Short recalls I need to know

Question 1

State the meaning of the term periodicity

(1 mark)

Answer 1

Repeating pattern/ trend

Question 2

Name the property that describes its ability to react as both an acid and and a base

(1 mark)

Answer 2

Amphoteric

Question 3

Explain why water is always neutral

(1 mark)

Answer 3

[OH-] = [H+]

Question 4

Explain why ethanoyl chloride is not used in industrial synthesis

(1 mark)

Answer 4

Corrosive/ forms strong acid

Question 5

Explain how carbon dioxide causes global warming

(2 marks)

Answer 5

• C=O bonds in CO2 absorb infrared radiation
• IR radiation emitted by the earth does not escape

Question 6

Explain why 2 liquids can be sperated from an aqueous solution using as seperating funnel

(1 mark)

Answer 6

Liquids are immiscible

Question 7

State the property of SO2 that causes pollution when it enters rivers

(1 mark)

Answer 7

Acidic

Question 8

State why there is a difference between theoretical and experimental values for lattice formation

(1 mark)

Answer 8

Has covalent character

Question 9

State, in terms of the numbers of fundemental particles, one similarity and one difference between atoms of Cr50 and Cr53

(2 marks)

Answer 9

• Same no. of protons/ electrons
• Different no. of neutrons

Question 10

Give 2 reasons why it is necessary to ionise isotopes before they can be analysed in a TOF mass spectrometer

(2 marks)

Answer 10

• So they are accelerated
• Ions create a current when hitting the detector

Question 11

Give the meaning of the term relative atomic mass

(2 marks)

Answer 11

• Weighted average mass of all the isotopes
• In comparison to 1/12th the mass of a C12 atom

Question 12

State the meaning of the term weak acid

(1 mark)

Answer 12

Partially or slightly dissociates