Obtaining crystals..
Saturated solution --> Boil --> cool --> Crystals!
Crystallisation
Year 9 Chemistry 2012
Year 9 G,H,T MSPSBS Chemistry Blog
Questions?
Any questions, email me at singkasing@yahoo.com or look for me in the departmental office!!!!! Don't be shy, if something is difficult, it does not mean that you should stop learning, instead, try harder, eventually you will succeed.
Monday, 2 April 2012
Wednesday, 15 February 2012
Answers
Dear Students,
Please click on the link below for the answers.
Write all your answers in red pen!
Thanks!!!!!
Answers to Elements, Molecules, Compound Exercises
Please click on the link below for the answers.
Write all your answers in red pen!
Thanks!!!!!
Answers to Elements, Molecules, Compound Exercises
Monday, 7 February 2011
General Rules in determining the Oxidation State/ Oxidation Number
Sunday, 9 January 2011
REACTIVITY OF METALS WITH WATER. STEAM AND ACID
SUMMARY OF THE REACTIONS OF METALS & REDUCTION OF METAL OXIDES WITH HYDROGEN AND CARBON
Click on the link below to download the document, you could either print it out, or write it on a piece of paper and put it into your file!!!!
SUMMARY OF THE REACTIONS OF METALS & REDUCTION OF METAL OXIDES WITH HYDROGEN AND CARBON
OR Just click on the image below.
Click on the link below to download the document, you could either print it out, or write it on a piece of paper and put it into your file!!!!
SUMMARY OF THE REACTIONS OF METALS & REDUCTION OF METAL OXIDES WITH HYDROGEN AND CARBON
OR Just click on the image below.
Saturday, 9 October 2010
Alternative paper 4
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
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
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