Acid Base Salt Preparation + Chemical Tests Flashcards
Give four examples of the type of compounds that are alkalis
Metal hydroxides, some metal oxides in water, some metal carbonates in water, ammonia in water
Which metal oxides are soluble in water
Potassium, sodium, calcium
Give an example of a metal carbonate that is soluble in water
Sodium carbonate
Copper oxide and sulfuric acid react to give what?
(State the colour change aswell)
Copper sulfate + Water
Black copper oxide becomes blue solution
Metal oxide + acid—-)
Salt + water
Metal hydroxide + acid—-)
Salt + water
Carbonate + acid—-)
Salt + water + carbon dioxide
Explain why water is produced when a metal oxide reacts an acid
Because the O2- ions in the oxide react with the H+ ions in the acid to produce H2O
Explain why water is produced when a metal hydroxide reacts with an acid
Because the OH- ions in the hydroxide react with the H+ ions in the acid to produce H2O
State the product when copper carbonate reacts with sulfuric acid
And state the colours of the reactants and products
Copper sulfate + carbon dioxide + water
Copper carbonate is green, copper sulfate will be blue
(Remeber that when a metal carbonate reacts with an acid it’s a neutralization reaction,
And whenever copper carbonate reacts with any dilute acid a blue salt is formed)
When magnesium reacts with hydrochloric acid,
State the products
And the colour of the product
And state why the color is why it is
Magnesium chloride + hydrogen
Colourless
Because the magnesium dissolves
State what is the difference when aluminum reacts with cold dilute acid and when it reacts with warm dilute acid
When reacting with cold acid, a thin layer of aluminum oxide is formed
When reacting with warm acid, the thin layer is removed and it reacts more vigorously
What is a base
A substance that can neutralize an acid
What is an alkali
A source of OH- ions in a solution
What is the product when ammonia reacts with an acid
An ammonium salt
All sulfates are soluble except
Lead, barium, calcium
Nitrates
(Solubility:)
All nitrates are soluble
Is copper chloride soluble
Yes
(Because all chlorides are soluble except silver and lead)
Is magnesium nitrate soluble
Yes
(Because all nitrates are soluble)
Is lead chloride soluble
No
(Because all chlorides are soluble except silver and lead chloride)
Is lead sulphate soluble
No
(All sulfates are soluble except from lead, barium and calcium)
Carbonates
(Solubility:)
Only potassium sodium and ammonium carbonates are soluble,
The rest are insoluble
Hydroxides
(Solubility:)
Only potassium, sodium and calcium are soluble
(The rest are insoluble)
Is calcium sulfate soluble
No
(Because all sulfates are soluble except lead, barium and calcium)
Is lithium sulfate soluble
Yes
(Because all sulfates are soluble except lead, barium, calcium)
Is magnesium carbonate soluble
No
(Only potassium , sodium and ammonium carbonates are soluble. All other carbonates are insoluble)
Is ammonium carbonate soluble
Yes
(Only sodium, potassium and ammonium carbonates are soluble. The rest are insoluble)
Is magnesium hydroxide soluble
No
(Only potassium, sodium and calcium hydroxide de are soluble. The rest are insoluble)
Is ammonium hydroxide soluble
Yes
(Even though only sodium, potassium and calcium hydroxide are soluble, all compounds of ammonia will always be soluble)
Sulfates
(Solubility:)
All sulfates are soluble, except lead, barium, calcium
Explain why a different method be required to make soluble salts using potassium, sodium or ammonium, compared to other methods
Because sodium potassium and ammonium are soluble in water
So once the reaction has been complete with the acid, the excess solid would just dissolve
So you wouldn’t know when the reaction is complete and how much volume exactly of solid was required to neutralize the reaction
What is the general formula to make a soluble salt
Acid + insoluble base —) soluble salt + water
Why method could you use to make a soluble salt with potassium, sodium or ammonium in it
Use a titration
When making hydrated copper sulfate crystals, why could you not simply evaporate them to dryness
Bc then you would be left with anhydrous salt, a white powder
What colour is anhydrous copper sulfate
White powder
What is water of crystallization
When water is chemically bonded to the salt, so forms part of its crystal structure
What is a risk when evaporating crystals simply with a Bunsen burner
The high temperatures could cause a thermal decomposition reaction to occur, so the crystals may begin to break down
What is the purpose of adding an excess amount of insoluble base, when making a soluble salt
So that you know when the neutralization reaction has been completed, so when all the acid has been neutralized
Give the word equation to make copper sulfate crystals
Copper oxide + sulfuric acid —) hydrated copper sulfate crystals