How was your chemitry paper?

[Nerdz]

Its was easier than expected but I got a lot wrong! :/ I usually get C in chemistry but I am really really hoping for an A

 

[yentaokia]

I wrote 2 answers for that. Surface area and catalyst

 

[yentaokia]

Can somebody tell me what u wrote for question 5 about the decomposition of nickel carbonyl and the next part about the method to remove impurities.

 

[aneeq247]

For decomposition, you have to heat it. I wasnt sure about the impurities part, so i just wrote that they had to be filtered off.

 

[Nerdz]

and how do you get ammonium sulfate using ammonia?

 

[rhoveesh]

Ammonia + sulfurice acid - precipitation

 

[rhoveesh]

*sulfuric

 

[Nerdz]

*sulfuric

i wrote ammonia and sodium sulfate and i wrote the crystalization process! so my answer is wrong?

 

[yentaokia]

ammonia+ sulfuric acid = ammonium sulphate which is soluble in water. How can it be precipitate?

 

[yentaokia]

they had asked how can we measure rate of reaction in another way ?? any other way to measure rate was asked ....not Surface Area or catalyst ..
i wrote ..rate can be found my measuring the change in temprature using Thermocouple ( since it is very senstive ) and secondly ...mass of iron left .

I didn't read the question carefully, 1 mark lost

 

[ritesh isuri]

Ammonia + sulfurice acid - precipitation

it is not a precipitation reaction it is a titration!! aqueous ammonia is an ALKALI and sulphuric acid is an ACID!!!

 

[ritesh isuri]

what did u write for .......in the question ...where we had to tell that ... describe another way to calculate the rate of reaction ?

by measuring the time taken for the bromine to decolorize(change from reddish brown to colourless)

 

[ritesh isuri]

does anybody know what the answer about the isotope of alumium should be?

 

[Miss_Z]

I'm really confused about the isotope thingy, I put 13 and 14 but my friends are saying it's 13 and 13 or 13 and 15. I'm so scared. Does somebody have a certain answer? T_T

 

[Miss_Z]

by measuring the time taken for the bromine to decolorize(change from reddish brown to colourless)

Are you sure about this answer? I wrote the same thing but I'm really uncertain. All others seem to have referred to mass/temperature.

 

[aneeq247]

I'm really confused about the isotope thingy, I put 13 and 14 but my friends are saying it's 13 and 13 or 13 and 15. I'm so scared. Does somebody have a certain answer? T_T

Id go with your friends, since and isotope has the same no of protons and a diff. no of nuetrons, and 13 protons plus 14 nuetrons are in the original atom of aluminium, so they cant be used.

 

[aneeq247]

an*

 

[aneeq247]

I'm really confused about the isotope thingy, I put 13 and 14 but my friends are saying it's 13 and 13 or 13 and 15. I'm so scared. Does somebody have a certain answer? T_T

your friends are right

 

[ritesh isuri]

Are you sure about this answer? I wrote the same thing but I'm really uncertain. All others seem to have referred to mass/temperature.

i am not sure of anything but i had just put an answer but if BrFe2 is colourless then i see no reason why cambridge will not accept the answer!!1

 

[ritesh isuri]

your friends are right

r u really sure that its 13 and 15 because thats what i have put but all my friends had used the 13 and 14