GCSE Chemistry Paper 1 UNOFFICIAL MARKSCHEME

Q1.1 Metal carbonate, metal hydroxide could be metal too.
Q1.2 Ca(CO3)2
Q1.3 (Dilute acid) dilute sulfuric acid and magnesium oxide. Heat up the dilute acid with bunsen burner for a few seconds. Then you can get a flask and stir with a glass rod.Both the dilute acid and magnesium oxide till it has all reacted which you can tell if excess magnesium oxide goes to the bottom of the flask. Filter with filter paper and funnel. Afterwards you can put it in a evaporating basin and heat up with a water bath or bunsen burner till some of the water formed has evaporated and leave the solution for crystals to form.

NOT 100% SURE BUT:
Bond energies: 290

pH: 5

Electrolysis would not work because: ions in solid zinc chloride are not free to move so they cannot carry charge
Improvement to electrolysis: use delivery tubes & measuring cylinders OR gas syringe to measure volume of gas and prevent any escaping

Last question: 0.126

NOT endothermic becase: temperature increase shows it was exothermic

Hydrogen fuel cell: 2H2 + O2 ---> 2H2O
6 mark: info from table - conclusion needed I think??
extra info: hydrogen fuel cells prodce only water - harmless product // electric batteries eventuallt run out because they can store less energy each time they're recharged // electric batteries are polluting to dispose of // hydrogen is reactive- must be compressed, hard to store

Strong but dilute acid:
strong acid fully ionises in water for form H+ ions
dilute acid- low concentration of acid molecules (ie watered down)

Alkaline batteries cannot be reversed: reactional inside cells is not reversible

Plum pudding: B (can't remember)
Alpha particle experiement: C
Niels Bohr: A
Chadwick: discovered the existence of neutrons / isotopes= atoms of the same element with same no. of protons but different no. of neutrons (therefore different atomic MASS) // the existence of neutrons explained why atoms of the same element could have different masses

Chlorine more reactive than iodine because: fewer number of shells- easier to gain electrons because the positive charge of the nucleus has stronger electrostatic forces to the outermost shell of negative electrons, to attract an extra one

Iron Pyrite: FeS2

TiCl4- not expected to be liquid at room temperature because: it has strong ionic bonds held together by strong electrostatic forces between titanium and chlorine ions. these strong forces require a lot of energy to overcome. Expected: solid compound.

Q1. Metal carbonate, metal hydroxide could be metal too.
Q2. Ca(CO2)3
Q3. (Dilute acid) dilute sulfuric acid and magnesium oxide. Heat up the dilute acid with bunsen burner for a few seconds. Then you can get a flask and stir with a glass rod.Both the dilute acid and magnesium oxide till it has all reacted which you can tell if excess magnesium oxide goes to the bottom of the flask. Filter with filter paper and funnel. Afterwards you can put it in a evaporating basin and heat up with a water bath or bunsen burner till some of the water formed has evaporated and leave the solution for crystals to form.
LAST Q. I got 0.0113 rounded however I am not sure.
Please leave what you think you got for questions you remember below.
This is all I remember.