C4 Flashcards
What type of reaction is gaining oxygen?
Oxidation reaction
What happens when you react metals with oxygen?
-Form metal oxide
-Oxidisation reaction occurs
What is the displacement reaction?
A more reactive element will push out (displace)a less reactive element from a compound (displacement reaction)
What does oilrig show?
Oxidisation is loss of electrons
Reduction is gain of electrons
What do acids produce in an aqueous solution?
Hydrogen ions (H+)
What are bases?
Chemicals that can neutralise acid producing a salt and a water
What is an alkali?
The base which is soluble in water
What do alkalis produce in aqueous solution?
Hydroxide ions (OH-)
What pH are acids?
0-6
What pH are alkalines?
8-14
What can we use to determine the pH?
-PH probe
-Universal indicator
What is the neutralisation equation?
(H+)+(OH-) -> H20
What do you all acids contain?
Hydrogen
What salt is produced in hydrochloric acid and sulphuric acid?
-Hydrochloric acid produces -chloride
-sulphuric acid produces -sulphate
What happens when we react an acid with a base or alkali?
We make salt and water
What is a salt?
-Salt contains positive ions which come from base or alkali
-Salt also contain a negative iron which come from acid
What happens when An acid reacts with a metal carbonate?
They make salt, water and carbon dioxide
What is another word for splitting acids?
Ionising
What are strong acids and what are some examples?
Strong acids fully ionise in an aqueous solution
Some examples include hydrochloric acid, sulphuric acid, and nitric acid
What are weak acids and what are some examples?
Weak acids partially ionise in an aqueous solution
Carbonic acid Ethanoic acid and citric acid
What is an order of magnitude?
Where a pH has a 10 times greater concentration of hydrogen plus (H+)
What does the concentration of acid tell us?
The concentration of acid in a given volume of solution
Can solid ionic, compounds, conduct, electricity
No ions are locked in place and can’t move
When can an ionic compounds conduct electricity?
When is melted or dissolved in water and the ions are free to move (electrolytes)
What is the positive electrode in electrolysis?
The anode and it lacks electrons
What is the negative electrode in electrolysis?
Cathode and it’s covered with electrons
What occurs at the cathode and anode during electrolysis?
The Anode loses electrons (oxidation) the cathode gains electrons (reduction)
What is a cryolite used for in electrolysis?
Lowers the melting point
Reduces the amount of energy required
Saves money
What is the half equation of reduction in aluminium oxide?
Al(3) + 3e(-) -> Al
What is the half equation of oxidisation in aluminium oxide?
O(2-) -> O + 2e(-)
Why is electrolysis expensive?
Melting, the compounds requires a great amount of energy
a lot of energy is required to produce the electric current
When is hydrogen produced at the cathode?
If the metal is more reactive than hydrogen, hydrogen is produced
What gas do you make at the anode?
Oxygen gas is produced, apart from when the halogen is present, then the halogen is produced
explain why the positive carbon electrode must be continuously replaced
-at high temp, oxygen reacts with electrode
-electrode burns and wears away
-to produce carbon dioxide
