Unit 1

Question 1

Ionisation energy

Answer 1

Energy required to pull one mole of electrons away from one mole of gaseous atoms

Question 2

Electronegativity

Answer 2

Atom which has a strong attraction for bonding is said to be highly electronegative

Question 3

Collision theory says that a chemical reaction takes place when

Answer 3

Molecules have sufficient energy known as the Ea

Molecules collide with the correct geometry

Question 4

The number of collisions is affected by

Answer 4

Concentration
Particle size
Pressure

Question 5

Activation energy is affected by

Answer 5

Temperature

Question 6

How does increasing the temperature affect the reaction rate

Answer 6

More particles will have the minimum energy and therefore more reactions will take place

Question 7

What is activation energy

Answer 7

Ea

Sufficient energy for a reaction to take place

Question 8

Catalysts increase reaction rate by

Answer 8

Allowing the reaction to take place via an alternative route that has a lower activation energy

Question 9

Two types of catalyst

Answer 9

Heterogeneous- different state from substrate

Homogeneous- same state

Question 10

How to measure relative rate

Answer 10

RR=1/time taken for reaction

Question 11

Enthalpy

Answer 11

Measure of chemical potential energy contained in a substance

Question 12

Change in enthalpy =

Answer 12

Hp-Hr

Question 13

In an exothermic reaction the products have_____ energy than the reactants

Answer 13

Less

Therefore always negative

Question 14

In an endothermic reaction the products have_____ energy than the reactants

Answer 14

More

Therefore always positive

Question 15

Intermolecular bonding

Answer 15

Van der waals and between different molecules eg water and water

Question 16

Intramolecular bonding

Answer 16

Bonding within a molecule eg hydrogen and oxygen in water

Question 17

Non polar

Answer 17

Pure equal forces of attraction

Question 18

Polar

Answer 18

Slightly negative or slightly positive

Question 19

Ionic

Answer 19

Very electronegative atom takes an electron away from the other, forming an ion

Question 20

Properties of ionic

Answer 20

High melting point
Conducts electricity when molten or solution
Always solid room temp

Question 21

What to remember about solubility of substances

Answer 21

Like dissolves in like

Question 22

Covalent molecular properties

Answer 22

Any state at room temp
Lower melting point
Never conducts

Question 23

Covalent network substances

Answer 23

Carbon
Silicon
Boron

Question 24

London dispersion forces

Answer 24

Weak electrostatic attractions due to a temporary dipole forming
Can be found in everything
Only force of attraction for non polar
As number of electrons increase, strength of LDF increases

Question 25

Dipole

Answer 25

Molecules in which an unequal distribution results in one side being slightly charged

Question 26

Permanent dipole-Permanent Dipole

Answer 26

Electrostatic attractions between permanent dipoles in molecules Only for polar Strong

Question 27

What substances have PDPPDP

Answer 27

Aldehydes and ketones

Question 28

Hydrogen bonding

Answer 28

Occurs when hydrogen is bonded next to a highly electronegative element such as oxygen, nitrogen or fluorine Occurs in water very strong