Module 2

Question 1

Isotopes

Answer 1

• atoms of the same element
• with different neutron numbers
• and different masses

Question 2

Relative Atomic Mass

Answer 2

• the weighted mean mass of atoms of an element
• compared with 1/12th the mass of a C-12 atom

Question 3

Relative Isotopic Mass

Answer 3

Mass compared with 1/12th the mass of a C-12 atom

Question 4

Atomic Number

Answer 4

The number of protons in the nucleus of an atom of an element

Question 5

Mass Number

Answer 5

The (mean) number of protons and neutrons in the nucleus of an atom of an element

Question 6

Name the ion NO3 -

Answer 6

Nitrate

Question 7

Name the ion OH-

Answer 7

Hydroxyl / Hyrdoxide ion

Question 8

Name the ion Ag+

Answer 8

Silver

Question 9

Formula of sulfate ion

Answer 9

SO4 2-

Question 10

Formula of carbonate ion

Answer 10

CO3 2-

Question 11

Formula of ammonium ion

Answer 11

NH4 +

Question 12

Formula of zinc ion

Answer 12

Zn 2+

Question 13

Mole

Answer 13

The unit for amount of substance (Avogadro’s number of an object e.g., molecule)

Question 14

Avogadro’s number

Answer 14

The number of particles per mole
6.022 × 10²³

Question 15

Molar mass

Answer 15

Mass per mole (g/mol)

Question 16

Empirical formula

Answer 16

The simplest whole number ratio of atoms of each element in a compound

Question 17

Anhydrous

Answer 17

A substance without water

Question 18

Molecular formula

Answer 18

The number of atoms of each element in a molecule of a compound

Question 19

Water of crystallisation

Answer 19

The amount of water found in the crystalline structure of a salt - not chemically bonded

Question 20

Ideal Gas Equation

Answer 20

pV = nRT
pressure x volume = amount (mol) x Ideal Gas Constant x temperature (°K)

Question 21

Percentage Yield Equation

Answer 21

Actual yield (g) / Theoretical yield (g)
x 100

Question 22

Atom Economy

Answer 22

Mr of desired products / Total Mr of reactants
x 100

Question 23

Acid

Answer 23

A substance which releases H+ ions in aqueous solution (dissociates/ionises)

Question 24

Alkali

Answer 24

A substance which releases hydroxyl (OH-) ions in aqueous solution

Question 25

Base

Answer 25

Reacts with an acid to form a salt (includes alkalis)

Question 26

Acid + Metal -->

Answer 26

Salt + Hydrogen

Question 27

Acid + Metal Hydroxide -->

Answer 27

Salt + Water

Question 28

Acid + Metal Oxide -->

Answer 28

Salt + Water

Question 29

Acid + Metal Carbonate

Answer 29

Salt + Water + Carbon Dioxide

Question 30

Oxidation

Answer 30

Loss of electrons (increases oxidation number)

Question 31

Reduction

Answer 31

Gain of electrons (decreases oxidation number)

Question 32

Redox reaction

Answer 32

A reaction in which oxidation and reduction both occur

Question 33

Disproportionation

Answer 33

A reaction where the same element is both oxidised and reduced (2 different products)

Question 34

Orbital

Answer 34

A region around the nucleus that can hold up to 2 electrons

Question 35

Shape of s-orbital

Answer 35

Spherical

Question 36

Shape of p-orbital

Answer 36

Dumbbell

Question 37

Ionic Bonding

Answer 37

Strong electrostatic forces of attraction between oppositely charged ions in a giant lattice structure

Question 38

Structure of ionic compounds

Answer 38

Giant ionic lattice Strong electrostatic attraction between oppositely charged ions

Question 39

Properties of ionic compounds

Answer 39

High melting / boiling point Poor conductor when solid Good conductor when in solution

Question 40

Covalent Bonding

Answer 40

Strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms

Question 41

Dative covalent (coordinate) bond

Answer 41

Both electrons in the covalent bond are donated from the same atom

Question 42

Bond Angle / shape / explanation for CO2

Answer 42

Linear: 180° There are two bonding regions, which repel each other equally / as far apart as possible

Question 43

Bond Angle / shape / explanation for H2O

Answer 43

Non-linear: 104.5° It has two bonding pairs and two lone pairs. Lone pairs repel more than bonding pairs

Question 44

Bond Angle / shape / explanation for BF3

Answer 44

Trigonal planar: 120° There are 3 bonding regions, which repeal each other equally / as far apart as possible

Question 45

Bond Angle / shape / explanation for NH3

Answer 45

Trigonal pyramidal: 107° There are 3 bonding pairs and 1 lone pair. The lone pair repels more than the bonding pairs

Question 46

Bond Angle / shape / explanation for CH4

Answer 46

Tetrahedral: 109.5° There are 4 bonding pairs, which repel each other equally / as far apart as possible

Question 47

Bond Angle / shape / explanation for SF6

Answer 47

Octahedral: 90° There are 6 bonding pairs, which repeal each other equally / as far apart as possible

Question 48

Electronegativity

Answer 48

The ability of an atom to attract the electrons in a covalent bond

Question 49

Permanent dipole-dipole (explanation)

Answer 49

Atoms in a molecule have different electronegativity values - this forms a permanent dipole as the electrons are closer to one end than the other PDDs form between the positive end of one molecule and the negative end of another

Question 50

Induced dipole-dipole (explanation)

Answer 50

Random electron movements within a molecule create an instantaneous dipole. This induces a dipole in a neighbouring molecule, and the two dipoles experience a weak electrostatic attraction (IDD)

Question 51

Hydrogen Bonding

Answer 51

Weak attraction between hydrogen in one molecule and the lone pair of an atom of Oxygen, Nitrogen or Fluorine Strongest type of IMF (special PDD)

Question 52

Properties of H2O from hydrogen bonding

Answer 52

Lower density when solid (as molecules held apart in an open lattice) High melting / boiling points (H-bonds are the strongest IMF)