3.4 Further Analysis and quantitative chemistry Flashcards
In the flame test, calcium has what colour?
Yellow-red
What is the colour from the flame test of copper?
Green-blue
Wha metal gives a lilac flame?
Potassium
In the flame test, what is the colour given by sodium?
Orange
Do you test for halides
Add a dilute nitric acid then silver nitrate
Why do you have to add nitric acid to a halide solution when analysing it
Because all other acids will react with the silver nitrate making a white precipitate
Name three halides and what colour precipitates are formed
Chloride Cl- : a white precipitate
Bromide Br- : a cream precipitate
Iodine I- : a yellow precipitate
What two substances do you add to a solution to see if it contains sulphate ions
Dilute hydrochloric acid thence barium chloride
What will be formed if sulphate ions are present and you have added hydrochloric acid and barium chloride
A white precipitate will form
The colour brick red is given from what metal flame test?
Lithium
In the flame test, what metal has a pale green flame?
Barium
Why do we use a white tile in titrations?
To help see a colour change
When do we stop repeating measurements for titrations?
When concordant results are achieved.
How do you convert a number from cm^3 to dm^3?
Divide the number by 1000
What indicator is often used in titrations?
Phenolphthalein
