSES AND VOLUMES The meaning of stoichiometric coefficients: 2 H 2 (g) + O 2 (g) 2 H 2 O(l) number of reacting particles 2 molecules of hydrogen react with 1 molecule

### 1.24 Calculations and Chemical Reactions

1.24 Calculations and Chemical Reactions Converting quantities between different substances using a balanced equation A balanced chemical equation tells us the number of particles of a substance which

### USEFUL DEFINITIONS. A substance which cannot be split into anything simpler by chemical means.

Formulae and equations 1 USEFUL DEFINITIONS Element Atom A substance which cannot be split into anything simpler by chemical means. The smallest part of an element that can take part in a chemical reaction.

### USEFUL DEFINITIONS. A substance which cannot be split into anything simpler by chemical means.

1 USEFUL DEFINITIONS Element Atom Molecule A substance which cannot be split into anything simpler by chemical means. The smallest part of an element that can take part in a chemical reaction. The smallest

### IB Chemistry 1 Mole. One atom of C-12 has a mass of 12 amu. One mole of C-12 has a mass of 12 g. Grams we can use more easily.

The Mole Atomic mass units and atoms are not convenient units to work with. The concept of the mole was invented. This was the number of atoms of carbon-12 that were needed to make 12 g of carbon. 1 mole

### Chemistry I: Using Chemical Formulas. Formula Mass The sum of the average atomic masses of all elements in the compound. Units are amu.

Chemistry I: Using Chemical Formulas Formula Mass The sum of the average atomic masses of all elements in the compound. Units are amu. Molar Mass - The mass in grams of 1 mole of a substance. Substance

### TUTORIAL 5-1 HELP. Mass of sodium = 23.0 g/mol x 3 mol = 69.0 g of sodium. Percent mass of sodium = 69.0 g x 100% = 42.

TUTORIAL 5-1 HELP ANSWER TO QUESTION 1 ON TUTORIAL 5-1: Question 1. Find the percent composition by mass of sodium phosphate, Na 3 PO 4. Step 1: Find the molar mass of Na 3 PO 4 (The mass of one mole of

### Unit 2. Molar Mass Worksheet

Unit 2 Molar Mass Worksheet Calculate the molar masses of the following chemicals: 1) Cl 2 8) UF 6 2) KOH 9) SO 2 3) BeCl 2 10) H 3 PO 4 4) FeCl 3 11) (NH 4 ) 2 SO 4 5) BF 3 12) CH 3 COOH 6) CCl 2 F 2

### REDOX REACTIONS AND REDOX EQUATIONS

5 REDOX REACTIONS AND REDOX EQUATIONS DEFINITIONS Most of the reactions and their equations considered so far have been based upon a rearrangement of ions between the components of a mixture. Another very

### Moles, Molecules, and Grams Worksheet Answer Key

Moles, Molecules, and Grams Worksheet Answer Key 1) How many are there in 24 grams of FeF 3? 1.28 x 10 23 2) How many are there in 450 grams of Na 2 SO 4? 1.91 x 10 24 3) How many grams are there in 2.3

### Chemical Calculations

Chemical Calculations 31 Introduction Rules for calculations (a) Always work from first principles - formulas (unless stated) often confuse. (b) Always show all the steps in your working, this reduces

### U3-LM2B-WS Molar Mass and Conversions

U3-LM2B-WS Molar Mass and Conversions Name: KEY 1. The molar mass of chlorine is: 2 x 35.45 g/mol Cl = 70.90 g/mol Cl 2 (Remember that chlorine exists as a diatomic molecule in nature) 2. The molar mass

### Q1. The chart shows the processes involved in the manufacture of nitric acid from ammonia.

Chemistry C2 Foundation and Higher Questions Q1. The chart shows the processes involved in the manufacture of nitric acid from ammonia. (a) Complete the word equation for the reaction that takes place

### Chapter 8 Chemical Quantities

Chapter 8 Chemical Quantities Introductory Info The atomic masses of the elements on the periodic table are in the units. These measurements are based on the mass of the standard isotope of the element,

### INTRODUCTORY CHEMISTRY Concepts and Critical Thinking

INTRODUCTORY CHEMISTRY Concepts and Critical Thinking Sixth Edition by Charles H. Corwin Chapter 9 The Mole Concept by Christopher Hamaker 2011 Pearson Education, Inc. Chapter 9 1 Avogadro s Number Avogadro

### Question Bank in Science Class-IX (Term-II) CONCEPTS

Question Bank in Science Class-IX (Term-II) 3 ATOMS AND MOLECULES CONCEPTS 1 Law of conservation of mass : Mass can neither be created nor can it be destroyed in a chemical reaction 2 Law of constant proportions

### Calculation of Molar Masses. Molar Mass. Solutions. Solutions

Molar Mass Molar mass = Mass in grams of one mole of any element, numerically equal to its atomic weight Molar mass of molecules can be determined from the chemical formula and molar masses of elements

### Stoichiometry Review

Stoichiometry Review There are 20 problems in this review set. Answers, including problem set-up, can be found in the second half of this document. 1. N 2 (g) + 3H 2 (g) --------> 2NH 3 (g) a. nitrogen

### Name Block THE MOLE. Who s Counting Lab. Mole Notes. Mole Calculations. Mixed Mole Conversions. % Comp, Emp, and Molecular Calcuations

Name Block THE MOLE Who s Counting Lab Mole Notes Mole Calculations Mixed Mole Conversions % Comp, Emp, and Molecular Calcuations Mole Notes, Part 1 1. The Mole is just a long word for changing units

### Unit 6 The Mole Concept

Chemistry Form 3 Page 62 Ms. R. Buttigieg Unit 6 The Mole Concept See Chemistry for You Chapter 28 pg. 352-363 See GCSE Chemistry Chapter 5 pg. 70-79 6.1 Relative atomic mass. The relative atomic mass

### Chapter 5 - Molecules and Compounds

Chapter 5 - Molecules and Compounds How do we represent molecules? In pictures In formula In name Ionic compounds Molecular compounds On the course website, you will find a list of ions that I would like

### C2 revision topics 5 and 6

C2 revision topics 5 and 6 To understand heat changes in reactions To be able to describe what controls rates of reactions To be able to explain how to change the rate of a reaction Exothermic Gives out

### IB Chemistry. DP Chemistry Review

DP Chemistry Review Topic 1: Quantitative chemistry 1.1 The mole concept and Avogadro s constant Assessment statement Apply the mole concept to substances. Determine the number of particles and the amount

### Chemical Reactions Chapter 8 Assignment & Problem Set

Chemical Reactions Name Warm-Ups (Show your work for credit) Date 1. Date 2. Date 3. Date 4. Date 5. Date 6. Date 7. Date 8. Chemical Reactions 2 Study Guide: Things You Must Know Vocabulary (know the

### Chapter 5 Basic Chemistry Concepts

Chapter 5 Basic Chemistry Concepts 1 Elements, compounds and molecular weights Table 1 lists some basic information regarding elements that an environmental chemist may encounter. Certain groupings of

### Chem 1100 Chapter Three Study Guide Answers Outline I. Molar Mass and Moles A. Calculations of Molar Masses

Chem 1100 Chapter Three Study Guide Answers Outline I. Molar Mass and Moles A. Calculations of Molar Masses B. Calculations of moles C. Calculations of number of atoms from moles/molar masses 1. Avagadro

### Ch. 10 The Mole I. Molar Conversions

Ch. 10 The Mole I. Molar Conversions I II III IV A. What is the Mole? A counting number (like a dozen) Avogadro s number (N A ) 1 mole = 6.022 10 23 representative particles B. Mole/Particle Conversions

### How much does a single atom weigh? Different elements weigh different amounts related to what makes them unique.

How much does a single atom weigh? Different elements weigh different amounts related to what makes them unique. What units do we use to define the weight of an atom? amu units of atomic weight. (atomic

### Diagnostic/Introductory Activity. Word Search

Diagnostic/Introductory Activity Find any 10 of the first 20 elements. Word Search Q H Z S B N Q J B C N P K M A A M M O O A O E C H E H H U A T L R U X D R E V L G O N I D I O U E I Y I Z N O O S M L

### Metals Topic Test. Part 1: Multiple Choice Choose the best alternative and indicate your response on the answer sheet

Metals Topic Test Part 1: Multiple Choice Choose the best alternative and indicate your response on the answer sheet 1. The chemical equation for the reaction between aluminium and oxygen is: 4Al (s) +

### TOPIC 8. CHEMICAL CALCULATIONS II: % composition, empirical formulas.

TOPIC 8. CHEMICAL CALCULATIONS II: % composition, empirical formulas. Percentage composition of elements in compounds. In Topic 1 it was stated that a given compound always has the same composition by

### Chapter 3. Stoichiometry: Ratios of Combination. Insert picture from First page of chapter. Copyright McGraw-Hill 2009 1

Chapter 3 Insert picture from First page of chapter Stoichiometry: Ratios of Combination Copyright McGraw-Hill 2009 1 3.1 Molecular and Formula Masses Molecular mass - (molecular weight) The mass in amu

### W1 WORKSHOP ON STOICHIOMETRY

INTRODUCTION W1 WORKSHOP ON STOICHIOMETRY These notes and exercises are designed to introduce you to the basic concepts required to understand a chemical formula or equation. Relative atomic masses of

### The Mole Concept and Atoms

Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 4 24 September 2013 Calculations and the Chemical Equation The Mole Concept and Atoms Atoms are exceedingly

### 2. ATOMIC, MOLECULAR AND EQUIVALENT MASSES

2. ATOMIC, MOLECULAR AND EQUIVALENT MASSES INTRODUCTION: EQUIVALENT WEIGHT Since hydrogen is the lightest of all elements, it was chosen as a standard for determination of equivalent weights. On this basis,

Page 1 of 14 Amount of Substance Key terms in this chapter are: Element Compound Mixture Atom Molecule Ion Relative Atomic Mass Avogadro constant Mole Isotope Relative Isotopic Mass Relative Molecular

### Description of the Mole Concept:

Description of the Mole Concept: Suppose you were sent into the store to buy 36 eggs. When you picked them up you would get 3 boxes, each containing 12 eggs. You just used a mathematical device, called

### C2 Chemistry Calculations

C2 Chemistry Calculations You need to know how to carry out several calculations in Additional Science This booklet gives you a step by step guide to carrying out these equations and examples of each one.

### Molar Mass Worksheet Answer Key

Molar Mass Worksheet Answer Key Calculate the molar masses of the following chemicals: 1) Cl 2 71 g/mol 2) KOH 56.1 g/mol 3) BeCl 2 80 g/mol 4) FeCl 3 162.3 g/mol 5) BF 3 67.8 g/mol 6) CCl 2 F 2 121 g/mol

### Calculating Atoms, Ions, or Molecules Using Moles

TEKS REVIEW 8B Calculating Atoms, Ions, or Molecules Using Moles TEKS 8B READINESS Use the mole concept to calculate the number of atoms, ions, or molecules in a sample TEKS_TXT of material. Vocabulary

### The component present in larger proportion is known as solvent.

40 Engineering Chemistry and Environmental Studies 2 SOLUTIONS 2. DEFINITION OF SOLUTION, SOLVENT AND SOLUTE When a small amount of sugar (solute) is mixed with water, sugar uniformally dissolves in water

### Suggested Resources Textbook: Chapter 6 (6.3, 6.4, 6.5 & 6.6)

The Mole Big Picture Ideas: 1. The mole is a unit of count. 2. Using conversion factors, one can convert between mass, moles, particles and volume for a given substance. 3. Empirical data including percent

### SCH 4C1 Unit 2 Problem Set Questions taken from Frank Mustoe et all, "Chemistry 11", McGraw-Hill Ryerson, 2001

SCH 4C1 Unit 2 Problem Set Questions taken from Frank Mustoe et all, "Chemistry 11", McGraw-Hill Ryerson, 2001 1. A small pin contains 0.0178 mol of iron. How many atoms of iron are in the pin? 2. A sample

### Chapter 1: Moles and equations. Learning outcomes. you should be able to:

Chapter 1: Moles and equations 1 Learning outcomes you should be able to: define and use the terms: relative atomic mass, isotopic mass and formula mass based on the 12 C scale perform calculations, including

### Chapter 3 Mass Relationships in Chemical Reactions

Chapter 3 Mass Relationships in Chemical Reactions Student: 1. An atom of bromine has a mass about four times greater than that of an atom of neon. Which choice makes the correct comparison of the relative

### Chapter 4 Chemical Composition

Chapter 4 Chemical Composition 4.1 (a) mole; (b) Avogadro s number; (c) empirical formula; (d) solute; (e) molarity; (f) concentrated solution 4. (a) molar mass; (b) percent composition by mass; (c) solvent;

### Part I: Parts and Meaning of a Chemical Equation:

Chemical Equations Name: Period: Date: Part I: Parts and Meaning of a Chemical Equation: 1) = process by which one or more substances are changed into one or more different substances (atoms are rearranged)

### Chemistry Assessment Unit AS 1

New Specification Centre Number 71 Candidate Number ADVANCED SUBSIDIARY (AS) General Certificate of Education January 2010 Chemistry Assessment Unit AS 1 assessing Basic Concepts in Physical and Inorganic

### 2. Draw the Bohr-Rutherford diagrams for the following Ions: S 2-, Al +3, Li +1, P -3

1. Complete the following table: ATOMIC STRUCTURE Name Symbol # protons # neutrons # electrons Net charge Sodium ion Na +1 +1 Oxygen atom Gold ion +3 C Cl -1 Cesium ion +1 12 +2 16-2 18 +1 10 0 Ba +2 Helium

### National 4/5 Chemistry. Unit 1c - Chemical Changes and Structure

National 4/5 Chemistry Unit 1c - Chemical Changes and Structure Kirkcaldy High School 2013/2014 Contents Formation of ions (N4*)...1 Formation of ions (N4*)...3 Ionic bonding (N4*)...4 Writing formulae

### Section 6.6: The Composition of Unknown Compounds

Section 6.6: The Composition of Unknown Compounds Tutorial 1 Practice, page 286 1. Given: = 4.60 g ; m N = 1.40 g Required: percentage of each element: % N; % O Step 1. Use the percentage formula to calculate

### One element, usually a metal, replaces another element in a compound. This forms a new compound and leaves behind a new free element!

124 SINGLE REPLACEMENT REACTIONS One element, usually a metal, replaces another element in a compound. This forms a new compound and leaves behind a new free element! example: Copper loses electrons, goes

### Using the Periodic table: Main Group. Using the Periodic Table:Transition Group. Binary Compounds: Names, Formulae

Using the Periodic table: Main Group Main Group Elements 1 Using the Periodic Table:Transition Group Transition Metals Form various cations by loss of electrons e.g. Fe 2+ / Fe 3+, Cu + / Cu 2+ Cr 2+ /

### Lecture Notes Chemistry E-1. Chapter 3

Lecture Notes Chemistry E-1 Chapter 3 http://inserbia.info/news/wp-content/uploads/2013/05/tamiflu.jpg http://nutsforhealthcare.files.wordpress.com/2013/01/tamiflu-moa.jpg The Mole A mole is a certain

### Chemical Proportions in Compounds

Chapter 6 Chemical Proportions in Compounds Solutions for Practice Problems Student Textbook page 201 1. Problem A sample of a compound is analyzed and found to contain 0.90 g of calcium and 1.60 g of

### Chemical Calculations: Formula Masses, Moles, and Chemical Equations

Chemical Calculations: Formula Masses, Moles, and Chemical Equations Atomic Mass & Formula Mass Recall from Chapter Three that the average mass of an atom of a given element can be found on the periodic

### CHAPTER 3 STOICHIOMETRY OF FORMULAS AND EQUATIONS

CHAPTER 3 STOICHIOMETRY OF FORMULAS AND EQUATIONS FOLLOW UP PROBLEMS 3.1A Plan: The mass of carbon must be changed from mg to g. The molar mass of carbon can then be used to determine the number of moles.

### Monday, October 15th. Today: Chapter Frequency: BB Pearson Education, Inc. Chapter 6, Section 1 1

Today: Chapter 6.1-6.4 Monday, October 15th Frequency: BB 2013 Pearson Education, Inc. Chapter 6, Section 1 1 Chemical Change- Section 6.1 A chemical change occurs when a substance is converted into one

### CHAPTER 3 Calculations with Chemical Formulas and Equations. atoms in a FORMULA UNIT

CHAPTER 3 Calculations with Chemical Formulas and Equations MOLECULAR WEIGHT (M. W.) Sum of the Atomic Weights of all atoms in a MOLECULE of a substance. FORMULA WEIGHT (F. W.) Sum of the atomic Weights

### More on ions (Chapters 2.1 and )

More on ions (Chapters 2.1 and 3.5 3.7) Ion: an atom or molecule that has a net electrical charge. Examples: Na + (sodium ion), Cl - (chloride), NH 4 + (ammonium). Anion: a negative ion, formed when electrons

### Solution. Practice Exercise. Concept Exercise

Example Exercise 9.1 Atomic Mass and Avogadro s Number Refer to the atomic masses in the periodic table inside the front cover of this textbook. State the mass of Avogadro s number of atoms for each of

### Balancing Chemical Equations

Balancing Chemical Equations Academic Success Center Science Tutoring Area Science Tutoring Area Law of Conservation of Mass Matter cannot be created nor destroyed Therefore the number of each type of

### Test 3 Formula and math of formula review. 2. The oxide of metal X has the formula XO. Which group in the Periodic Table contains metal X?

Name: Sunday, November 04, 2007 Test 3 Formula and math of formula review 1. Which is an example of a binary compound? 1. acetic acid 3. potassium hydroxide 2. nitric acid 4. potassium oxide 2. The oxide

### MOLECULAR MASS AND FORMULA MASS

1 MOLECULAR MASS AND FORMULA MASS Molecular mass = sum of the atomic weights of all atoms in the molecule. Formula mass = sum of the atomic weights of all atoms in the formula unit. 2 MOLECULAR MASS AND

### CHEMICAL INDUSTRY HOMEWORK

CHEMICAL INDUSTRY HOMEWORK 1. Which of the following can be classed as a raw material in the chemical industry? A. Iron ore B. Ammonia C. Methanol D. Petrol 2. Which of the following costs would be classed

### Chemistry AS90171 Describe chemical reactions

Chemistry AS90171 Describe chemical reactions This achievement standard involves the description of chemical reactions, including the carrying out of calculations. Achievement Merit Excellence Describe

### Chapter 4. Chemical Composition. Chapter 4 Topics H 2 S. 4.1 Mole Quantities. The Mole Scale. Molar Mass The Mass of 1 Mole

Chapter 4 Chemical Composition Chapter 4 Topics 1. Mole Quantities 2. Moles, Masses, and Particles 3. Determining Empirical Formulas 4. Chemical Composition of Solutions Copyright The McGraw-Hill Companies,

### CHEMISTRY. SCIENCE Paper 2. SECTION I (40 Marks)

CEMISTRY SCIENCE Paper 2 (Two hours) Answers to this Paper must be written on the paper provided separately. You will not be allowed to write during the first 15 minutes. This time is to be spent in reading

### Chemistry Department. Standard Grade Homework Exercise Booklet

Chemistry Department Standard Grade Homework Exercise Booklet Instructions The purpose of this booklet is to help you revise previous work and improve your knowledge & understanding, to maximise your success

### Chemical Proportions in Compounds

Chapter 3 Chemical Proportions in Compounds Note to teacher: You will notice that there are two different formats for the Sample Problems in the student textbook. Where appropriate, the Sample Problem

### TOPIC 8. CHEMICAL CALCULATIONS II: % composition, empirical formulas.

TOPIC 8. CHEMICAL CALCULATIONS II: % composition, empirical formulas. Percentage composition of elements in compounds. In Topic 1 it was stated that a given compound always has the same composition by

### Electrolysis This is when an electric current passes through an electrolyte.

Conductors Metals and graphite are the only solids which conduct electricity, but no chemical change is involved. Liquid (melted) metals also conduct, but again there is no chemical change. Electrolytes

### Chapter 7: Chemical Equations. Name: Date: Period:

Chapter 7: Chemical Equations Name: Date: Period: 7-1 What is a chemical reaction? Read pages 232-237 a) Explain what a chemical reaction is. b) Distinguish between evidence that suggests a chemical reaction

### Unit 5 Chemical Quantities & The Mole

Unit 5 Chemical Quantities & The Mole Molar mass is the mass of one mole of a substance. Molar Mass Other names for molar mass include *formula mass *gram formula mass *molecular weight Molar Mass One

### Mole Notes.notebook. October 29, 2014

1 2 How do chemists count atoms/formula units/molecules? How do we go from the atomic scale to the scale of everyday measurements (macroscopic scale)? The gateway is the mole! But before we get to the

### CHAPTER 8: CHEMICAL COMPOSITION

CHAPTER 8: CHEMICAL COMPOSITION Active Learning: 1-4, 6-8, 12, 18-25; End-of-Chapter Problems: 3-4, 9-82, 84-85, 87-92, 94-104, 107-109, 111, 113, 119, 125-126 8.2 ATOMIC MASSES: COUNTING ATOMS BY WEIGHING