Amount of Substance

Question 1

Diatomic molecules

Answer 1

H2 , N2 , O2 , F2 , Cl2 , Br2 , I2

Question 2

phosphorus exists as …

Answer 2

P4

Question 3

Sulfur exists as …

Answer 3

S8

Question 4

Ammonia formula

Answer 4

NH3

Question 5

Hydrogen peroxide formula

Answer 5

H2O2

Question 6

sulfate ion formula

Answer 6

SO4 2-

Question 7

nitrate ion formula

Answer 7

NO3 -

Question 8

carbonate ion formula

Answer 8

CO3 2-

Question 9

hydroxide ion formula

Answer 9

OH -

Question 10

ammonium ion formula

Answer 10

NH4 -

Question 11

hydrogen carbonate ion formula

Answer 11

HCO3 -

Question 12

Empirical Formula

Answer 12

Simplest whole number ratio of the atoms of each element in a compound.
Used for ionic compounds and macromolecules.

Question 13

Molecular Formula

Answer 13

Shows actual number of atoms of each element in one molecule of the substance.
Used for all molecular covalent substances.

Question 14

Avogadro Constant

Answer 14

number of atoms in 12 g of carbon-12

6.02 x 10-23

Question 15

ideal gas equation

Answer 15

pV = nRT
R = 8.314
Pressure = Pa
Volume =  m3
Temperature = K

Question 16

density equation

Answer 16

Mass = density x volume
Density = gcm-3

Question 17

concentration equation

Answer 17

Moles = volume x concentration
Volume = dm3
Concentration = moldm-3 or M

Question 18

Phenolphthalein indicator

Answer 18

Acidic solution = colourless
Neutral solution = colourless
Alkaline solution = pink
Titrations suitable for
Strong acid - strong base
Weak acid - strong base

Question 19

Methyl orange indicator

Answer 19

Acidic solution = red
Neutral solution = orange
Alkaline solution = yellow
Titrations suitable for
Strong acid - strong base
Strong acid - weak base

Question 20

Strong acids

Answer 20

Hydrochloric acid (HCl)
Nitric acid (HNO3)

Question 21

Weak acids

Answer 21

Ethanoic acid (CH3COOH)

Question 22

Strong bases

Answer 22

Sodium hydroxide (NaOH)
Potassium hydroxide (KOH)

Question 23

Weak bases

Answer 23

Ammonia (NH3)

Question 24

Percentage yield

Answer 24

A comparison of the real and theoretical yield of a reaction.

Question 25

Theoretical yield

Answer 25

maximum mass of product that could be produced.

Calculated from balanced equation.

Question 26

Atom economy

Answer 26

Mr of desired product divided by Mr of all reactants

Question 27

Hydration

Answer 27

Reaction carried out in water

May produce product with water in which is difficult to remove

Question 28

Factors affecting yield

Answer 28

Chemicals may remain stuck to glassware and be wasted
Difficult to extract/separate product from reaction mixture
Unexpected side reactions may occur so intended product may not be created.
Incomplete reaction due to slow reaction time or reversible reaction