Measurement and Experimental Techniques

Question 1

Function of gas syringe?

Answer 1

Used to collect gases of any density

Question 2

Function of burette and it’s accuracy?

Answer 2

It has an accuracy to 0.1cm3
It is used to measure the volume of a solution accurately

Question 3

Function of pipette?

Answer 3

It is used to deliver an accurate fixed volume of a solution

Question 4

Function of measuring cylinder?

Answer 4

Measures an approximate amount of volume of a solution

Question 5

Function of a beaker?

Answer 5

Measures an approximate amount of volume of a solution

Question 6

What is the meniscus?

Answer 6

The surface of the liquid that curves at the side of the measuring instrument. To get an accurate volume reading, it must be read from the lowest level (if it is a positive quadratic curve) or the highest level of the meniscus (if it is a negative quadratic curve)

Question 7

What is displacement?

Answer 7

Used to collect gases which are insoluble or slightly soluble in water
As the gases does not dissolve in water, they would rise to the top of the gas jar.

Question 8

What is upwards delivery?

Answer 8

Used to collect gases which have lighter density as compared to air [Mr of air is around 28.8 (78% N2 +21% O2)]
NH3 & H2 are gases which can be collected using this method

Question 9

What is downwards delivery?

Answer 9

Used to collect gases which have a heavier density as compared to air [Mr of air is around 28.8 (78% N2 +21% O2)]
Some examples of gases collected using this method include Cl2 , HCl and SO2 .

Question 10

What are the drying agents to dry air?

Answer 10

To dry a sample of gas, we can pass it through drying agents like
- Concentrated sulfuric acid (H2SO4)
- Quicklime (calcium oxide)
- Fused calcium chloride (calcium chloride)

Question 11

Function of concentrated sulfuric acid (H2SO4) as a drying agent?

Answer 11

Used to dry acidic gas only (chlorine / hydrogen chloride gas / carbon dioxide / sulfur dioxide)

Question 12

Function of Quicklime (calcium oxide) as a drying agent?

Answer 12

Used to dry alkaline gas only (Ammonia)

Question 13

Function of Fused calcium chloride (calcium chloride) as a drying agent?

Answer 13

Best choice as it can dry most gases since its neutral (except ammonia)