Corrections

Question 1

Ionisation energy across periods?

Answer 1

Increases

Question 2

Impurities in reactant?

Answer 2

causes less product as some of a has already reacted (eg formed oxide) or there is less of a present to react

Question 3

Group 2 trends downwards

Answer 3

• 1st IE decreases
• AR increases
• melting points decreases
• reactivity increases

Question 4

FeS2 dot cross

Answer 4

• fe 2+ ion, full outer shell
• s2 covalent molecule with 2 extra electrons ▪️so -2 charge

Question 5

AlH4- ion

Answer 5

• 3 bond pairs
• dative covalent bond

Question 6

NaCl use

Answer 6

Bleach /disinfectant

Question 7

Sodium chlorate (v) formula

Answer 7

NaClO3

Question 8

Conjugate base

Answer 8

a chemical compound formed when an acid donates a proton to a base— a base with a hydrogen ion added to it

Question 9

Gram to tonne

Answer 9

Divide by 1000000 to convert g to tonne

Question 10

End point of titration

Answer 10

The endpoint in a titration is the point at which the indicator changes colour, indicating that the reaction has reached completion.

Question 11

Indicator

Answer 11

An indicator is a substance that changes its color in response to a change in pH or other conditions in a solu-tion, and it is used to signal the endpoint of a titration or to monitor the progress of a chemical reaction.

Question 12

Why does hexane have higher bp than propane

Answer 12

3Hexane is a larger molecule than propane and so has more electrons.
4. - This means it experiences stronger van der Waals forces between molecules.
5. - These forces require more energy to overcome, giving hexane a higher boiling point

Question 13

Solubility of hydroxides down group 2

Answer 13

Increases

Question 14

how many electrons in a 2p orbital?

Answer 14

2 electrons in ALL orbitals

Question 15

electrons in 4th shell

Answer 15

32

Question 16

phosphorus formula

Answer 16

p4

Question 17

ions in H4N2O2

Answer 17

• NH4+
• NO3-
• (Give known Polyatomic ions that add to make compound)

Question 18

reaction of alkali metals and chlorides

Answer 18

alkali metal oxides are white solids and the chlorides are colourless crystals - white solid or colourless crystals in reaction

Question 19

Not all AgNO3 has reacted if …

Answer 19

Not all AgNO3 has reacted if a white precipitate forms as Ag+ ions are still present, won’t react as solid/liquid.

Question 20

Metal hydroxide + chlorine

Answer 20

Metal chlorate + salt + water

Question 21

Chlorinated hydrocarbons are ?

Answer 21

Carcinogens

Question 22

4 bonds pairs

Answer 22

109.5, tetrahedral

Question 23

H20 structure

Answer 23

Simple molecular

Question 24

Sf6 shape

Answer 24

Octahedral

Question 25

Asymmetrical

Answer 25

Dipoles cancel

Question 26

Water properties

Answer 26

Liquid denser than solid - as solid h2o molecules are held apart by H bonds Relatively strong h bonds so relatively high bp

Question 27

Name of reaction between agno3 and Cl

Answer 27

Precipitation

Question 28

How many orbitals are occupied in A. Silicon atom?

Answer 28

1s2 2s2 2p6 3s2 3p2 So 8. 6 paired, 2 singly.