Module 2 Chapter 3 - Amount Of substance

Question 1

What is Avogadros constant

Answer 1

6.02 * 10^23

the number of particles in each mole of carbon-12

Question 2

What is empirical formula

Answer 2

It is the simplest whole number ratio of atoms of each element in a compound

Question 3

When doing the hydrated salts practical what are the two assumptions made?

Answer 3

1. All of the water has been lost

2. No further decomposition

Question 4

Why is it difficult to achieve theoretical yield

Answer 4

1. The reaction may not go to completion
2. Other reactions may have taken place alongside the main reaction
3. Purification of the product may result in loss of some product

Question 5

What is limiting reagent?

Answer 5

The reactant that is completely used up first and stop the reaction

Question 6

What does it mean to have a high atom economy

Answer 6

It produces a large proportion of desired products and few unwanted waste products
It is important for sustainability as they make best use of natural resources

Question 7

How to convert from dm^3 to m^3

Answer 7

divide by 1000

Question 8

How to convert from cm^3 to m^3

Answer 8

divide by 1,000,000

Question 9

How to convert from degrees to kelvin

Answer 9

+273

Question 10

How to convert from tonne to gram

Answer 10

multiply by 1,000,000

Question 11

The student did not obtain the volume of gas predicted .
apart from further repeats, suggest 2 improvements to the practical procedure that would allow the student to obtain a more accurate result

Answer 11

1. Heat until no further gas is produced

2. Wait until the gas has cooled to room temperature before measuring the volume