2.1.4.2 Titration

Question 1

What is titration?

Answer 1

Its a technique used to accurately measure the volume of one solution that reacts exactly with another solution

Question 2

What can titration be used for?

Answer 2

> Finding the conc of a solution
Identification of unknown chemical
Finding the purity of a substance

Question 3

How do you carry out a titration?

Answer 3

1. using a pipette, add a measured volume of one solution to a conical flask. Add a suitable indicator.
2. Place the other solution in a burette
3. Add the solution in the burette to the solution in the conical flask until the reaction has just been completed which is called the end point of a titration. Measure the volume the solution added from the burette
4. You now know the volume of one solution that exactly reacts with the volume of the other solution

Question 4

What are the three main indicator used in titration?

Answer 4

> Methyl orange
Bromothymol Blue
Phenolphthalein

Question 5

Methyl orange indicators:

Colour in acid –> Colour in base –> End point colour

Answer 5

Red in acid
yellow in base
orange end point

Question 6

Bromothymol Blue indicators:

Colour in acid –> Colour in base –> End point colour

Answer 6

yellow in acid
blue in base
green end point

Question 7

Phenolphthalein indicators:

Colour in acid –> Colour in base –> End point colour

Answer 7

colourless in acid
pink in base
pale in pink end point

Question 8

How do you calculate an unknown conc - titration

Answer 8

1. Calculate the amount, in mol, of product that was reacted
2. calculate the amount, in mol, of product that was used (checking if its a 1:1 )
3. Then calculate the conc = n X v

Question 9

How do you calculate an unknown molar mass - titration

Answer 9

1. Calculate the amount, in mol, of product that was reacted
2. calculate the amount, in mol, of product that was used (checking if its a 1:1 )
3. scale the factor to find the amount , in mol, of HX
4. M= m/n