Fuuuuckkkiiiiiiinnnn

Question 1

1.1 Give the number of electrons and neutrons in the aluminium atom

Answer 1

13

14

Question 2

1.2 Aluminum is produced by the reduction of aluminum oxide (Al2O3). What is meant by the term reduction?

Answer 2

loss of oxygen

Question 3

1.3 Explain why the positive carbon electrodes must be continually replaced.

Answer 3

at high temp oxygen reacts with carbon electrode so the positive electrode burns away to produce co2

Question 4

1.4 Carbon electrode (made from graphite)…….
Molten mixture of aluminium oxide and cryolite………..
Metal wire…………..

Answer 4

delocalised electrons
ions
delocalised electrons

Question 5

2.1 Suggest one limitation of using a ball and stick model for a water molecule.

Answer 5

its not to scale

Question 6

2.2 Ice has a low melting point because theintermolecular forces are……………..

Answer 6

weak

Question 7

2.3 What is the molecular formula of the molecule in Figure 3?

Answer 7

CH40

the 4 is meant to be small not big 4

Question 8

2.4What is the number of bonds formed by each carbon atom in diamond?

Answer 8

4

Question 9

2.5 Give twophysical properties of diamond

Answer 9

very hard

high melting point

Question 10

2.6 Name two other substances with giant covalent structures.

Answer 10

graphite

silicon dioxide

Question 11

3 Plan a method the students could use to test their hypothesis (6 mrks)

Answer 11

1.weigh test tube
add metal carbonate
weigh test tube and metal carbonate

2 .heat
allow it to cool
weigh test tube and metal oxide
repeat until no change in mass

Question 12

4.1 Complete the equation for the reaction by writing the state symbols.
ZnO( ) + 2HCl( ) → ZnCl2( ) + H2O( )

Answer 12

ZnO(s) + 2HCl(aq) → ZnCl2(aq) + H2O(l)

Question 13

4.2Give one way that the student could speed up the reaction between zinc oxide powder and hydrochloric acid

Answer 13

heat the mixture

Question 14

4.3 How could the student know when all the hydrochloric acid has reacted?

Answer 14

the solid remains

Question 15

4.4 How could the student obtain zinc chloride solution from the reaction mixture when all the hydrochloric acid has reacted?

Answer 15

filter it out

Question 16

4.5 Describe how zinc chloride crystals are produced from zinc chloride solution.

Answer 16

heat it then leave it to cyrstalise

Question 17

4.6 pH at start =

pH atend =

Answer 17

12

2

Question 18

4.7 Complete the symbol equation for the preparation of sodium sulfate.
….NaOH + H2SO4 →……….+……….

Answer 18

2NaOH + H2SO4 →NA2SO4 + 2H20

Question 19

4.8 What was the hydrogen ion concentration of the hydrochloric acid after water had been added?

Answer 19

0.10mol/dm^3

Question 20

5.1 What is the dependent variable in this investigation?

Answer 20

temperature change

Question 21

5.2 Suggest why the copper sulfate solution was left for four minutes before adding the magnesium.

Answer 21

to reach a constant temperature

Question 22

5.5 Explain why the temperature of the mixture decreases after 7 minutes.

Answer 22

the reaction is finished so energy is lost to surroundings

Question 23

5.6 Suggest the identity of metal Q. Give one reason for your answer.

Answer 23

Zinc

less reactive than magnesium

Question 24

5.7A copper sulfate solution contained 0.100 moles of copper sulfate dissolved in 0.500 dm3 of water. Calculate the mass of copper sulfate in 30.0 cm3 of this solution. Relative formula mass (Mr): CuSO4 = 159.5

Answer 24

(moles= 30/500 x 0.1)=0.06

0.06 x 159.5= 0.957

Question 25

6.1 What two conclusions can be made from the results? Tick two boxes

Answer 25

Atoms have a positively charged nucleus

Mass is concentrated in the nucleus in the centre of atoms

Question 26

6.2The gold foil is 4.00 × 10^–7m thick and 2400 atoms thick. What is the diameter of one gold atom in metres? Give your answer to 3 significant figures.

Answer 26

4x10^-7
———– = 1.67x10^-10
2400

Question 27

6.3 0.175 g of gold reacts with chlorine.The equation for the reaction is :2 Au + 3 Cl2→ 2 AuCl3 Calculate the mass of chlorine needed to react with 0.175 g of gold.Give your answer in mg Relative atomic masses (Ar): Cl = 35.5 Au = 197

Answer 27

0.175/197= 0.000888
0.000888 x 3/2=0.00133
0.00133x71=0.0946g
=94.6mg

Question 28

7.1 Explain what happens to caesium atoms and to oxygen atoms when caesium reacts with oxygen to produce caesium oxide

Answer 28

caesium loses an electron
then oxygen atom gains 2 electrons
so two caesium atoms react with one oxygen atom to form CS+ and 02-
extra notes: caesium has positive charge and vice versa at the end of reaction

Question 29

7.2 Explain why caesium is more reactive than sodium.You should answer in terms of electrons.

Answer 29

caesium has more energy levels
so the outer electron is further from the nucleus
so weaker attraction between the two
so the outer electron is more easily lost

Question 30

Explain why the early periodic tables placed iodine (I) before tellurium (Te), but then Mendeleev placed tellurium before iodine.

Answer 30

early periodic tables were arranged in order of atomic weight
idodine has a lower atomic weight than tellurium
so mendeleev placed iodine with elements of the same properties