Past paper 1 lost marks

Question 1

what is the formula for Fe(I),Fe(II),Fe(III)

Answer 1

Fe^+,Fe^2+,Fe^3+

Question 2

what is Hydroxide charge and formula

Answer 2

(OH-)

Question 3

what is the Nitrate charge and formula

Answer 3

(NO3-)

Question 4

what is the Carbonate charge and formula

Answer 4

(CO32-)

Question 5

what is the Sulfate charge and formula

Answer 5

(SO42-)

Question 6

what is the Ammonium charge and formula

Answer 6

(NH4+)

Question 7

Write an ionic equation for the neutralisation of hydrochloric acid with potassium hydroxide

Answer 7

H^+ + OH^- ———> H2O

Question 8

Explain why sodium oxide has a high melting point

Answer 8

there are strong Ionic bonds that have strong electrostatic attraction and are in a giant ionic lattice

Question 9

In an Evaluation question what should you keep in mind sometimes when dealing with the products in a table

Answer 9

that the products come together not separate

Question 10

give two observations you could make when a small piece of potassium is added to water

Answer 10

because it’s a small piece it fizzes
* (potassium) floats
* (potassium) melts
* (potassium) moves around
* potassium becomes smaller
* (lilac) flame
* effervescence

Question 11

quickly make a drawing in head of what an ionic bond between sodium and oxygen looks like in a dot and cross diagram

Question 12

how should the filtrate be evaporated gently

Answer 12

water bath

Question 13

what are all the diatomic ions

Answer 13

have no fear of ice cold bear

H2,N2,F2,O2,I2,Cl2,Br2

Question 14

In electrolysis when does hydrogen form on the the cathode/negative electrode

Answer 14

when the hydrogen is less reactive than the metal

Question 15

why does copper not react with hydrochloric acid

Answer 15

because copper is less reactive than the hydrogen it cannot displace it

Question 16

why does copper carbonate + copper oxide only with hydrochloric acid make copper salt with no by product of copper like copper + copper carbonate only

Answer 16

because copper carbonate + copper oxide are bases which react with acid to make salt and hydrogen gas while copper + copper carbonate makes salt but also a by product of copper that didn’t displace with hydrogen as it’s less reactive

Question 17

molten lead bromide, bromine is produced at the positive electrode. complete the half equation for the production of bromine you should balance the half equation

Br^- ——> +

Answer 17

2Br^- —–> Br2 + 2e^-

Question 18

explain to me the double replacement reaction of MgO(s) + H2SO4(aq) →

Answer 18

it’s a (metal oxide + acid → salt + water) reaction

so the reaction is MgO + H2SO4 → MgSO4 + H2O when the MgO has a +0 charge, the Mg dicplaces the H2 which makes SO4 ^2- and then Mg leave’s the O and becomes Mg^+2 which bonds with SO4^-2 making a neutral bond MgSO4, And the O reacts with the H2 to make H2O

Question 19

some some of the copper produced did not stick to the negative electrode but fell to the bottom of the Beaker suggest how the students could find the total mass of the copper produced

Answer 19

Filtre the mixture, wash the and dried the copper residue, where the copper collected, after increasing mass

Question 20

what should you do when drawing exothermic graph

Answer 20

label the activation energy and the energy released

Question 21

how do you work out the number of atoms in something

Answer 21

mole’s * 6.02*10^23

Question 22

Acid + metal

Answer 22

salt + H2

Question 23

Acid + metal hydroxide

Answer 23

salt + water

Question 24

Acid + metal oxide

Answer 24

salt + water

Question 25

Acid + metal carbonate

Answer 25

salt + water + carbon dioxide

Question 26

Acid + metal hydrogen carbonate

Answer 26

salt + water + carbon dioxide

Question 27

Acid oxide + base

Answer 27

salt + water

Question 28

what is Ammonium charge and symbol

Answer 28

NH4^+

Question 29

Nitrate formula and charge

Answer 29

NO3^-

Question 30

Carbonate

Answer 30

CO3^2-