How is a soluble salt made?
Enjoying Flashcards?
Tell us what you think
How is a soluble salt made?
A soluble salt can be made by the reaction of:
an acid with an insoluble base.
an acid with an alkali.
an acid with a metal.
an acid with an insoluble carbonate.
Why is the insoluble base added in excess during the preparation of a soluble salt?
The insoluble base is added in excess to ensure that all of the acid has reacted.
What step is taken to remove the excess insoluble base after the reaction?
The excess insoluble base is removed by filtration.
What is left in the solution after the excess base is removed?
After removing the excess base, only the salt and water remain in the solution.
Write the balanced symbol equation for the preparation of copper(II) sulfate from copper(II) oxide.
The balanced symbol equation is:
CuO (s) + H2SO4 (aq) ⟶ CuSO4 (s) + H2O (l)
Define the term insoluble base.
An insoluble base is a base that does not dissolve in water.
How are crystals produced from a salt solution?
The solution is heated gently and then left to cool.
Name the method used to prepare a soluble salt from an acid and alkali.
The method used to prepare a soluble salt from an acid and alkali is titration.
Name the piece of equipment which could be used to measure a fixed volume of acid when preparing a soluble salt by titration.
The piece of equipment which could be used to measure a fixed volume of acid is a pipette.
Why is an indicator used during the preparation of a soluble salt by titration?
An indicator will indicate when neutralisation has occured.
True or false?
During the preparation of a soluble salt by titration, the titration is repeated without the indicator.
True.
During the preparation of a soluble salt by titration, the titration is repeated without the indicator.
What is an insoluble salt?
An insoluble salt is a salt that does not dissolve in water or other solvents.
True or False?
Insoluble salts can be prepared using a precipitation reaction. (Extended Tier Only)
True.
Insoluble salts can be prepared using a precipitation reaction.
Define precipitation reaction.
A precipitation reaction is a reaction where an insoluble solid (precipitate) is formed from two soluble reactants
What is meant by a precipitate?
A precipitate is an insoluble solid that is formed from a reaction between two soluble reactants.
What does the method for preparing an insoluble salt involve? (Extended Tier Only)
The method for preparing an insoluble salt involves measuring out a fixed volume of one solution and then adding the second salt solution until it is in a slight excess, to ensure the maximum amount of precipitate will be obtained.
True or False?
The precipitate is recovered by evaporation. (Extended Tier Only)
False.
The precipitate is recovered by filtration and then it must be washed with distilled water to remove reactants that are contaminating the residue (recovered solid).
Give an example of an insoluble salt often made by precipitation. (Extended Tier Only)
Examples of salts made by precipitation include silver and lead(II) salts e.g. lead(II) iodide, silver chloride.
Why is the precipitate washed with distilled water? (Extended Tier Only)
The precipitate is washed with distilled water to remove traces of the solutions it was made from.
State what is meant by an ionic compound.
An ionic compound consists of a giant lattice of positively charged metal ions and negatively charged non-metal ions.
Define the term insoluble.
Insoluble means the substance is unable to dissolve in a solvent, usually water.
True or False?
All ionic compounds are soluble in water.
False.
Not all ionic compounds are soluble in water, some are insoluble.
True or False?
Sodium carbonate is soluble.
True.
Sodium carbonate is soluble.
True or False?
Compounds of potassium are soluble.
True.
Compounds of potassium are soluble.
True or False?
Compounds of sodium are insoluble.
False.
Compounds of sodium are soluble.
Give three examples of insoluble sulfates.
Three examples of insoluble sulfates are:
barium sulfate
calcium sulfate
lead(II) sulfate
True or False?
All nitrates are insoluble.
False.
All nitrates are soluble.
Give an example of a soluble hydroxide.
Examples of soluble hydroxides include:
sodium hydroxide
potassium hydroxide
calcium hydroxide
True or False?
Silver chloride is soluble.
False.
Silver chloride is insoluble.
Define a hydrated substance.
A hydrated substance is one which is chemically combined with water.
Define an anhydrous substance.
An anhydrous substance is a substance containing no water.
Define water of crystallisation. (Extended tier only)
Water of crystallisation refers to the water molecules present in a hydrated substance.
True or false?
The formula of hydrated copper(II) sulfate is CuSO4∙5H2O. (Extended tier only)
True.
The formula of hydrated copper(II) sulfate is CuSO4∙5H2O.
What is the formula of hydrated cobalt(II) chloride? (Extended tier only)
The formula of hydrated cobalt(II) chloride is CoCl2∙6H2O.
What is the formula of anhydrous copper(II) sulfate?
The formula of anhydrous copper(II) sulfate is CuSO4.
State what is observed when hydrated copper sulfate is heated.
When hydrated copper sulfate is heated the colour change is blue to white and colourless liquid (water) collects at the top of the test tube.
State the equation for the reversible reaction when hydrated copper(II) sulfate, CuSO4.5H2O, is heated. (Extended tier only)
The equation for the reversible reaction when copper(II) sulfate is heated is:
CuSO4.5H2O ⇌ CuSO4 + 5H2O
What colour does anhydrous copper(II) sulfate turn in the presence of water?
Anhydrous copper(II) sulfate turns blue in the presence of water.
How many water molecules are present in CoCl2∙6H2O? (Extended tier only)
There are 6 water molecules present in CoCl2∙6H2O.
What is the formula of anhydrous cobalt(II) chloride?
The formula of anhydrous cobalt(II) chloride is CoCl2.