Chemistry P1 and P2 today

[Shadow]

i wrote nh4+ (4 idk wht lame reason) i jst thought ammonia will be produced so ammonium ions will be there and 4 the other ion i wrtoe al+3 cx of tht nitrate ion test v learnt...when sodium and aluminium ions come in contact ammonia is produced...but i guess i was applying the wrong concept at the wrong place

U mentioned the first one correct but dude aluminium was not even used

 

[TheStallion-Reborn]

U mentioned the first one correct but dude aluminium was not even used

i knw but the liberation of ammonia made me thnk so...

 

[Shadow]

i knw but the liberation of ammonia made me thnk so...

Yea the tests for ammonium n nitrates r quite similar, just a single difference of aluminium powder

 

[Saad Mughal]

in my center the generator does come on ALMOST immediately but sometimes theres 1-2 min gao b/w the switch.....should I b rebellious over this?

Same here; IF ever the light goes.

 

[Saad Mughal]

the question was>?

The ions present in H4NO3V.

 

[Saad Mughal]

i dnt thnk so..... i wrote smthng else..i dnt remember wht but it wasnt calcium cx i wrote calcium and then was conviced due to some stupid reason tht it cldnt b calcium...

Calcium Hydroxide IS SOLUBLE.

 

[TheStallion-Reborn]

Calcium Hydroxide IS SOLUBLE.

The ions present in H4NO3V.

aaaaaa.....4get it! its done! check out the physics chem bio thread 4 a query i posted a while ago.... thankies

 

[Saad Mughal]

I can't understand it.
I'll get back to you.

 

[danial 234]

i

+ electrons flow in every direction but electric kettle produce charges and negative charge repel electrons so electrons move in other direction but electrons do move towards the negative charge and positive. electrons move 2 way in ac but the negative charge forces electrons to change direction

think that ques asked abt electron movement regarding heat transfer not about current

 

[Kinza Zimri]

are you talking about the last part of b10??

Exactly! the last part :'( 3 marks, gone, just like that.

 

[TheStallion-Reborn]

Exactly! the last part :'( 3 marks, gone, just like that.

same here...though i did do it! but i did it after the time was over,,,did the steps etc but im 100000000% sure its wrong... bullshit i wrote!

 

[Kinza Zimri]

exactly my case

and maybe i could have concentrated more and i wouldnt have made those silly mistakes i did :/

 

[Kinza Zimri]

same here...though i did do it! but i did it after the time was over,,,did the steps etc but im 100000000% sure its wrong... bullshit i wrote!

maybe something might be correct after the time was over? how? they allowed you? I couldnt concentrate on it! my mind had suddenly stopped working, i knew i wont be able to find the answer at that point. 3 marks!!!!

 

[Kinza Zimri]

U mentioned the first one correct but dude aluminium was not even used

it was worth how many marks?

 

[ReN0uNeD De\/!|_]

thanku soo much hope u also get more than u expect good luck

Thnxx...

 

[*Anonymous*]

Am I the only one that got this right?

I got it that too...!

 

[Shadow]

it was worth how many marks?

i think 2, 1 for each ion

 

[Shadow]

in previous years ac dc questions came in chemistry so these currents r in the syllabus see for your self in past pprs and sciences r sciences in chemistry proton electrons and neutrons r basic chapter. same is the cas with phys it also contains these things in last chap. a kettle runs on AC not DC and when heated Ac currents vary so do the movement of electrons

I did chem past pprz till 2005, did not cum across any such ques. The only topic in which v relate electricity with battery supply is electrochemistry. For movement of electrons, we just need to know they move from negative to positive. N about those electric kettles, they can work perfectly on D.C supply as well

 

[Aly Emran]

ok to sum up p2:
A1. sulfur, calcium, barium, iron, carbon, lithium, ammonia,
A2. scientist r worried of increased pollution and depleting fossil fuel, C6H12O6+ 6O2--->6CO2+ 6H20, energy evolved during bond making is greated than energy absorbed during bond breaking, diagram exothermic
A3. al is positive and lose three electrons as metal r positive too and lose electrons(I- and Br- opposite of this statement), stronge forces in solid and weak in liquid + vibrate at fixed position in solids and move freely in liquid, IBr I-Br(make sure u make dot cross diagram this is just to provide example), Bromine decolourise from brown, al is a low density metal, oxide layer prevent reactions.
A4. Fractional distillation and boiling point, Reaction of cracking, Polymer structure (idk), steam + phosphoric acid and 300*C 50-70 atm
A5. Emperical formula to show H4NO3V, it acts as a catalyst or coloured compound, NH4+ & VO3-, oxidise because it reduces, ammonia
A6. iron reduce as it gain electrons, iron excess, pink deposits and green ppt, reaction occurs
B7. Flask + syringe+ stopwatch+ burette, Mg(OH)2 + 2HCl -----> MgCl2 + 2H20 & CaCO3+ 2HCl ------> CaCl2 + Co2 + H2O , 0.004 moles, 0.4g, increase concentration more fruitful collisions
B8. (not done)
B9. C H O , Propanol, C10H22O, No trend shown, Butyl Ethanoate, K2CrO7 and heat under reflux, CO and h20
B10. Mg2+ & O2- , Mg give 1 more electron to oxygen than sodium to chlorine, solid- ions fixed & molten- ions free to move, Ag2(aq)+, 2Cl-(aq)---->AgCl2(s), 0.15g(not confirmed about this)
+ why carboxlyic acid do not combust??

 

[Shadow]

check mj 2003

p1 or p2? which ques?