2(h) f + g required! Flashcards
State the test for Hydrogen(gas)
Lighted splint held to mouth of a tube with oxygen. Squeaky pop. 2H2 + O2»_space; 2H2O
State the test for Oxygen(gas)
Glowing splint relights.
State the test for Carbon Dioxide(gas)(2)
Bubbled through limewater, limewater turns milky/cloudy.
Calcium Carbonate is formed, which is insoluble.
State the test for Chlorine(gas)
Damp litmus paper or universal indicator paper put into test tube. Chlorine bleaches damp litmus paper or universal indicator. Red then white.
State the test for Ammonia(gas)
NH3, turns universal indicator paper or red litmus paper blue.
State the test for water?(2)
Anhydrous copper sulfate. Water turns it from white to blue. Works for anything contains H2O.
CuSO4(s) + 5H2O » CuSO4-5H2O(s)
How is a flame test prepared?
Platinum or nichrome wire dipped into concentrated HCl then into salt that needs testing.
Result of a Lithium flame test?
Red Flame shows lithium ions.
Result of a sodium flame test?
Yellow Flame shows sodium ions.
Result of a potassium flame test?
Lilac flame shows potassium ions.
Result of a calcium flame test?
Orange-Red flame shows Calcium ions.
Result of a copper(II) flame test?
Blue-Green flame shows copper(II) ions.
How is a cation test with Sodium Hydroxide solution prepared?
Dissolve the salt in pure water and put some in a test tube. Add the same amount of volume of dilute sodium hydroxide solution.
What is the result of a copper(II) with Sodium Hydroxide test?(2)
Blue precipitate is formed in presence of copper(II) ions.
Cu(2+)(aq) + 2OH(-)(aq) » Cu(OH)2
What is the result of an iron(III) with Sodium Hydroxide test?(2)
Orange-brown precipitate is formed in presence of iron(III) ions.
Fe(3+)(aq) + 3OH(-)(aq) » Fe(OH)3
What is the result of an iron(II) with Sodium Hydroxide test?(2)
Dirty green precipitate is formed in presence of iron(II) ions.
Fe(2+)(aq) + 2OH(-)(aq) » Fe(OH)2
How can you test for ammonia in a solid or in solution?
Sodium hydroxide solution reacts with Ammonium to produce Ammonia gas which can be tested for.
NH4(+)(aq) + OH(-)(aq) » NH3(g) + H2O(l)
What is the test for Carbonates and Sulphates?(4)
Add HCl to the sample with the carbonate. Gas is given off. Test the gas using limewater to see if it is CO2.
CO3(2-)(s) + 2H(+)(aq) » CO2(g) + H2O(l)
For sulphates, also add HCl to the sample with the sulphate. Then add Barium Chloride solution. White precipitate will form.
Ba(2+)(aq) + SO4(2-)(aq) » BaSO4
How can we find out whether water is pure or not?
Measure freezing or boiling point. Pure water freezes at exactly 0 celsius and boils at exactly 100 celsius at 1 atmosphere pressure.
How are Chlorides, Bromides and Iodides tested for?(3)
Add enough dilute nitric acid to make it acidic.
Add silver nitrate solution to chloride, bromide or iodide.
A white precipitate shows the presence of chloride ions, cream precipitate shows presence of bromide ions, yellow precipitate shows presence of iodide ions.
