C4 Chemical change Flashcards
What is produced when metals react with oxygen?
A metal oxide
HIGHER TIER What does OIL RIG stand for?
Oxidation Is Loss & Reduction Is Gain (of electrons)
What is oxidation?
When a substance gains oxygen (HIGHER TIER or loses electrons)
What is reduction?
When a substance loses oxygen (HIGHER TIER or gains electrons)
What type of ions do metals form?
Positive ions
What type of ions do non-metals form?
Negative ions
List the reactivity series
potassium, sodium, lithium, calcium, magnesium, aluminium, CARBON, zinc, iron, tin, lead, HYDROGEN copper, silver, gold, platinum
What is produced when a metal reacts with an acid?
A salt and hydrogen gas
What is the test for hydrogen gas?
A lighted splint makes a squeaky pop (when hydrogen is present)
Name a metal that is found ‘natively’ in the ground
Gold / platinum
What is the name for a rock that contains enough metal to make it economically worthwhile to extract it?
An ore
What is formed when a metal carbonate and an acid react?
A salt + water + carbon dioxide
What is formed when a metal reacts with water?
A metal hydroxide
What is formed when magnesium reacts with nitric acid?
magnesium nitrate + hydrogen gas
What is formed when lithium reacts with water
lithium hydroxide
What colour does universal indicator go in a strong acid?
Red
What colour does universal indicator go in a weak acid?
yellow or orange
What colour does universal indicator go in a neutral solution
green
What colour does universal indicator go in a weak alkali?
blue
What colour does universal indicator go in a strong alkali?
purple
Why can carbon be used to extract iron from its ore?
Iron is less reactive than carbon so carbon ‘steals’ the oxygen from the iron oxide
Give a word equation for the extraction of iron from iron oxide by carbon
iron oxide + carbon -> iron + carbon dioxide
What is formed when calcium reacts with sulfuric acid?
calcium sulfate + hydrogen
What is reduced in this reaction: iron oxide + carbon -> iron + carbon dioxide
The iron oxide is reduced (loses oxygen)
What is oxidised in this reaction:
iron oxide + carbon -> iron + carbon dioxide
The carbon is oxidised (gains oxygen)
What is formed when magnesium reacts with hydrochloric acid?
magnesium chloride + hydrogen
What is an acid?
Something that produces H+ (hydrogen) ions
What is the formula for hydrochloric acid?
HCl
What is the formula for sulfuric acid?
H2SO4
What is the formula for nitric acid?
HNO3
What is the state symbol for a solid?
(s) e.g. Mg (s)
What is the state symbol for a gas?
(g) e.g. H2 (g)
What is the state symbol for a liquid?
(l) e.g. H2O (l)
What is the state symbol for a solution?
(aq) e.g. H2SO4 (aq)
What ion do aqueous solutions of alkalis produce?
OH- (hydroxide) ions
What is the pH of a neutral solution?
7
What is the pH of a strong alkali?
Between 11 and 14
What is the pH of a strong acid?
Between 1 and 3
What is the pH of a weak alkali?
Between 8 and 10
What is the pH of a weak acid?
Between 4 and 6
What is the general equation for a neutralisation reaction?
H+ (aq) + OH- (aq) -> H2O (aq)
What is a salt?
A compound formed when the hydrogen in an acid is fully or partially replaced by a metal ion (or ammonium ion)
What are redox reactions?
Reactions where both reduction and oxidation take place
(Q) In the reaction: Zn + Fe (NO3)2 –? Fe + Zn(NO3)2, which species is oxidised and which species in reduced? Why?
Zinc is oxidised and iron ions are reduced.
This is because zinc loses electrons to form Zn 2+. Iron ions gain electrons to form Fe from Fe 2+
