Chapter 4 - Acids and redox Flashcards
What is a Bronsted- Lowry Acids
They are defined to be proton donors.
What is a Bronsted-Lowry Base
They are defined to the proton acceptors
Give 3 examples of strong acids
Sulfuric acid (H2SO4) Hydrochloric acid (HCl) Nitric acid (HNO3) Because they are all inorganic acids (or minerals)
Give an example of a weak acid
Ethanoic acid (CH3COOH) Just carboxylic acids in general because they are organic acids.
What is the difference between an alkali and a base
An alkali is any soluble base.
3 examples of strong alkalis
NaOH
KOH
Ca(OH)2
1 example of a weak acid
NH4OH
acid + alkali –>
salt and water
acid + carbonate –>
salt + water + carbon dioxide
Ionic equation for neutralisation
H+(aq) + OH-(aq) –> H20 (l)
Explain sulfuric acid’s strength
It has 2 hydrogen atoms, but it is only strong for one of them. So it fully dissociates with 1, and then partially dissociates in the other.
H2SO4(aq) –> H+(aq) + HSO4-(aq)
HSO4-(aq) H+(aq) + SO4 2- (aq)
ionic equation for acid and oxides
2H+ + O2- –> H20
ionic equation for acid and carbonates
2H+ + CO3 2- –> H2O + CO2
ionic equation for when water mixes with hydrogen
H+(aq) + H2O(l) –> H3O+(aq)
This happens by a dative covalent bond because the oxygen had 2 lone pairs, one of which it now shares with this third hydrogen.
The new compound is called hydroxonium.
What is titration
A technique used to accurately measure the volume of an unknown solution that reacts exactly with another known solution.
What can titrations be used for
finding the concentration of a solution
identification of unknown chemicals
finding the purity of a substance
Explain diprotic molecule
It is a molecule that has 2 hydrogens. Immediately, this is the stronger acid because it has more hydrogen ions to release and carry the charge.
As a solution is diluted, what happens to its current flow
If a solution is diluted, the concentration of H+ ions decreases. If there is less ions to carry the charge, the electrical conductivity will decrease.
Why does a stronger acid have a higher electrical conductivity?
A stronger acid can ionise fully and release more ions per unit of volume of solution to carry the charge through the electrolyte.
Rule for halogens
They are usually -1.
But they are positive with oxygen and fluorine
Rule for hydrogen with metals
-1 oxidation number
Rule for hydrogen with non- metals
+1 oxidation number
Rule for oxygen
Usually -2
But -1 is peroxide (H2O2)
Rule for fluorine
Always -1
