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P1 MCQ's preparation thread for chemistry ONLY!!!!

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w08 : 1 : 13 and 14 please help i think it's kind of a base knowledge question yet i don't know it help

no 13 : which oxide will produce the most acidic solution with water ?
A-co B-CO2 C-SiO2 D- P2O5

n0 14 : which salt is produced when amonia is added to aqueus sulpher dioxide until jest alkaline ?
A- NH4SO3
B- NH4 SO4
C - (NH4)2SO3
D- (NH4)2SO4

answer to 14 is c why sulphite not sulphate ?!
1. Write a balanced equation and use the mole ratios.
13. The oxides of Period 3 elements get more acidic as you go across the period.
14. Sulphur dioxide in aqueous solution gives sulphite ions, and sulphur trioxide gives sulphate ions.
 
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The apparatus shown is used for reflux. Reaction 1 is nucelophilic substition and reaction 2 is oxidation of an alcohol; both these need reflux. The 3rd is the bromine water tes; it occurs at room temperature.

its not reflux its distillation ka apparatus! I 'm sure about that
 
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A benzene molecule is like this:
stereochem_str5.GIF
. The Carbon atom you marked has a double-bond, therefore has only 3 groups attached to it & can't be chiral. It helps to remember that benzene isn't chiral, no matter which Carbon you refer to (they all have double-bonds anyway).


Thanks .
Your explanation was very helpful .
 
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1. Write a balanced equation and use the mole ratios.
13. The oxides of Period 3 elements get more acidic as you go across the period.
14. Sulphur dioxide in aqueous solution gives sulphite ions, and sulphur trioxide gives sulphate ions.
thank uuuu very very very very much :)
 
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3 : answer is b cause it says 2nd ionisation energy is higher than neighbours meaning that the 2nd electron is removed from lower orbital so outer orbital is all removed when only 1 electron is removed the only one with 1 e- in outer most orbital is b

17 . ligand is an ion with lone pair of electron that forms a dative bond .... chlorine ions have outer most shell so it's AG ions ........ not sure of the explanation but ligand definition sure.

20 : cis trans isomer gives 2 isomers , structrural isomers gives 2 more from which one is included in the cis trans so 4-1 = 3 isomers

structural isomers are ccl2ch2 and chcl-chcl , 2nd one is used in cis and trans

hope that helps
 
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3 : answer is b cause it says 2nd ionisation energy is higher than neighbours meaning that the 2nd electron is removed from lower orbital so outer orbital is all removed when only 1 electron is removed the only one with 1 e- in outer most orbital is b

17 . ligand is an ion with lone pair of electron that forms a dative bond .... chlorine ions have outer most shell so it's AG ions ........ not sure of the explanation but ligand definition sure.

20 : cis trans isomer gives 2 isomers , structrural isomers gives 2 more from which one is included in the cis trans so 4-1 = 3 isomers

structural isomers are ccl2ch2 and chcl-chcl , 2nd one is used in cis and trans

hope that helps
 

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3 : answer is b cause it says 2nd ionisation energy is higher than neighbours meaning that the 2nd electron is removed from lower orbital so outer orbital is all removed when only 1 electron is removed the only one with 1 e- in outer most orbital is b

17 . ligand is an ion with lone pair of electron that forms a dative bond .... chlorine ions have outer most shell so it's AG ions ........ not sure of the explanation but ligand definition sure.

20 : cis trans isomer gives 2 isomers , structrural isomers gives 2 more from which one is included in the cis trans so 4-1 = 3 isomers

structural isomers are ccl2ch2 and chcl-chcl , 2nd one is used in cis and trans

hope that helps


Thanks.
It was very helpful.
 
Messages
93
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3 : answer is b cause it says 2nd ionisation energy is higher than neighbours meaning that the 2nd electron is removed from lower orbital so outer orbital is all removed when only 1 electron is removed the only one with 1 e- in outer most orbital is b

17 . ligand is an ion with lone pair of electron that forms a dative bond .... chlorine ions have outer most shell so it's AG ions ........ not sure of the explanation but ligand definition sure.

20 : cis trans isomer gives 2 isomers , structrural isomers gives 2 more from which one is included in the cis trans so 4-1 = 3 isomers

structural isomers are ccl2ch2 and chcl-chcl , 2nd one is used in cis and trans

hope that helps


I am a bit confused in (3) qs.
(3) Why can't A be the correct answer?
It's difficult for me to choose between A and B.
 
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any body can help me in S09:11 ?

(11) qs says that unreactive gas is produced , so answer can't be A and B because NO and O2 are both reactive.
But N2 is reactive so answer can be either C or D.
But since the reaction is highly exothermic(lot of heat energy given out),so any nitrate products will decompose too, so D is not an answer too, as Al(NO)3 will decompose, so then Al(NO)3 can't be shown as product in equation.
No nitrate products are present as products in C .
So this leaves C as the correct answer.
 
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