Chemistry P1 and P2 today

[farhan141]

Crap I messed it up. My Oxygen Bonds were in the last Carbon.

 

[Imran Nagi]

Btw isn't P2 supposed to be 2hours? It was 1h30min

u gave chemistry paper first time...I mean not in school?

 

[farhan141]

We used to get 2 hours in O1 and O2

u gave chemistry paper first time...I mean not in school?

 

[Shadow]

Here's the structure.
http://www.google.com.pk/imgres?img...a=X&ei=LH-fUZrRDNOthQe4qIHgAg&ved=0CDEQ9QEwAQ

Just like that i drew an xtra hydrogen bond in between but then cut it with a pencil, vil they penalize me for that?

 

[altox876]

The mass of the tablet was o.500 grams. It contained 0.312 grams of CaCO3, according to my calculations.

I attempted this question and my answer was .4 g I think. From the graph the volume of CO2 evolved was 96 cm. So the moles of CO2 would be 96/24000=.004 moles
In the next part as the molar ratio of CaCO3 to CO2 is according to this equation CaCO3 + 2HCl=CaCl2 + H2O + CO2 1:1 so
0.004 * CaCO3 MR
0.004 *100=0.4 g

 

[Shadow]

meny to theek bnaaya

Taaliyan !!

 

[Saad Mughal]

Just like that i drew an xtra hydrogen bond in between but then cut it with a pencil, vil they penalize me for that?

You used pen for the drawing?

 

[farhan141]

Hope my structure's correct.

 

[Shadow]

You used pen for the drawing?

drew it with pencil first, then re-drew with pen ... den i realized one bond was wrong so had to cut it with pencil

 

[Saad Mughal]

drew it with pencil first, then re-drew with pen ... den i realized one bond was wrong so had to cut it with pencil

Then it's no issue. I just drew with a dark pencil.

 

[Shadow]

Then it's no issue. I just drew with a dark pencil.

Sure that using pen in drawings is allowed?

 

[Saad Mughal]

Sure that using pen in drawings is allowed?

Yeah, it should be.

 

[Shadow]

Yeah, it should be.

i hope so ..

 

[Saad Mughal]

i hope so ..

It is. The paper says 'you MAY use a soft pencil for diagrams' which means that you can use a pen too.

 

[Shadow]

It is. The paper says 'you MAY use a soft pencil for diagrams' which means that you can use a pen too.

Yup, thats xactly y i used a pen, plus a frnd of mine said that the image is not completely clear in scanning if drawn with pencil .. so i was just thinking that y take the risk

 

[Imran Nagi]

We used to get 2 hours in O1 and O2

that's why u suffered in externals

 

[Saad Mughal]

Yup, thats xactly y i used a pen, plus a frnd of mine said that the image is not completely clear in scanning if drawn with pencil .. so i was just thinking that y take the risk

That's not the case either, even an ordinary house-hold scanner can scan the images quite clearly. They use much better scanners.

 

[AbbbbY]

Sure that using pen in drawings is allowed?

I drew in pen, mostly, in my O's. Just used a pencil for graph work.

 

[Fraze]

And yet.. I stand here. Hoping that someone got this right.

got that right... it wasnt that hard though i mean for it to be anitrate there had to be aluminium powder too but it gave ammonia with NaOH only which means it was NH4. The rest of the atoms left i.e. V and 3O constituted the other ion bcoz at o levels papers they can only expect us to predict two ions per compound and hence the VO3. Btw.. i saw ur posts on the english thread. You seem like an A star student

 

[Saad Mughal]

got that right... it wasnt that hard though i mean for it to be anitrate there had to be aluminium powder too but it gave ammonia with NaOH only which means it was NH4. The rest of the atoms left i.e. V and 3O constituted the other ion bcoz at o levels papers they can only expect us to predict two ions per compound and hence the VO3. Btw.. i saw ur posts on the english thread. You seem like an A star student

Well, hoping for A*'s in these CIE's. INSHA ALLAH. Thanks for the complement.
Yeah, two things;
- No aluminium was mentioned.
- They asked the TWO ions that were present in the compound.
Gave off the answer to be Ammonium ion and Metavanadate ion.