wrong questions

Question 1

explain why halide ions are present in the mixture containing a halogenoalkane which only has covalent bonds

Answer 1

-halogenoalkanes hydrolyzed by water
-c-halogen bond breaks

Question 2

define term structural isomerism

Answer 2

-same molecular formula
-but different structural arrangement

Question 3

Give three reasons why the product may be removed before its maximum concentration is
achieved.

Answer 3

-eqm pos shift to the right
-remove prod to avoid formation of reactants
-time to reach eqm too long
-unreacted reactants recycled

Question 4

nickel catalyst is used in the first stage Explain why the catalyst is more effective when coated onto an unreactive
honeycomb. (2)

Answer 4

inc suface area
more successful collisions

Question 5

The pool manager maintains the water at a pH slightly greater than 7.0
Explain how this affects the equilibrium established when chlorine is added to water. (2)

Answer 5

Hydroxide / alkali ions react with the acids
Equilibrium moves to the right

Question 6

Explain why chlorine is used to kill bacteria in swimming pools, even though chlorine is toxic

Answer 6

Only used in small amounts
The health benefits outweigh the risks

Question 7

Describe in outline a method to show that the manganese(IV) oxide is not used up
in the decomposition of hydrogen peroxide and that it still functions as a catalyst. (heterogeneous catalyst) 4

Answer 7

filter solid from solution after experiment
dry
reweigh solid
repeat after experiment to see if identical results

Question 8

The third reaction in the airbag is between the metal oxides and silicon dioxide.
State the type of reaction taking place and justify why this reaction is necessary. 3

Answer 8

neutralisation
sodium is corrosive
salt is inert

Question 9

Give a reason why the measurement of the initial rate of reaction is likely to be
less accurate than the measurement of the maximum rate.

Answer 9

hard to draw an accurate tangent

Question 10

react why Naco3 added to organic layer and why it is important to open tap after adding this solution

Answer 10

react w excess hcl
release co2

Question 11

greenhouse gases can absorb infrared radiation. co2 absorbs and o2 does not 2

Answer 11

co2 has polar bonds o2 does not have polar bonds
polarity of co2 changes/dipole moment shifts

Question 12

one disadvantage of cl higher than 3 and lower than 1
cl2 + h2o - hcl + hclo 4

Answer 12

lower-
hclo lower
ineffective bleach

higher-
hcl higher
skin irritation eye irritation

Question 13

shows the steps reaction of barium carbonate in limewater test

Answer 13

-baco3 + 2hcl - bacl2 + co2 + h20
-ca(oh)2 + co2 - caco3 + h20

Question 14

student suggests diff in rate of reaction of strontium and barium with water due to diff of sum of first and second ie discuss suggesting 6

Answer 14

-sum of first 2 ie for barium is lower
-ba bigger atom
- ba more shielding
-outwiegh other factors
-ba greater nuclear charge
-ba reacts faster

Question 15

explain in terms of redox reaction occurring why said halides form different products with concentrated sulfuric acid

Answer 15

-iodide ions better reducing agents
-because iodide ions lose e more readily

Question 16

the melting temp of nas2 is higher than nacl2 even though both is ionic bonding explain diff in melting temp 2

Answer 16

attractive forces between sodium ion and anion is greater with sulfide
- sulfide ion has a higher charge than the chloride ion

Question 17

describe key feature of bonding of carbon atom in graphite that results in it being an electrical conductor 2

Answer 17

one e free to move
each carbon bonded to 3 others

Question 18

suggest why the addition of anhydrous calcium chloride to water results in an increase in temp and a decrease in volume

Answer 18

hydration of ions is exo
shorter bonds between ions and water mol