10. Strength of Acids and bases Flashcards
What does concentration refer to in a solution?
The quantity of solute dissolved in a set volume of solvent.
What is a concentrated solution?
A solution that contains a lot of solute.
What is a dilute solution?
A solution that contains a little solute.
Define strength in terms of acids and bases.
How well a solute dissociates in solution.
What characterizes a strong electrolyte?
A majority of the solute has dissociated.
What characterizes a weak electrolyte?
Only a small amount of the solute has dissociated.
What is a non-electrolyte?
A solution with no solute dissolved in it.
List three examples of strong acids.
- Hydrochloric acid
- Nitric acid
- Sulphuric acid
List three examples of weak acids.
- Hydrofluoric acid
- Acetic acid
- Oxalic acid
List three examples of strong bases.
- Sodium hydroxide
- Calcium hydroxide
- Potassium hydroxide
List three examples of weak bases.
- Ammonia
- Aluminium hydroxide
- Methylamine
What occurs when a strong acid like HCl is dissolved in water?
It almost fully dissociates into its ions.
What is the Ka value of a strong acid like HCl?
1.3 x 10^6.
What does a high Ka value indicate about an acid?
The equilibrium position resides to the right ([products] > [reactants]).
How does a weak acid behave in solution?
It does not fully dissociate into ions.
What is the Ka value of acetic acid?
1.8 x 10^-5.
What does a low Ka value indicate about an acid?
The equilibrium position sits to the left ([reactants] > [products]).
Describe the pH of a strong acid.
Very low pH values.
Describe the pH of a strong base.
Very high pH values.
What is the pH range of a weak acid?
Below 7 but closer to 7.
What is the pH range of a weak base?
Above 7 but closer to 7.
Explain how the four species in phosphoric acid dissociation are ranked in terms of acid strength.
Based on their Ka values:
* H3PO4 (Ka = 7.5 x 10^-3)
* H2PO4- (Ka = 6.2 x 10^-8)
* HPO4^2- (Ka = 4.8 x 10^-13)
How can the acidity constant be used to describe a strong acid?
It shows high dissociation into ions.
How can the acidity constant be used to describe a weak acid?
It shows a preference to remain in its molecular form.
