Further Analysis and Quantitive Chemistry Flashcards
In the flame test, what colour is lithium?
Crimson
How is a flame test carried out?
Piece of nichrome wire is dipped in hydrochloric acid (to clean it)
Then dipped in compound
Then put in bunson flame
In the flame test, what colour is sodium?
Yellow
In the flame test, what colour is potassium?
Lilac
In the flame test, what colour is calcium?
Brick red
In the flame test, what colour is barium?
Green
Why is it hard to identify compounds using the flame test?
Because the colours mix together
How do you test for carbon dioxide?
The limewater test
How do you test for metal ions using sodium hydroxide solution?
Measure 20mm of solution into test tube
Add sodium hydroxide drop by drop
Swirl after each drop and look for precipitate
When testing for metal ions with sodium hydroxide, what colour precipitate does iron(lll) form?
Brown
When testing for metal ions with sodium hydroxide, what colour precipitate does iron(ll) produce?
Green
When testing for metal ions with sodium hydroxide, what colour precipitate does copper produce?
Blue
When testing for metal ions with sodium hydroxide, a white precipitate is formed. It doesn’t dissolve after adding excess sodium hydroxide. What is it?
Calcium or magnesium
When testing for metal ions with sodium hydroxide, a white precipitate is formed. It dissolves after adding excess sodium hydroxide. What is it?
Aluminium ion
How do you test for sulphate ions?
Add barium chloride solution and dilute hydrochloric acid
If sulphate is present, white precipitate will be formed
How do you test for halide ions?
Add silver nitrate solution and dilute nitric acid
When testing for halide ions, a white precipitate is formed. What ion is present?
Chloride
When testing for halide ions, a cream precipitate is formed. What ion is present?
Bromide
When testing for halide ions, a yellow precipitate is formed. What ion is present?
Iodide
What is a titration used for?
How much of an acid is needed to neutralise alkali. If the concentration of acid is known, the concentration of the alkali can be worked out
How is a titration carried out?
Pipettes is used to measure known volume of alkali into conical flask
Indicator is added (phenolphthalein)
Acid is then placed into burrette
Acid is carefully added to alkali until indicator has changed colour showing neutralisation
Read the volume of acid remaining in burrette
Repeat
What indicator is normally used for a titration?
Phenolphthalein
