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These include all the PH reactions, indicators, Cations, Anions, gases and compound tests which are necessary to memorise for the double award chemistry gcse edexcel curriculum
carbonates test
By adding an acid (HCl) and testing the gas produced for CO2
Products of a reaction between a carbonate and an acid
A salt, water, carbon dioxide
CO2 test
Lime water turns from clear to milky
What is a precipitate
an insoluble solid substance formed from a solution
What is the characteristic of acidic solutions
They are hydrogen ions/ proton donors
What is the characteristic of basic solutions
They are hydroxide (OH-) donors/ can absorb Hydrogen ions
Name the main four pH indicators
Universal indicator
Litmus paper
Phenolphethalein
Methyl orange
How does litmus paper indicator work
-Acidic solutions turn orange
-Neutral solutions turn purple
-Alkaline solutions turn blue
It can not show the strength of these solutions
How does Phenolphthalein indicator work
Turns from colourless in acids and neutrals to bright pink in alkalis
How does Methyl orange indicator work
Turns from red in acids to yellow in alkalis
Products of a reaction between a metal and an acid
Salt + Hydrogen
What is the test for sulfates?
Nitric acid + Barium Chloride solution, BaCl2 (Can be any acid other than sulphuric).
A positive test forms a white precipitate
Why is nitric acid added to the test for sulfates and halides?
To react with traces of carbonate or sulfide ions so that they may interfere with the results
What are halides
Ions of halogens
What is the test for halides
Nitric acid + silver nitrate
What is the result of a positive chloride test
A white precipitate (Silver chloride, AgCl)
What is the result of a positive bromide test
A cream precipitate (Silver bromide, AgBr)
What is the result of a positive Iodine test
A yellow precipitate (Silver Iodide, AgI)
What reactants create soluble salts
An acid + an insoluble base
What is the difference between a base and an alkaline
An alkaline is a base which can be disolved in water
Describe the procedure of forming a soluble salt
The acid is heated
The insoluble base is added to the acid in excess
The solution is filtered to remove excess solid
The solution is slowly heated to evaporate some of the water
The solution is left to cool and the salt crystalises
Filter of the solid crytals and let them dry
Give an example reaction equation which would produce a soluble salt
Copper oxide (CuO) + Sulfuric acid (H2SO4) reacts to form Copper sulfate (CuSO4) + water (H2O)
What is the test for water
Dehydrated copper sulfate crytals turn from white to blue in the presence of water
What is the positive test for Lithium ions (Li+)
Red flames
What is the positive test for Sodium ions (Na+)
Yellow flames
What is the positive test for Potassium ions (K+)
Lilac flames
What is the positive test for Calcium ions (Ca2+)
Orange-red flames
What is the positive test for Copper ions (Cu2+)
Blue-green flames
How is the flame test for metal cations conducted?
A platinum or nichrome wire piece is cut
The wire is dipped in HCl acid to clean it
It is then dipped in the sample metal and held over the blue part of the bunsen flame
The wire can be cleaned and used again
what is the cations coloured precipitate test
Adding a few drops of sodium hydroxide (NaOH) to a metal ion sample which should form a colourful precipitate
What is the result of a Copper II (Cu2+) test?
A blue precipitate
What is the result of an Iron II (Fe2+) test?
A sludgy green precipitate
What is the result of an Iron III (Fe3+) test?
A reddish brown precipitate
What is the result of an ammonium ion test?
Red litmus paper turns blue
How is an ammonium ion test conducted?
A few drops of Sodium hydroxide (NaOH) are added to an ammonium solution
Damp litmus paper is held over the test tube to pick up on ammonia gas
What is the test for chlorine gas?
Damp blue limus paper turns white
What is the test for Oxygen gas?
It relights a glowing splint
What is the test for Hydrogen gas?
It burns with a squeaky pop
What is the test for ammonia gas?
Damp blue litmus paper turns red
Results of a reaction between an acid and a metal hydroxides
A salt + water
Results of a reaction between an acid and a metal oxides
A salt + water
What is the name of the precipitate formed when limewater reacts with CO2
Calcium carbonate
Note 
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