Practice Questions 4

Question 1

07.4 (Simple particle model for hydrogen gas)

Give two limitations of this simple particle model for hydrogen gas

Answer 1

1. hydrogen isn’t shown as H2

2. does not show speed between particles

Question 2

The hydrogen gas needed to power a car for 400km would occupy a large volume
What is one way the vol.could he reduced

Answer 2

Store it as a liquid

Question 3

08.1 multiple choice.

What is the state of bromine at 0 degrees and at 100 degrees

Answer 3

Liquid and gas

Question 4

What is the trend in boiling points of the halogens shown in table 5

Answer 4

Boiling points increase going down the group because The relative formula mass increases

Question 5

Why is it not correct to say that the boiling point of a single bromine molecule is 59 degrees

Answer 5

Boiling point is related to intermolecular forces and so more than one molecule is involved

Question 6

Iron reacts with each of the halogens on their gaseous form

Give one reason why this experiment should be done in a fume cupboard

Answer 6

The gas could be harmful

Question 7

Explain why the reactivity of the halogens decreases going down the group

Answer 7

Down the group outer electrons become further away from nucleus

So less attraction for outer electrons

So electron is obtained less easily

Question 8

08.6 mole question

Do working out and both answers (ratio and equation for the reaction

Answer 8

Moles for Fe = 4.48/56=0.08

Moles for Cl = 8.52/35.5 = 0.24

Fe:Cl=0.08:0.24. =1:3

Equation for reaction equals

2Fe + 3 CL2 ——–>2 FeCL3

Question 9

09.1

Suggest one reason for an anomalous result

Answer 9

Didn’t stir solution as much as necessary

Question 10

09.4 another calculation question do working out and answer

Calculate mass in grams

Answer 10

Moles = 192

Moles= 250/1000 x 0.0500= 0.0125

0.0125 x 192. =. 2.4g

Question 11

09.5. Titration question required prac.

Describe how the student would complete the titration

Answer 11

Add the citric acid until there is a colour change but when there is a slight colour change do it drop by drop (make sure this is on a white tile)

Measure the amount of citric acid needed for the colour change

Question 12

09.6

Give two reasons why a burette is used for the citric acid solution

Answer 12

More accurate than a measuring cylinder

Can add the citric acid in small volumes at a time

Question 13

What is the mole triangle

Answer 13

Mass
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Moles. X. Atomic mass