General + Practical knowledge

Question 1

How accurate should calculations be?

Answer 1

As accurate as your least accurate measurement

Question 2

How many grams are in a tonne?

Answer 2

1,000,000

Question 3

What does volatile mean?

Answer 3

Easily evaporated at normal temperatures

Question 4

How do you convert degrees Celsius into kelvin?

Answer 4

Add 273

Question 5

What is a colorimeter?

Answer 5

It measures colour

Question 6

What is mmol?

Answer 6

It is a milimole

It is 1/1000 of a mole

Question 7

What is the formula for percentage uncertainty?

Answer 7

Uncertainty in the value
———————— X 100
Value

Question 8

How do you work out percentage uncertainty?

Answer 8

Add all of the individual uncertainties together

Question 9

Define accuracy

Answer 9

A value that is considered to be close to the true value

Question 10

Define random error

Answer 10

Something that can not be predicted

Question 11

Define systematic error

Answer 11

An error in a piece of equipment

Question 12

Define interval

Answer 12

The quantity between readings

Question 13

Define repeatable

Answer 13

The original scientist using the same method and equipment, then getting the same result

Question 14

Define reproducible

Answer 14

Different people using different equipment to get the same results

Question 15

Define validity

Answer 15

The suitability of the plan that you have put together to answer the question

Question 16

What is a catagoric variable?

Answer 16

A named variable

Question 17

What is a continuous variable?

Answer 17

A variable with a value

Question 18

What is a control variable?

Answer 18

A variable that is kept constant

Question 19

What are dependent variables?

Answer 19

They are the results gained from changing the independent variable

Question 20

What are independent variables?

Answer 20

The variables that you change

Question 21

What are the rules of electrolysis?

Answer 21

DC power supply connected to two rods (electrodes)
Dissolved in an electrolyte, something able to conduct electricity
Cathode: negative current, cations (positive ions) are attracted to it, reduction
Anode: positive current, anions (negative ions) are attracted to it, oxidation

Question 22

How do you determine the products of electrolysis at each electrode?

Answer 22

The most reactive element will be produced

Question 23

What is an alkyl group?

Answer 23

A hydrocarbon with one hydrocarbon missing

Ends in -thyl

Question 24

How do you convert parts per million into a percentage?

Answer 24

1ppm = 0.0001%

Divide by 10,000

Question 25

What is group 1 in an atom?

Answer 25

The energy level furthest from the nucleus

Question 26

Define wet lab

Answer 26

Physical practical work

Question 27

What is litmus paper?

Answer 27

Paper used to indicate acidity / alkalinity
Blue litmus paper: turns red under acidic conditions
Red litmus paper: turns blue under alkaline conditions

Question 28

Why are anti bumping granules used?

Answer 28

They ensure smooth boiling by preventing the formation of large bubbles

Question 29

What is the container for a sample in melting point apparatus?

Answer 29

Capillary tube

Question 30

What is the catalyst for esterification?

Answer 30

Sulfuric acid

Question 31

What is the purpose of sodium carbonate in esterification?

Answer 31

To remove remaining sulfuric and ethanoic acid

Question 32

What is the purpose of a separating funnel?

Answer 32

To seperate immiscible liquids of different densities

The mixtures can be tapped off separately

Question 33

What is the purpose of round bottomed flasks?

Answer 33

To ensure that heat is spread out evenly

Question 34

What is the purpose of pear shaped flasks?

Answer 34

To allow the recovery of more material than round bottom flasks
Mostly used for distillation

Question 35

How do you test for iodide ions in solution?

Answer 35

Add silver nitrate

A yellow precipitate is produced

Question 36

What is the condition of the reagent in nucleophilic substitution reactions?

Answer 36

An excess of nucleophile

Question 37

Why is an electric heater used over a bunsen burner?

Answer 37

Some products are flammable

Question 38

How do you purify a solid?

Answer 38

Dissolve in a small amount of solvent
Filter
Cool to recrystallize
Filter under reduced pressure (Buchner funnel)
Wash and dry