CHEM

Question 1

Take in energy? (what reaction type)

Answer 1

Endothermic

Question 2

Gives out energy (what reaction type)

Answer 2

exothermic

Question 3

Increase in temp in surrounding/environment ((what reaction type)

Answer 3

exothermic

Question 4

Decrease in temp in surrounding/environment (what reaction type)

Answer 4

endothermic

Question 5

Heat is transferred from an object at high temp to a lower temp object until both of them are ……

Answer 5

equal

Question 6

Bond breaking what type of reaction

Answer 6

Endothermic - absorbs energy

Question 7

Bond forming what reaction type

Answer 7

exothermic - releases energy

Question 8

Enthalpy

Answer 8

Change in Temp

Question 9

Enthalpy and change in enthalpy symbol

Answer 9

H
ΔH

Question 10

Bond Enthalpy

Answer 10

This is the energy required to break one mole of a specific bond type

Question 11

If heat is absorbed (endothermic) ΔH is

Answer 11

positive

Question 12

If heat is released (exothermic) ΔH is

Answer 12

negative

Question 13

Entropy

Answer 13

Measurement of a system’s disorder or randomness

Question 14

Entropy is most and least in

Answer 14

Most in gaseous
Least in solids

Question 15

What all is required for a thing to burn

Answer 15

Heat, oxygen and fuel (substance containing carbon)

Question 16

In which energy diagram is the product energy, less than the reactant energy

Answer 16

Exothermic (energy released is calculated by reactant energy - product energy

Question 17

In which energy diagram is the product energy, more than the reactant energy

Answer 17

Endothermic (Energy absorbed is calculated by product energy - reactant energy)

Question 18

Products of any combustion reaction

Answer 18

Water vapour and Carbon dioxide

Question 19

Incomplete combustion

Answer 19

When there is insufficient oxygen in a combustion reaction and instead of carbon dioxide, carbon monoxide is formed

Question 20

Ignition temp

Answer 20

Min temp required for something to catch fire

Question 21

Bonding

Answer 21

The force of attraction between atoms so that they can be joined chemically

Question 22

Why is bonding done

Answer 22

For an atom to become stable and make the outermost shell full

Question 23

octet rule

Answer 23

the eight-electron arrangement in the outer electron shell of a noble-gas atom

Question 24

Ions

Answer 24

Particles which carry a +ve or -ve charge

Question 25

In bonding, what is used?

Answer 25

valence electrons

Question 26

Metals valency

Answer 26

metals only have 1,2 or 3 valence electrons which they lose, making them cations

Question 27

Types of bonding

Answer 27

Metallic, Ionic, Covalent

Question 28

Metallic bonding

Answer 28

Between two metals or alloys

Question 29

Alloys

Answer 29

A mixture of 2 or more metals

Question 30

Ionic or Electrovalent bonding

Answer 30

Between two ions which are always one metal and one non-metal

Question 31

Covalent Bonding

Answer 31

Between non-metals and non-metals where electrons are shared

Question 32

Properties of metals

Answer 32

Malleability Durability Good heat conductors Good conductors of electricity Sonorous Shiny/Lustrous Very high boiling and melting point

Question 33

Sonorous

Answer 33

When metals strike a hard surface, they produce a sound

Question 34

What is the sea of electrons in metals?

Answer 34

Outer electrons in metals separate from their atoms and become free and delocalised and form a sea of electrons. The atoms which lose these electrons become cations and the other free electrons allow for the movement of heat and electricity, making metals good conductors of both

Question 35

What happens when a metal is hit

Answer 35

Layers of strong and dense lattice slide over each other but do not break unlike ionic compound lattices

Question 36

Why is their sharing of electrons in covalent bonding

Answer 36

No atom wants to give their electrons, so they share to complete their octet

Question 37

Electronegativity

Answer 37

Ability of atoms to gain electrons

Question 38

Max amount of bonds carbon can form with itself

Answer 38

4

Question 39

Catenation

Answer 39

Catenation is the process of atoms of the same element linking together which is also called a chain

Question 40

Why are the oxides of carbon and silicon different even though they are in the same group?

Answer 40

The carbon atom is smaller than the silicon atom

Question 41

Which atom is found in millions of compounds

Answer 41

Carbon

Question 42

Lattice

Answer 42

a 3D arrangement of atoms, ions, or molecules in a crystalline solid.

Question 43

Name a gaseous fossil fuel

Answer 43

Natural Gas

Question 44

Name fuels obtained by distillation of petroleum

Answer 44

Gasoline, Kerosine, Diesel, propane

Question 45

Name two products obtained from petroleum which are not used as fuels

Answer 45

Bitumen and Lubricating Oil

Question 46

A mixture of liquid separate on an industrial scale other than petroleum

Answer 46

Ethanol and water

Question 47

If the oxidation number is positive, then electrons are

Answer 47

lost

Question 48

Which of these condust electricity during liquid state Metallic compounds Ionic compounds Covalent compounds

Answer 48

Ionic compounds

Question 49

Which of these condust electricity during solid state Metallic compounds Ionic compounds Covalent compounds

Answer 49

Metallic compounds

Question 50

Physical properties of Ionic compounds

Answer 50

High melting and boiling point Solid at room temp Poor conductors in the solid state, but good conductors in liquid state

Question 51

Physical properties of Covalent compounds

Answer 51

The state depends on compounds used Boiling and melting points vary depending on the strength of covalent bonds and molecular weight Poor conductors of electricity Good conductors of heat - depending on the compound

Question 52

electrical neutrality

Answer 52

Electrical neutrality is when something has no net electrical charge.

Question 53

Allotropes

Answer 53

Matter, even if of the same element can exist in different physical states

Question 54

Allotropes of carbon and their structure

Answer 54

Graphite - Hexagonal structure with each atom connected with 4 others Diamond - Tetrahedron shape with each atom connected with 4 others

Question 55

Silicia Alltrope shape

Answer 55

Each silicon atom is covalently bonded to four other oxygen atom in a tetrahedral arrangement.

Question 56

Why are metals good conductors of heat and electricity

Answer 56

loosely bound electrons roam freely throughout the metal. This is also known as the sea of electrons which carries heat energy and electricity across the metal and allows it to spread all over

Question 57

Which of the following is maleable and ductile: Ionic bonds, Colvalent bonds or Metallic bonds

Answer 57

Metallic

Question 58

What makes a good fuel

Answer 58

Energy generated Avaliability How can it be stored Cost Toxicity How easy is it to use

Question 59

Why do gases and liquids stay at the bottom of a fractional distillation tank?

Answer 59

Because they have a high boiling point and are much more dense

Question 60

Covalent network

Answer 60

a chemical compound where atoms are bonded by covalent bonds in a continuous network

Question 61

All allotropes are bonded with

Answer 61

covalent bonding