Section 4-Inorganic Chemistry P1 (pg41-50) Flashcards
(59 cards)
acid + metal ->
salt + hydrogen
How does how a metal reacts with an acid tell you about the metals reactivity?
- the more reactive the metal, the faster the reaction will go
- very reactive metals react explosively
Describe an experiment which shows how metals reacting with acids can tell you information on the metal’s reactivity:
- set up three boiling tubes and fill them with equal volumes of dilute HCl
- place pieces of Mg, Zn, Fe in separate test tubes (keeping the size and shape the same)
- the speed of the reaction is determined by the rate at which bubbles of H are produced
- use the test for H to confirm it is H, the Mg should give off the loudest ‘squeaky pop’
metal + water ->
metal hydroxide + hydrogen
less reactive metal + steam ->
metal oxide + hydrogen
What metals don’t react with acids or water?
Metals from copper down in the reactivity series
below hydrogen in the reactivity series
The reactivity series:
Potassium Sodium Lithium Calcium Magnesium Aluminium CARBON Zinc Iron Lead HYDROGEN Copper Silver Gold
(Potato Soup Lives Cutely Mearly Always Cause Zoos In Leek Happily Complete Soup Group)
What is a displacement reaction/what happens?
In a displacement reaction, a more reactive metal will displace a less reactive metal from a compound.
-they are redox reactions
What happens when a metal carbonate decomposes?
Metal Carbonate –> Metal Oxide + Carbon Dioxide
What happens when a hydrated compound decomposes?
Hydrated Compound –> Anhydrous Compound + Water
When a metal reacts with water is an acid or alkaline formed?
An alkaline solution
If an element displaces a compound is it more or less reactive?
It’s more reactive
What happens if a displacement reaction occurs?
A change in temperature will happen
What do iron and steel corrode to make?
rust - rust is only used to describe the corrosion of iron
When does rusting happen?
when iron is in contact with oxygen and water
What type of reaction occurs when iron rusts?
oxidation reaction
- iron gains oxygen to form iron (III) oxide
- water then loosely bonds to it forming hydrated iron (III) oxide
What is the word equation for rusting?
iron + oxygen + water -> hydrated iron(III) oxide [rust]
What are the two main methods for preventing rusting?
Barrier methods
Sacrificial methods
What are the barrier methods for the prevention of rust?
- painting/coating with plastic - ideal for big or small structures (can be decorative too)
- oiling/greasing - used when moving parts are involved (like bike chains)
What are the sacrificial methods for the prevention of rust?
This involved putting a more reactive metal than iron with the iron
- zinc is often used, it is oxidised instead of the iron
- galvanising or big blocks of zinc blocks can be bolted to the iron (used on ship hulls, underground iron pipes)
What is galvanising?
Galvanising is when a coating of zinc is sprayed onto the object you are protecting by sacrificial methods
What do you remember for redox reactions?
OIL RIG (of elections)
O - oxidation
I - is
L - loss (of elections)
R - reduction
I - is
G - gain (of elections)
Define oxidation:
Oxidation is the gain of oxygen
Oxidation is the loss of electrons
An oxidisation reaction involves an oxidising agent
Define reduction:
Reduction is the loss of oxygen
Reduction is the gain of electrons
An reduction reaction involves a reducing agent
