Chemo P5 tips

[nealDSA]

It Means "Confused" =P !!

 

[MukeshG93]

It is the energy gained per unit mol, so if you use more mols, you will get more energy right? So, to find how much energy one mol gives you have to divide the total by the number of mols.

 

[abrraza]

is dat acid or base?? or no. of moles of water produced?

 

[MukeshG93]

it depends on what you want to calculate. If it is the neutralization of the acid, use the acid, if base use base

 

[blueindigo]

plz plz in jun 08, Q2f, how do u find the value of x????????/ and relative formula mass?????
its urgent plz!!!

 

[nealDSA]

I've The Same Doubt .. But Nobody Bothers To Explain :sorry: :unknown:

 

[blueindigo]

PLzzz.... help ppl, theyre 5 ppl whom i know who dont get it either and this is srsly driving our brains off,..cmon guys...few hours til lwe have our exam!!!!!!QUICK!!!!

 

[MukeshG93]

plz plz in jun 08, Q2f, how do u find the value of x????????/ and relative formula mass?????
its urgent plz!!!

After heating, all of the CO2 and water vaporise and they go, so only the mass of CuO remains. Use the data to find the mol of CuO for a value that is on the line of best fit. Then, since 1 mol of CO2 is produced with 2 mol of CuO, you can find the amount of CO2 that has been produced. Subtract the mass of the CO2 that has been produced from the mass lost due to heating and you find the mass of water. Use the mass of water to find the mol of water. There, now you have x.

 

[blueindigo]

so what did u take for the x axis and y axis????????
and these values will give mass of CuO???????

 

[MukeshG93]

I took the mass of the basic carbonate used for the x axis as that was the independent variable and I took the mass of residue after heating for the y axis. If the basic carbonate is heated, the products are CuO, CO2 and H2O. H2O vaporises due to the heat, CO2 is a natural gas so the residue would be made up of CuO only. That's the mass of CuO. If you calculate the mol of CuO, you can find the mass of CO2 that evolved with it. Hence, after subtracting the mass of CuO + mass of CO2 from the mass before heating, you get the mass of water. Find the mol of water and equate with the x + 1 thing to get the value of x.

 

[WellWIshER]

GUYS CAN SOMEONE plz xplain

oct n09 52

how to make dioc acid????? :Bravo: :O:

 

[zeebujha]

BEST OF LUCK EVERYONE!!!!!!!!!!!!HOPE ALL OF YOU ACE P5!!!!!!!!!!!!!

 

[utsav156]

Okay guys, just over with P5. Let me put down whatever I understood from the P5s of M/J 2002 to O/N 2010 into words. Hopefully someone can correct me when I make mistakes and yeah add to what I have written (of course!)

For planning section:

1. When asked to draw a diagram, ALWAYS mention the volume of the apparatus being used. The one most often used is gas syringe. I think it is better to limit the volume of syringe to less than 500 cm3 . Also, the volume of a commonly used small test tube is around 16 cm3 and that of a boiling tube is about 25 cm3. We always have to keep the volume of the apparatus we are using while choosing the volume of the solution for the planning. Saying that we are going to place 50cm3 of aqueous HCl in a test tube is of course not going to please the examiners. I think I ended up doing the same in one of the papers where we had to prepare different concentrations of a given solution. I chose volume of water to be added to a beaker to be 250 cm3. However, the ER stated that the volume should be less than 200cm3, that so being since the volume of a commonly used glass beaker is around 250cm3. Someone carrying out my expm would have a fully filled beaker. However, we can use greater volume if we state that the volume of the beaker is 400cm3 or 500 cm3 or so on. So, stating the volume of the apparatus is very very important

Pranav ryt???? ty bro help me a lot!!!

 

[MukeshG93]

Damn, it's time. I haven't looked at all of the past papers at all. I hope I will be able to use my brain to pull off at least a 25 for that A* my grades are hanging on, need it desperately! Although I'm sure P4 will put A LOT less pressure. We need to do this for P4 as well! Then I won't have to waste time browsing through the past papers when the whole directory is already over here! We don't need any tough questions today, so guys, pray to god that it won't be a mess. God Bless!

 

[cieko..]

thanx a lot..
it helped a lot in today's exam..
i wouldn't be able to solve it without ur help...
thnxxxxxxx

 

[zeebujha]

thanx a lot..
it helped a lot in today's exam..
i wouldn't be able to solve it without ur help...
thnxxxxxxx

my pleasure man!

 

[zeebujha]

So, guys, how was the paper?? Hope all of you rocked!!!!!!!

 

[cool]

plz pray for me...paper went very bad ...it cud have been much better..i don't know wat happened to me....wats the GT for A normally..and dis time ppr was easy.

 

[AN10]

i drew a curve instead of straight line what do u think how many marks will i lose

 

[ParanoidAleveler]

i drew a straight line
wasnt it supposed to be a curve?