AQA GCSE Chemistry Paper 1 Higher Tier Triple (8462 1H) - 17th May 2024 [Exam Chat]

Reply 180

10

I understand where all the confusion is now. Some people think that overall energy change being positive means that you have to flip the symbol into a negative so that it fits an exothermic reaction. But others and I used the idea that reactants - products = 2219, so rearranged it to find the reactants. It seems strange to change the question where it says the overall energy change is 2219 to -2219 to fit the question.

Reply 181

Sobbingsoobin

14

Original post by bencolls

my answers i can think of
392.4 for bond
9000dm^3 for volume of gas
72.4% for iron
electrolysis practical- attach cell to electrodes in solution add voltmeter in parallel and decrease concentration by adding water and measure voltage
30cm^3 for the volume of gas on the last couple of pages

i got all of those!!!

Reply 182

Daniboynah

11

Original post by starryspinn

Does anyone remember the volume of gases question? ended up with 4000 not 9000, and trying to work out where I went wrong with it,

not supposed to multiply mr by 2

Reply 183

amanahh

11

Original post by anseil248

It was 5 I think

oh then I must've got at least 4 then phew

Reply 184

rinni

8

Original post by mango night

I understand where all the confusion is now. Some people think that overall energy change being positive means that you have to flip the symbol into a negative so that it fits an exothermic reaction. But others and I used the idea that reactants - products = 2219, so rearranged it to find the reactants. It seems strange to change the question where it says the overall energy change is 2219 to -2219 to fit the question.

it was definitely -2219 cus the question said the reaction was exothermic. exothermic reactions only have negative values for energy change

Reply 185

Sobbingsoobin

14

Original post by starryspinn

Does anyone remember the volume of gases question? ended up with 4000 not 9000, and trying to work out where I went wrong with it,

So i forgot the actual question, but i remember getting 250 for the moles of the reactant, which you had to times by 3/2 to get the moles of the product which was 375, then u times by 24 which they gave u in the question which was 9000