BITS THAT FALL OUT OF YOUR HEAD Flashcards
How to prepare an Insoluble Salt? (In this Case Lead Sulfate)?
- Add 1 Spatula of Lead Nitrate to a test tube.
- Add Water to dissolve it (Deionised water to make sure there are no other ions about)
- Shake it Thoroughly to ensure all the Lead Nitrate has dissolved
- Do the same with 1 spatula of Magnesium Sulfate in another Test tube
- Tip the two solutions into a small beaker, and give it a good stir to make sure it’s all mixed together. The Lead Sulfate should precipitate
- Put a folded piece of filter paper into a filter funnel and stick the funnel into a conical flask
- Pour the contents of the beaker into the middle of the filter
Make sure the solution doesn’t go above the filter paper-otherwise some of the solid could dribble down
the side
- Swill out the Beaker with more deionised water, and tip this into the filter paper- to make sure you get all the precipitate from the beaker
- Rinse the contents of the filter paper with deionised water to make sure that all the soluble magnesium nitrate has been washed away
- Then just scrape the Lead onto fresh filter paper and leave it to dry in an oven
What are the two ways to make a soluble salt?
React an acid with an excess of a solid metal, metal oxide, hydroxide or carbonate
Titration method
How would you tell when to use which method of making soluble salts?
If it is Na, K or Ammonium Salt
Then use Titration Method
How to make Copper (II) Sulfate Crystals?
-Heat acid in a water bath -speeds up the reaction between the acid and the insoluble base.
Do this in a fume cupboard to avoid releasing acid fumes into the room
-Then add the base to the acid - the base and acid will
react to produce a soluble salt (and water).
You will know when the base is in excess and all the acid has been neutralised because the excess solid will just sink to the bottom of the flask
Filter off the excess solid to get a solution containing only salt and water
Heat the solution gently, using a Bunsen Burner, to slowly evaporate off some of the water.
Leave the solution to cool and allow the salt to crystallise.
Filter off the solid salt and leave it to dry
Which Chlorides are insoluble or soluble?
Lead and Silver are Insoluble
Which Sulfates are Insoluble or Soluble?
Barium and Lead (Insoluble)
Silver and Calcium (Insoluble)
Which Carbonates are Insoluble or soluble ?
Sodium, Potassium and Ammonium ones (Insoluble)
Which Hydroxides are insoluble or soluble?
Sodium, Potassium and Calcium ones (Soluble)
Which Nitrates are Insoluble?
NONE
What does it mean by Saturated?
an organic molecule in which all the covalent bonds between carbon atoms are single bonds
What is an Alloy?
Mixture of a metal with, usually , other metals or carbon
If you start with Potassium Bromide (KBr (aq) colourless) and add Cl2 water what will you observe
Orange Solution (Br2)
If you start with KI (aq) and add Cl2 water, what will you observe?
Brown
If you start with KI and add Br2 water, what will you observe?
Brown
Acid + Metal + Carbonate
Salt + Water + Hydrogen
How do you test for carbonates?
.You need to react Hcl or any acid to the Carbonate
.Then you can test for Co2 (If limewater turns cloudy in the presence of Co2)
As 2Hcl + Co3 –> Co2 + H2O
How do you test for Sulfates?
We test for sulfates using Hydrochloric Acid and Barium Chloride (Barium Chloride is more important).
We should then get Barium Sulfate which forms a white precipitate which tells that sulfate is present.
XSo4 (2-) + BaCl2 –> BaSO4
How do you test for Halide Anions?
You must add (Nitric acid and Silver Nitrate to the Halide anion). The Silver Nitrate (AgNo3) then disperses which allows Silver to react with the Halide anion. If this performs a precipitate colour according to the certain halide anion, it is an anion.
What colour should Agcl turn in a Halide anion test?
White Precipitate
What colour should AgBr turn in a Halide anion test?
Creamy Precipitate