practical questions

Question 1

How does jet space effect the titre

Answer 1

when it fills during the titration, it will make the titre bigger than expected

Question 2

How does a funnel in the burrette effect the titre

Answer 2

Liquid on the funnel could drip into the burrette making the titre volume smaller than expected.

Question 3

Why is distilled water added to the conical flask during a titration and what is the effect on the reaction mixture?

Answer 3

The water washes the sides of the flask so all acid is washed into reaction mixture. This has no effect on the titration as water doesnt react with reagents or change the number of moles of them.

Question 4

Describe how to calibrate a pH meter

Answer 4

Measure pH of known pH of buffer solution

Question 5

Why is dilute H2SO4 used for redox titrations and not HCl?

Answer 5

Cl- ions in HCl would become oxidised by the mangante ions to Cl2 which would make the titre larger as more volumes of MnO4 would be needed.
(use Ecell values to show the reaction is feasible)

Question 6

How can the thermal stability of carbonates be compared experimentally?

Answer 6

with equal moles of the carbonates,

use a gas syringe to measure amount of gas evolved as carbonate is heated in a certain time frame.

Question 7

Describe the properties of an ideal primary standard

Answer 7

A solid with a high molar mass that has a high degree of purity

• soluble in water
• does not absorb water from atmosphere