C2.3 How much?

Question 1

What is a mole?

Answer 1

the relative atomic mass in grams

Question 2

What is the percentage yield?

Answer 2

amount of product produced/maximum amount of product possible x100

Question 3

Why would there not be 100% yield in chemical reactions?

Answer 3

reaction may be reversible, might give unexpected products, product may be left on apparatus, reactants may not be completely pure, products may be mixed and hard to separate

Question 4

ammonium=

Answer 4

ammonia +hydrogen

Question 5

What is chromoatography?

Answer 5

the process whereby small amounts of dissolved substances are separated by running a solvent along a material such as absorbent paper

Question 6

Advantages of modern instruments

Answer 6

more accurate, quicker, analyse small samples

Question 7

Disadvantages of modern instruments

Answer 7

expensive, special training, only comparison data

Question 8

What is gas chromatography?

Answer 8

the process of separating the components in a mixture by passing the vapours through a column and detecing them as they leave the column at different times

Question 9

What is a mass spectrometer?

Answer 9

a machine that can be used to analyse small amounts of a substance to identify it and to find its relative molecular mass