Lec 4

Question 1

Moisture content influences physical properties such as

Answer 1

1)density
2)weight
3)viscosity
4)refractive index
5)electrical conductivity

Question 2

Determine moisture/water content method:

Answer 2

1)drying method
2)halogen moisture analyser
3)karl fischer titration

Question 3

About drying method

Answer 3

-monitor the weight loss from drying till the weight of sample is constant
-oven,weighing balance and desiccator

Cons:
-time consuming
-chances of losing other volatile sample components during process

Question 4

Halogen moisture analyzer

Answer 4

-sample is weighed and heated by infrared radiator
-take place chemical reaction
-more specific

Pros:
-high accuracy and precision
-fast and reliable result
-high sensitivity
-process can be automated
-short analyse time
-small amount of sample is needed

Question 5

2 type of KF titration method

Answer 5

1) volumetric method
(First trace of excess iodine is present)
2) coulometric method
(Trace of unreacted iodine is detected)

Question 6

KF instrument

Answer 6

Titration vessel:
-determine and Indicate the degree of dryness of the equipment
-cannot use the equipment unless it’s dry

Sample introduction:
-drift should be controlled before adding the sample