Practicle 4 Testing For Halide Ions Carbonate And Sulphates Flashcards
Why is it important to test for carbonates and sulphates when testing for halides when using silver?
They could be a false reading as silver forms participate with carbonate and sulphate ions
When do you test for carbonates and sulphates when testing for halides?
The beginning
How do you test for a carbonate ion?
Add dilute nitric acid to the sample, if it starts bubbling/ forming gas carbonate ion is detected
What is the gas produced when testing for a positive carbonate?
CO2
What do you need to do in order to have no carbonate ions present?
Add more nitrate acid until gas is not produced
How do you test for sulphates?
What is the positive test? What is this is this a percipitate called?
Add barium nitrate to solution
White percipient formed which is barium sulphate
How to get rid of sulphate ions in solution?
Add excess barium nitrate until all sulphate ions has formed a precipitate
How to get rid of barium sulphate precipitate in solution?
Filter off the solid barium sulphate
What is a reducing agent?
An ion on that donates an electron
Going down the group of period seven halides does it increase in reducing agents?
Why? Nucleus therefore
Yes, it does
It is easier to lose an electron as it is further away from the nucleus/ less attraction
What are the two types of reactions with halide and H2 SO4 whether that being a reducing agent or not? A,R
Acid base reaction
Redox reaction
When does the redox reaction happen within which halides?
Halides that are reducing agents
Write down the acid base, formula equation for sodium chloride and H2SO4?
NaCl(s) + H2SO4(l)->NaH2SO4(s) + HCl(g)
Write down, the redox reaction between sodium bromine and H2SO4?
2H+ + 2Br- + H2SO4 + -> SO2 +2H2O +2Br
What is special about I- ?
What can I do to the sulphur in H2SO4
It is a powerful reducing agent. Therefore it can reduce the sulphur to 3 different products.
What is the three products that I- can you make?
Which one smells like rotten eggs?
SO2, H2S, S8
H2S
When the halides produce a redox reaction, what is added to the reactants and products, side in formula equation?
Reactants: H+
Products: H2O, halide2, SO2
