Acids and Redox Flashcards
What element do all acids contain?
Hydrogen
What happens when an acid is dissolved in water?
Releases H+ ions into the water as protons
Define strong acid
An acid that completely dissociates in solution releasing all H+ ions
Define weak acid
An acid that only partially dissociates in aqueous solution
Define a base
Something that neutralises an acid to form a salt
Give 4 examples of bases
Metal Oxides, Metal Hydroxides, Metal Carbonates and Ammonia
Define an alkali
A base that dissolves in water to release OH- ions into the solution
What happens during a neutralisation reaction?
H+ ions react with base to form a salt and neutral water. The H+ ions from the acid are replaced by metal or ammonium ions from the base.
Acid + Metal Oxide =
salt and water
Acid + Alkali=
salt and water
Write the ionic equation of an acid and an alkali
H+(aq) + OH-(aq) = H20 (l)
Acid + Metal Carbonate =
Salt + Water + Carbon Dioxide
What is a titration?
A technique used to accurately measure the volume of one solution that reacts exactly with another
What 3 things is a titration used for?
Finding the concentration of a solution
Identification of unknown chemicals
Finding the purity of a substance
Where do you measure from in a burette?
The bottom of the meniscus
What difference is accepted in titrations when calculating an average?
0.1 cm^3
What is the oxidation number for an element?
0
What is the oxidation number of ‘O’ in peroxides?
-1
What is the oxidation number of ‘O’ bonded to ‘F’?
+2
What is the oxidation number of ‘H’ in metal hydrides?
-1
What does the sum of the oxidation number equal?
Total Charge
What does reduction mean in terms of electrons?
Reduction is the gain of electrons
What does oxidation mean in terms of electrons?
Oxidation is the loss of electrons