Analysis by Mass Chapter 2

Unit 3  Consists of Area of Study 1  Chemical analysis  Area of Study 2  Organic Chemical Pathways  Each area of study will take about a term  Though hopefully quicker  There are 3 sacs and 1 exam a semester

The Exam  This is what you are working towards.  The chemistry unit 3 exam is on June 10 th  It consists of 15 minutes reading time and 1.5 hours writing time.  It is made up of 20 multiple choice questions and about 8 short answer questions  You get a data booklet and are allowed a scientific calculator (no graphics)

The S.A.C.s  There are 3 S.A.C.s in unit 3  The first one is in Area of Study 1  This is the extended experimental investigation (E.E.I.)  This will begin in week 6 (Mar 9) and will take about 3 weeks.  It consists of 3 practical activities, questions to be answered on each prac, risk assessments to be written for each prac, a report to be written on all 3 pracs.  The E.E.I. will be on the analysis of the composition of lawn fertiliser

 The next two S.A.C.s will be in area of study 2.  One will be a practical report  One will be a response to written stimulus The S.A.C.s

Significant Figures  All your answers to calculations this year must be to significant figures.  Look at page 470 (Appendix 1)  A zero that comes before integers in not significant but a zero that comes after an integer is.  Significant figures is where your final value you calculate is only as precise as your least precise piece of data.  Meaning your answer has to use the lowest amount of significant figures that the question contains.

So lets review the holiday homework  What is the difference between qualitiative and quantitative analysis?  What are some analysis techniques and why might we use them?  Look at page 12 worked example and answer question 1 on page 12.  Remember % by mass is:  Do questions 3 and 5 page 12 Final mass of sample Initial mass of sample x 100

Empirical Formula  Simplest whole number ratio of the atoms present in the compound Step 1: Measure the mass (m) of each element in the compound Step 2: Calculate the amount in mole (n) of each element in the compound Step 3: Calculate the simplest whole number ratio of moles of each element in the compound Step 4: Determine the empirical formula of the compound

Molecular Formula  Gives the actual number of atoms of each element present in a molecule of compound  One unit can be the empirical formula molecular mass = molar mass of compound molar mass of one unit

Stoichiometry  What equations do we know??  Page 21  Lets do question 21 together.

Homework  P.12 Q 1, 3, 5  P.25 Q 21, 25, 27, 29, 31  P. 26 Q 36, 41, 42, 44