learning and eaching resources on ractical for …

LEARNING AND TEACHING RESOURCES ON PRACTICAL FOR CHEMISTRY AND COMBINED SCIENCE (CHEMISTRY PART)

Sophia SL Cheng Science Education Section, EDB

Resource materials Examples of experiments for SBA tasks

1. Inquiry-based Chemistry Experiments (CUHK & EDB, 2002)

2. Learning and Teaching Activities for the Revised Sixth Form Chemistry Curriculum (EDB, 2005)

1. • Identification of white solids

2. • Determination of the heat of combustion of alcohols • Relative molecular mass of butane • Concentration effect and reaction rate

3. Investigative Study in Chemistry – Exemplars of Learning and Teaching Activities (HKUST, EDB & HKEAA, 2009)

3. • Getting copper from its ore • Making your own acid-base indicator • How to make it hot?

4. Workshops on Miniature Practical Chemistry (HKUST & EDB, 2008)

4. • Synthesis of isoamyl acetate (banana oil) • Isolation of chlorophyll from spinach

5. Resource Book for Sixth-Form Practical Chemistry (CUHK, EDB & HKEAA, 2004)

5. • Calcium carbonate in eggshell (Inquiry-based) • Alcohol breath analysis

6. Workshops on Implementing Microscale Chemistry Experiments (HKBU & EDB, 2008-2010)

6. • Reactivity series of magnesium, zinc and copper • Chemical cells / fuel cell

7. Experiments of Microscale Analytical Chemistry and Microscale Organic Chemistry for Secondary Schools (HKUST & EDB, 2011)

7. • Microscale separation of components in a mixture

ASSESSMENT OBJECTIVES (SECTION 5.3 OF C&A GUIDE)

2013 HKDSE Paper I 4(d), (e)

2013 HKDSE Chemistry Examination Report

4(d) (ii) In general, candidates were weak inhandling chemical calculations. Some were not able to demonstrate an understanding that H2C2O4 (aq) reacts with NaOH(aq) in 1:2 mole ratio.

(e) (i) Some candidates wrongly mentioned that the residual acid affects the concentration of the acid in the conical flask instead of its volume.

PRACTICAL ACTIVITIES FOR CHEMISTRY AND COMBINED SCIENCE (CHEMISTRY PART)

Acids and Bases pH Curve (with the use of datalogger)

Mole Concept and Stoichiometry Decomposition of Baking Soda Determining the Stoichiometry of Reaction Between

SBAClO- and S2O32- / OH-

Rate of Reaction Reaction of Phenolphthalein in NaOH solution (with

SBAthe use of datalogger) Catalysts for the Decomposition of H

SBA 2O2 (with the

use of datalogger) Elephant Toothpaste – Effect of Catalyst on

Reaction Rate

Microscopic World II Evaporation and Intermolecular Attractions Preparation of “Slime”

SBA

TO STUDY HOW CONCENTRATION AFFECTS THE RATE OF A REACTION USING DATALOGGER

pH of solution is 8.2 – 12: H2Ph(aq) + 2OH(aq) → Ph2-(aq) + 2H2O(l) (fast)

phenolphthalein colourless pink

pH of solution is above 12: Ph2-(aq) + OH-(aq) PhOH3-(aq) (slow)

pink

colourless

SAMPLE ABSORBANCE – TIME CURVES

EVAPORATION AND INTERMOLECULAR ATTRACTIONS

To study temperature changes caused byevaporation of the following liquids: ethanol, propan-1-ol, butan-1-ol, pentane, hexane

To relate temperature changes to the strength of theintermolecular forces of the liquid

THE EXPERIMENTAL SET-UP

SAMPLE RESULT

Substance Temperature decrease (oC)

Ethanol 9.1 Propan-1-ol 6.4 Butan-1-ol 3.3 Pentane 16.2 Hexane 13.9

Factors affecting intermolecular forces: • Molecular masses • Hydrogen bond

Compare the intermolecular forces among: • Alkanes • Alcohols • Pentane and butan-1-ol

INVESTIGATION - CATALYSTS FOR THE DECOMPOSITION OF HYDROGEN PEROXIDE

Objectives: To investigate the effect of the use ofcatalyst on reaction rate and compare the effectivenessof different catalysts on the decomposition of H2O2

Possible catalysts: KI(aq) / MnO2(aq) / Celery / Pig Liver ….

THE EXPERIMENT

to data logger OR

to gas syringe Plant extract (potato)

One of the following catalysts: Powdered manganese(IV) oxide (MnO2) Fresh potato extract Fresh celery extract A small piece of fresh pig liver 1 M Fe(NO3)3(aq) / FeCl3(aq) Adding catalyst into 100 cm3 1 M KI(aq) H2O2(aq)

EXPERIMENT RESULT

http://edblog.hkedcity.net/nsschem

http://minisite.proj.hkedcity.net/edbosp-sci/eng/home.html

References and resources for Chemistry, Science Education Section, EDB (http://www.edb.gov.hk/en/curriculum-development/kla/science-edu/ref-and-resources/index.html)

CHEMISTRY EXPERIMENTAL TECHNIQUES

http://minisite.proj.hkedcity.net/safetyonline/eng/index.html

NSS UNDERSTANDING AND INTERPRETING THE CHEMISTRY AND COMBINED SCIENCE (CHEMISTRY PART) CURRICULA (REFRESHED) (CDI020150195)

Date: 10/11/2014 (Monday) Time: 2:00pm – 5:00pm Venue: EDB Kowloon Tong Education Services Centre

CONTACT INFORMATION

Dr Raymond Fong

Tel: 3698 3436

Email: raymondfong@edb.gov.hk

Tim Tse

Tel: 3698 3438

Email: timbltse@edb.gov.hk

Sophia Cheng

Tel: 3698 3439

Email: sophiaslcheng@edb.gov.hk