Amount of Substance

Question 1

Define: empirical formula

Answer 1

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

Question 2

Define: molecular formula

Answer 2

the actual ratio of atoms of each element present in a compound

Question 3

Explain the difference between an anhydrous salt and a hydrated salt. (1)

Answer 3

An anhydrous salt contains no water of crystallisation

Question 4

State the advantages of developing a chemical process which has a high atom economy. (4)

Answer 4

• less waste produced
• reaction = more sustainable
• increased profit
• resources will last longer

Question 5

Define: orbital

Answer 5

a region within an atom that can hold up to two electrons with opposite spins

Question 6

Suggest why some countries do not add KI to table salt

Answer 6

Some think its wrong to put additives into the national diet

Question 7

What is meant by the term: hydrated calcium chloride

Answer 7

contains water of crystallisation

Question 8

What is meant by the term: hydrated calcium chloride

Answer 8

Contains water of crystallisation

Question 9

Suggest the formula of the ion responsible for bleaching

Answer 9

ClO-

Question 10

room temperature

Answer 10

25 oC (298K)

Question 11

room pressure

Answer 11

101325Pa

Question 12

converting celcius into kelvin

Answer 12

celcius temp + 273.15