Acid-base reactions Flashcards
What is an Arrhenius’ acid?
A substance that produces hydrogen ions (H+) or hydronium ions (H30+) when it dissolves in water
What is an Arrhenius’ base?
A substance that produces hydroxide ions (OH-) when it dissolves in water.
What is a Lowry-Bronsted acid?
A proton or H+ ion donor
What is a Lowry-Bronsted base?
A proton or H+ ion acceptor
What is an alkali?
A soluble base that contains hydroxide ions (OH-)which can be released into the solution
What is the difference in the ways that acids and bases ‘release’ their ions into water?
Acids ionise their ions in water, while bases dissociate their ions in water
Define ionise
The process whereby COVALENT compounds break up into ionic substances for the first time
(usually in the presence of water in these cases)
Define what it means when a substance dissociates its ions
The process whereby ionic compounds break up into their separate ions in the presence of water
Why is the H+ ion called a proton
It is essentially a Hydrogen atom that has lost its electron. As Hydrogen does no contain any neurons, there is effectively only a proton left in the + ions.
What are conjugate acid-base pairs?
Compounds that differ by the presence of 1 proton or H+ ion.
What do we call substances that can act as either acids or bases?
Amphiprotic or ampholytes
Define a strong acid
An acid which ionises completely in water
to form a high concentration of H3O+ ions
Give 3 examples of strong acids
- Hydrochloric acid (HCl)
- Suphuric acid (H2SO4)
- Nitric acid (HNO3)
Define a weak acid
An acid which ionises incompletely in water
to forma low concentration of H3O+ ions
Give 2 examples of weak acids
- ethanoic acid (CH3COOH)
- oxalic acid (C2 H2 O4)
Define a strong base
A strong base dissociates completely in water to form a high concentration of OH- ions
Give 2 examples of strong bases
- Sodium hydroxide (NaOH)
- Potassium hydroxide (KOH)
Define a weak base
A weak base dissociates or ionises incompletely or partially in water to form a low concentration of OH- ions.
Give 5 examples of weak bases
- ammonia (NH3)
- Potassium carbonate (K2CO3
- Sodium hydrogen carbonate (NaHCO3)
- calcium carbonate (CaCO3)
What are concentrated acids or bases
And how are they different to dilute acids and bases
These acids/bases contain a large amount (#moles) of the acid/base in proportion to the volume of water.
Conversely small amount (#moles) for dilute acids/bases
Define concentration
A ratio of the amount of solute to the volume of solvent in a solution
In terms of conductivity what is the difference between strong and weak acids
Same applies to bases**
Strong acids have:
- a high concentration of ions
- because of their high degree of ionisation
- Thus they will be good conductors of electricity
Lower degree of ionisation means lower concentration which means less conductivity
Describe the reactivity of strong and weak acids and bases
Strong = react faster
Because there will be more ions present int he solution
Strong acids or bases will have higher degrees of ionisation or dissocitation (than weak acids or bases)
Define a dilute acid
Contain small amount (#moles) of acid or base in proportion to volume of water
Define hydrolysis
The reaction of a salt with water
Equivalence point of a titration
Endpoint
The point at which the acid or base has completely reacted with the acid or base
The point where the indicator changes colour
Auto ionization of water
The reaction of water with itself to form h30+
