Paper 1 topics

Question 1

what is oxidation?

Answer 1

when a substance gains oxygen

Question 2

what is reduction?

Answer 2

when a substance loses oxygen

Question 3

what is crystallisation?

Answer 3

when solid crystals are formed from a solution

Question 4

what is filtration?

Answer 4

when solids are separated from a solution using filter paper

Question 5

what is simple distillation?

Answer 5

when mixtures that have different boiling points are separated

Question 6

what is fractional distillation?

Answer 6

when mixable liquids are separated

Question 7

what is chromotography?

Answer 7

when components of a mixture are separated

Question 8

who discovered electrons?

Answer 8

thomson

Question 9

who carried out the alpha particle experiment?

Answer 9

geiger and marsden

Question 10

who discovered the nucleus?

Answer 10

rutherford

Question 11

who discovered that electrons travel in orbits around the nucleus?

Answer 11

bohr

Question 12

who discovered neutrons in the nucleus?

Answer 12

james chadwick

Question 13

what is the relative mass of a proton?

Answer 13

1

Question 14

what is the relative mass of a neutron?

Answer 14

1

Question 15

what is the relative mass of an electron?

Answer 15

very small

Question 16

what is the relative charge of a proton?

Answer 16

+1

Question 17

what is the relative charge of a neutron?

Answer 17

0

Question 18

what is the relative charge of an electron?

Answer 18

-1

Question 19

what is an isotope?

Answer 19

an element with the same number of protons but different number of neutrons

Question 20

what is ionic bonding?

Answer 20

when electrons are TRANSFERRED from a metal to a non-metal
metals always lose electrons

Question 21

what is covalent bonding?

Answer 21

when electrons are SHARED between non-metals

Question 22

what is metallic bonding?

Answer 22

when electrons in the outer shell become delocalised

Question 23

what is an exothermic reaction? (with examples)

Answer 23

when energy is TRANSFERRED TO THE SURROUNDINGS, which increases its temperature

examples: combustion, oxidation reactions, neutralisations

Question 24

what is an endothermic reaction? (with examples)

Answer 24

when energy is TAKEN IN FROM THE SURROUNDINGS, which decreases the temperature of the surroundings

examples: thermal decomposition, reaction of citric acid

Question 25

what is activation energy?

Answer 25

the minimum amount of energy needed for particles to react

Question 26

what happens with the energy during an exothermic reaction? (and the bonds)

Answer 26

energy is released to MAKE bonds

Question 27

what is the equation to find the enthalpy change? (in terms of bond energies)

Answer 27

energy of reaction = sum of broken bonds - sum of made bonds

Question 28

what is a cell?

Answer 28

2 electrodes dipped in an electrolyte system

Question 29

what is a battery?

Answer 29

2 or more cells connected in series

Question 30

what determines the voltage from the cell?

Answer 30

the identities of metals used as electrodes and the identity and concentration of an electrolyte

Question 31

what are some advantages and disadvantages of hydrogen fuel cells?

Answer 31

ADVANTAGES: no pollutants, no recharging DISADVANTAGES: flammable, toxic chemicals

Question 32

what are properties of ionic substances?

Answer 32

- high melting and boiling points => strong electrostatic forces between oppositely charged ions - don't conduct electricity when solid => ions in fixed positions - only conduct when molten or dissolved in water => ions are free to move

Question 33

what are properties of simple molecular covalent substances?

Answer 33

- do NOT conduct electricity => no ions - low melting and boiling points => weak intermolecular forces

Question 34

what are polymers?

Answer 34

large molecules (VERY large) with atoms linked by covalent bonds

Question 35

what are giant covalent substances? (and examples)

Answer 35

- atoms covalently bonded together in a giant lattice - high melting and boiling points => strong covalent bonds - mostly don't conduct electricity => no delocalised electrons examples: diamond, graphite, silicon dioxide

Question 36

what are alloys?

Answer 36

metals mixed with other elements

Question 37

what is the molar volume of a gas at room temperature and pressure?

Answer 37

24dm³

Question 38

why is it not always possible to have the theoretical amount of product in a chemical reaction?

Answer 38

- reaction may not go to completion because it is reversible - some of the product may be lost when it is separated from the reaction mixture - some of the reactants may react in ways different to the expected reaction

Question 39

what is the law of conservation of mass?

Answer 39

no atoms are made or lost during a reaction, so the mass of products is the same as the mass of reactants

Question 40

what is avagadro's constant?

Answer 40

the number of atoms, molecules or ions in a mole of a given substance. 6.02 x 10²³

Question 41

what is meant by the limiting reactant?

Answer 41

the reactant that is COMPLETELY used up

Question 42

number of moles =

Answer 42

mass / rfm

Question 43

percentage yield =

Answer 43

(actual mass produced / theoretical mass of product) x 100

Question 44

percentage atom economy =

Answer 44

(rfm of desired products / sum of rfm of reactants) x 100

Question 45

concentration (g/dm³) =

Answer 45

mass of solute (g) / volume of solution (dm³)

Question 46

concentration (mol/dm³) =

Answer 46

(concentration x solution volume (cm³)) / 1000

Question 47

volume of gases =

Answer 47

moles of gas x 24

Question 48

percentage by mass =

Answer 48

rfm of chemical / rfm of compound