Acid And Base

Question 0

What is meant by a Brønsted-Lowry base?

Answer 0

Proton acceptor

Question 1

What is the difference between a strong acid and a weak acid?

Answer 1

Strong acid- dissociates completely

Weak acid- dissociates partially

Question 2

What is meant by Brønsted-Lowry acid?

Answer 2

Proton donor

Question 3

What is meant by the strength of an acid?

Answer 3

The proportion of dissociation

Question 4

When carrying out titration using acid-base indicator, what important factor does the student need to consider when deciding on the most suitable indicator to use for this titration?

Answer 4

The vertical section of the titration curve matches the pH range of the indicator/ colour change of the indicator/ end point.

Question 5

Often measurements of Kw have been taken at different temperatures, especially in experimental work carried out at body temp. What is the consequence of this for published scientific work?

Answer 5

Work is inaccurate or invalid, because Kw varies with Temp.

Question 6

What is the definition of standard enthalpy change of neutralisation?

Answer 6

Energy change accompanying the neutralisation of an aqueous acid by an aqueous base to form 1 mole of water under standard conditions.

Question 7

What are the steps in a experiment that a student can carry out to measure the enthalpy change of neutralisation?

Answer 7

1. Acid and Alkali mixed. ( state amount of acid and alkali e.g 2 moles of acid and 2 moles of alkali)
2. Temp taken at start and finish (calculate temp change)
3. Q= mcAT
   m—> mass/ vol of solution
   c—> specific heat capacity of solution (water is 4.18)
   T—> Temperature change
4. Energy scaled up to form 1 mole of water.
   Q/moles
5. Put sign in front.
   If temp increases -ve
   If temp decreases +ve