Chemical Changes
How do most metals get extracted from the ground?
From their ores
What is OILRIG?
Oxidation is Loss, Reduction is Gain - of electrons
Give an example of a real-life endothermic reaction.
Instant cold packs for sports injuries.
What is the activation energy of a reaction?
The minimum amount of energy that particles must have in order to start the reaction.
What is a neutralisation reaction?
The reaction between an acid and an alkali.
What is a displacement reaction?
A reaction where a more reactive metal pushes out a less reactive one from its compound.
What is formed at the negative electrode in a molten lithium oxide solution?
Lithium metal
In an exothermic reaction, which have the lower energy, products or reactants?
Products
Why does increasing temperature increase the rate of a reaction?
Because kinetic energy of particles increases.
Which non-metals are there in the reactivity series?
Carbon and Hydrogen
What salt will be formed in the reaction between sulfuric acid and cobalt oxide?
Cobalt Sulfate
Electrodes are made out of graphite. What is the reason for this?
Because it is a good electrical conductor.
Why is bond breaking an endothermic process?
Because energy is taken in from the surroundings to break the bonds
How do catalysts increase the rate of a reaction?
They provide an alternate pathway with a lower activation energy
What is a strong acid?
Acid that fully dissociates in water.
Which metal is the least reactive in the reactivity series?
Platinum
Complete the following half-equation:
H+(aq) --> H2(g)
2H+(aq) + 2e- --> H2(g)
What is the units for bond energy?
kjmol-1
Why does increasing pressure increase the rate of reaction?
Because there are the same number of particles, but in a smaller space.
What acid is found in vinegar?
Ethanoic acid
What products are formed in the reaction between an acid and a metal carbonate?
Salt, Water, Carbon Dioxide
In an aqueous solution, at the positive electrode there can only be _______ or _______ given off.
Oxygen or a halogen.
N2 + 3H2 --> 2NH3
Calculate overall energy change and state if it is endothermic or exothermic.
H-H = 436
N-H = 391
N=N = 945
-93 kjmol-1
Exothermic
Why does increasing concentration increase the rate of reaction?
Because there are more particles in the same space.
What is a weak acid?
An acid that partially ionises in water.