Please read these tests for the cations and anions for your Alternative paper 4.
Test for cations:
Add Dilute sodium hydroxide solution. Precipitate form, add aqueous ammonia solution or NaOH solution to see if the precipitate dissolves.
Observation for the following cations:
Fe2+ - Dark Green ppt
Fe3+ - Brown ppt
Cu2+ - Blue ppt
Ca2+, Mg2+ - White ppt - Do not dissolve in excess Ammonia solution or NaOH solution.
Al3+, Zn2+, Pb2+ - White ppt - Dissolve in excess.
Test for Anions:
Carbonate : Add dilute acid : Observation: bubbles/ effervescene - Test for the gas using limewater.
Sulphate: Add acid followed by barium chloride/ nitrate solution. (Any soluble barium salt + any soluble sulphate forms a white dense barium sulphate precipitate. ) then add dilute acid again. Observation: White ppt, insoluble in excess
Nitrate: Boil the nitrate in sodium hydroxide solution and add fine aluminium powder or aluminium foil. Observation: Ammonia gas is given off, (pungent smell)
Test for ammonia gas to confirm is that litmus paper turn from red to blue.
Test for halogens: Always add dilute nitric acid first, then silver nitrate solution.
Chloride: add dilute nitric acid and silver nitrate solution. Observation: white precipitate Bromide: add dilute nitric acid and silver nitrate solution. Observation: Cream ppt
Iodide: dilute nitric acid and silver nitrate solution. Observation : yellow ppt
Test for gases
Test for Carbon Dioxide: Limewater : Observation: turns limewater milky
Test for oxygen gas: Glowing split: Observation: Relights glowing splint
Test for hydrogen gas: Burning split. Observation: "POP" sound
Test for sulphur dioxide: potassium dichromate(VI) solution, observation: turns the solution from orange to green.
Test for ammonia gas : damp red litmus paper. Observation: Turns red litmus paper blue.
Test for chlorine: damp blue litmus. Observation: bleach the litmus paper
Saturday 9 October 2010
Thursday 30 September 2010
End of year examination topics.
I have listed the topics for your easily references for revision. Do your revision and please work hard. If there is any questions, you can always look for me in the office or email me at singkasing@yahoo.com.
Topics that are included in the end-of-year examination 2010
1. Kinetic particle theory- describe solid, liquid and gaseous state of matter, the movement of particles, diffusion.
2. Atomic structures – know what proton number, neutron numbers and electron numbers are, should be able to know which is the proton and neutron number of the the element in the periodic table, define what is isotopes and explain how the elements are isotopes.
3. Describe the difference between elements, mixtures and compounds
4. Molecular compound and giant ionic lattice, compare the structures such as diamond and graphite, compare the structures of the molecular compounds. Also deduce the properties and bonding of the giant ionic lattice and molecular compound.
5. Ionic bonding – how ionic bonding is formed, between metal and non metal, draw the structure of ionic compound. ( make sure you have the brackets and charges) Deduce the formula of ionic compound, properties of ionic bonding
6. Covalent bonding – how covalent bonding is formed- the sharing of electrons between two non-metal. Draw the dot and cross diagram for the covalent compounds, properties of covalent bonding.
7. metallic bonding- metal as a lattice of positive ions in a sea of electrons, properties of metallic bonding.
8. Writing Chemical formulae, writing the formulae of ions, both monoatomic ions (which are found in the periodic table) and polyatomic ions (such as sulphate, nitrate, carbonate)
9. Writing chemical equations, balance chemical equation, writing Ionic equations (including state symbols)
10. Mole concept, calculations involving moles, mass, Mr, Ar, volume, concentration, % mass, empirical formula, molecular formula, % yield, % purity.
11. Experimental techniques – apparatus, method of purification.
12. Acid and bases: characteristics of acids and bases, neutralization, preparation of salts (soluble and insoluble salt) and oxides (acidic oxides, basic oxides and amphoteric oxides)
Ms Ping Sing
Topics that are included in the end-of-year examination 2010
1. Kinetic particle theory- describe solid, liquid and gaseous state of matter, the movement of particles, diffusion.
2. Atomic structures – know what proton number, neutron numbers and electron numbers are, should be able to know which is the proton and neutron number of the the element in the periodic table, define what is isotopes and explain how the elements are isotopes.
3. Describe the difference between elements, mixtures and compounds
4. Molecular compound and giant ionic lattice, compare the structures such as diamond and graphite, compare the structures of the molecular compounds. Also deduce the properties and bonding of the giant ionic lattice and molecular compound.
5. Ionic bonding – how ionic bonding is formed, between metal and non metal, draw the structure of ionic compound. ( make sure you have the brackets and charges) Deduce the formula of ionic compound, properties of ionic bonding
6. Covalent bonding – how covalent bonding is formed- the sharing of electrons between two non-metal. Draw the dot and cross diagram for the covalent compounds, properties of covalent bonding.
7. metallic bonding- metal as a lattice of positive ions in a sea of electrons, properties of metallic bonding.
8. Writing Chemical formulae, writing the formulae of ions, both monoatomic ions (which are found in the periodic table) and polyatomic ions (such as sulphate, nitrate, carbonate)
9. Writing chemical equations, balance chemical equation, writing Ionic equations (including state symbols)
10. Mole concept, calculations involving moles, mass, Mr, Ar, volume, concentration, % mass, empirical formula, molecular formula, % yield, % purity.
11. Experimental techniques – apparatus, method of purification.
12. Acid and bases: characteristics of acids and bases, neutralization, preparation of salts (soluble and insoluble salt) and oxides (acidic oxides, basic oxides and amphoteric oxides)
Ms Ping Sing
Wednesday 1 September 2010
Festive holiday Homework
Dear Year 9 H, A and M students.
You have grouped yourself into a group of four or five and there are six groups in a class. You have also received a printed copy of your festive holiday homework. Each group will have different tasks. I will pass put the task of the groups on the blog as well later on.
I hope you will all enjoy doing the homework over the holiday ( something different at least), please discuss and work together as a group. Due date for the work is the second week after the school reopen. and after the holiday, we will need to work extra hard and will be very hectic and lots of extra classes, be prepared.
Lastly happy holiday.
Miss Ping Sing
You have grouped yourself into a group of four or five and there are six groups in a class. You have also received a printed copy of your festive holiday homework. Each group will have different tasks. I will pass put the task of the groups on the blog as well later on.
I hope you will all enjoy doing the homework over the holiday ( something different at least), please discuss and work together as a group. Due date for the work is the second week after the school reopen. and after the holiday, we will need to work extra hard and will be very hectic and lots of extra classes, be prepared.
Lastly happy holiday.
Miss Ping Sing
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