Chapter 8 Chemistry Salt

normally people get confused with this chapter so I m going to provide all information regarding this chapter.. Happy Reading ^^

-All nitrate salts are soluble in water
-All ammonium salts are soluble in water
-All sulphate salts are soluble in water except barium sulphate,lead(II) sulphate,calcium sulphate.
-All chlorides are soluble in water except lead chloride,silver chloride,mercury chloride
-All carbonates are not soluble in water except sodium carbonate,potassium carbonate and ammonium carbonate.
-Salt containing Sodium , potassium and ammonium are all soluble in water.

This is the important things you all have to know...the basic actually.

Next,

For sodium salts,potassium salts and ammonium salts.(PAS)
To obtain it..
We have to use titration method.
taking an Acid + with sodium hydroxide/potassium hydroxide/ammonium Alkali then we will get the same (PAS) salts..
Water will be produced at the end of experiment.
They also will ask..
How u know the reaction has completed?
Using an indicator like universal indicator/methyl orange/phenolphthalein

Pink to colourless for phneolphthalein
Yellow to orange for Methyl orange

The end-point is determined when the colour changes to (write ur answer based on indicator used)

After the neutralisation process is carried out..
Crystallisation is carried out to obtain pure salt..
Generally,when titration method is carried out..
The alkali must be in the conical flask whereas the acid in the burette..
Ever wonder why?
Because alkali cannot pass through the small hole of burette opening..
It's nature..i guess it's too soapy.
So remember put alkali at the bottom !!

The other experiment is recrystallisation process..

Aim:To get a pure form of copper(II) sulphate.

Hypothesis:A purer form of copper sulphate can be obtained by recrystallisation.

Manipulated variable:impure copper(II) sulphate
Responding variable:Purer copper(II) sulphate
Constant variable: Water

Procedure:
1)Impure copper(II) sulphate crystal are dissolved in distilled water.
2)The solution is heated so as to evaporate some of the water in the solution.This is to make the solution more concentrated.
3)The saturated solution is left to cool.This is to enable crystallisation to occur.
4)The purer copper(II) sulphate crystals are seperated by filtering.They are then washed with distilled water.
5)The wet crystals are then dried by pressing them between two pieces of filter paper.

Conclusion:The crystals obtained are clearer and more bluish than the original crystals.These crystals are purer copper(II) sulphate crystals.