IC5.3.4 Percentage masses from formulae © Oxford University Press Percentage masses from formulae.

Slides:



Advertisements
Similar presentations
Calculations What you need to know: Relative formula mass Empirical formula % composition by mass Use balanced equations to calculate masses of reactants.
Advertisements

Ionic Compound Naming What are transition metals? How are they different from metalloids? Find 6 compounds that start with a transition metal What patterns.
Aim: How to calculate Percent Composition
Chapter 7 – The Mole and Chemical Composition
Mole Notes.
2.00 ECS 1.00 IonsMass Finding the Empirical Formula of a Compound © Chemworks.
Percentage Composition by mass and empirical formula.
Calculating Percent Composition Mrs. Page 10 th Chemistry.
Percent Composition. What is Percent Composition?  The percent composition by mass of a compound represents the percent that each element in a compound.
STANDARD GRADE CHEMISTRY CALCULATIONS Calculation of percentage composition. Percentage composition allows us to calculate the percentage of any element.
Lesson 25 Percent Composition
The Point of Today: Learn about Polyatomic Ions. At the end of today you will be able to: 1. Make compounds using Polyatomic Ions. 2. Name compounds that.
REVISION C4 1 st Half! (H) An acid can be neutralised by adding a ______ or an ______ to it. An _______ is a soluble _______. An alkali can be neutralised.
Modern Chemistry Chapter 7 Chemical Formulas and Chemical Compounds
Aim: How can we calculate percent composition of a compound? Do Now: 1.Take out a calculator and reference tables. 2.What is the gram formula mass of C.
The Structure of Matter What are the 3 types of chemical bonds? Describe each.
Chemical Formulas and Moles. Example: 1.water (C) – every molecule of water contains 2 atoms of hydrogen & one atom of oxygen - 2 molecules of H 2 O would.
Moles and Stoichiometry Chapters 11 & 12. Counting Particles Particles are counted in moles Types of representative particles Atoms- smallest unit of.
Counting Atoms Chapter 9. MOLE?? Moles of Particles In one mole of a substance, there are 6 x particles.
STANDARD GRADE CHEMISTRY CALCULATIONS Calculation of empirical composition. The formula of compounds can be determined by experiment. The empirical formula.
IIIIII Suggested Reading: Pages Chapter 7 sec 3 & 4.
Percentages How do you calculate your percentage score in a test if you correctly answered 34 out of 47 questions? Answer: 33/47 x 100/1 = ? If 18 out.
Molar Mass Practice: Molar Mass Practice: 1. Find the molar mass of ammonium sulfate (also called the formula mass): 2. Find the molar mass of copper (II)
Calderglen High School
Molar Mass & Molarity. Molar Mass Mass in grams of one mole of an element or compound. Numerically equal to the atomic weight of the element or the sum.
#32 A compound is formed when 9.03 grams Mg combines with
Percent Composition. What is it? The percent composition by mass of a compound represents the percent that each element in a compound contributes to the.
Stoichiometry Chapter 11 & 12. I. Things you should remember From the Moles Unit: Identify particles as atoms, molecules (mc), and formula units (fun)
Percent Composition. Percent by mass of a particular element in a compound % Element = Mass of Element x 100 Mass of Compound.
Percent Composition Percent by mass of an element in a compound.
Aim: How to calculate Percent Composition  DO NOW: 1. What is the number of moles of potassium chloride present in 148 g? 2. What is the molar mass of.
Got Mole Problems?.
J OURNAL #72 How many moles of compound are there in 6.00g of ammonium sulfate? How many molecules are there in 20.0g sulfuric acid?
Balancing Chemical Equations. Balanced Equation Atoms can’t be created or destroyed Atoms can’t be created or destroyed Law of Conservation of Mass Law.
We’ll go over this example in video form.. We’re asked to name the compound with the formula NH 4 NO 3 Name the compound with the formula NH 4 NO 3.
Chapter Three Mass Relationships in Chemical Reactions.
IC5.1.4 Calculations © Oxford University Press Calculations.
IC5.2.3 Mole calculations © Oxford University Press Mole calculations.
IC5.3.3 Masses from experimental data © Oxford University Press Masses from experimental data.
CHEMISTRY NOTES Polyatomic Ions. What is the formula for….  Iron (III) chloride  FeCl 3  Copper (II) nitride  Cu 3 N 2  Tin (II) Oxide  SnO.
Percent Composition. Percent Composition by Mass – If you want to know what percentage of a compounds’ mass is contributed to by each element present.
You’re going to need to get your pens ready for this one! Calculations in chemistry And quickly finishing off metallic structures.
Balancing Chemical Equations
The Mathematics of Formulas and Equations
Calderglen High School
Percent Composition.
The Calculation of Formula Weight !!!
Aim: How to calculate Percent Composition
Percent Composition Calculations
Balancing Chemical Equations
Chapter 7 – Chemical Formulas and Chemical Compounds
Mole problems with compounds
Percent Composition.
Calderglen High School
To find a percent: part X 100
Percent Composition.
Percent Composition.
To find a percent: part X 100
Relative Formula Mass This is the total mass of the sum of all the relative atomic masses of the elements in a compound.
Unit 2: Chemical Nomenclature
Vocabulary Percent Composition -
Unit F Tutorial 2: Chemical Formulas and Formula Mass
Percentage Composition
Percent Composition.
POLYATOMIC COMPOUNDS.
Percent Composition Unit 5.
Percent Composition.
Presentation transcript:

IC5.3.4 Percentage masses from formulae © Oxford University Press Percentage masses from formulae

IC5.3.4 Percentage masses from formulae © Oxford University Press The formula of a compound, and the relative atomic masses of the elements it contains, can be used to calculate percentage masses.

IC5.3.4 Percentage masses from formulae © Oxford University Press Ammonium nitrate, NH 4 NO 3, is used as an artificial fertiliser. Suppose you wanted to calculate the percentage by mass of nitrogen in ammonium nitrate. Follow these three steps to see how it’s done…

IC5.3.4 Percentage masses from formulae © Oxford University Press NH 4 NO 3 A r of N = 14, A r of H = 1, A r of O = 16 1.Calculate the relative formula mass of the compound using the relative atomic masses.  M r of NH 4 NO 3 = 14 + (4 × 1) (3 × 16) = 80

IC5.3.4 Percentage masses from formulae © Oxford University Press NH 4 NO 3 A r of N = 14, A r of H = 1, A r of O = 16 2.Multiply the relative atomic mass of the element in the question by the number of its atoms in the compound.  Mass of N = 2 × 14 = 28 (notice that N appears twice in the formula)

IC5.3.4 Percentage masses from formulae © Oxford University Press NH 4 NO 3 A r of N = 14, A r of H = 1, A r of O = 16 3.Work out the percentage by mass of nitrogen in ammonium nitrate using the numbers from steps 1 and 2.  Percentage of N in NH 4 NO 3 = 28/80 × 100% = 35%

IC5.3.4 Percentage masses from formulae © Oxford University Press Now use these A r values to help you to answer the questions: H = 1, O = 16, Na = 23, S = 32, Cu = Calculate the percentage by mass of sodium in sodium hydroxide, NaOH.  M r of NaOH = = 40  A r of Na = 23  Percentage of Na in NaOH = 23/40 × 100% = 57.5%

IC5.3.4 Percentage masses from formulae © Oxford University Press A r values : H = 1, O = 16, Na = 23, S = 32, Cu = Calculate the percentage by mass of oxygen in copper sulfate, CuSO 4.  M r of CuSO 4 = (4 × 16) =  Mass of O = (4 × 16) = 64  Percentage of O in CuSO 4 = 64/159.5 × 100% = 40%