Chemistry MCQ thread...

[Abdulrab]

yes marking scheme gives A as the answer . i myself am confused

 

[Zishi]

please help me with june 06 question 38.

It's B, because as HBr can add into double bonds, so DBr can also add into them...Option 3 shows nuceophlic substitution reaction which can only be done with cyanide ions.

 

[Zishi]

yes marking scheme gives A as the answer . i myself am confused

Tell me the year and question number. I want to see the question and Mark scheme myself.

 

[kakarocks]

why 2 is wrong ?

The mixtures are being distilled as well , read the question

 

[kakarocks]

why it is not D !!

It's not C because ethene is a gas , it's not D because esters dont react with NaOH . It could be A or B not too sure wether alcohols reach with NaOH . I think its A

 

[Zishi]

yes marking scheme gives A as the answer . i myself am confused

Dude, please confirm it from mark scheme before posting anything here. I've searched all the papers, found this question, and mark scheme says C. Please don't do this again. This messes up minds of everyone here.

 

[Abdulrab]

hav u done june 06 Q 36 ?? if yes then please explain it to me !!

 

[Zishi]

hav u done june 06 Q 36 ?? if yes then please explain it to me !!

1 and 2 are correct. Ammonia accepts a proton to form ammonium ion, so option 2 is correct. Also ammonia is oxidised to nitrogen gas, so it acts as a reducing agent.

 

[xHazeMx]

does ethanoic acid dissolve completely in water? and does it form hydrogen bonds with water molcules ?

 

[xHazeMx]

what could be the answer and why ?

 

[sakibfaiyaz]

what could be the answer and why ?

should be D.....making it more alkaline means adding -OH.....therefore according to Le Chatliers principal, the -OH should be converted to oppose the change....this shifts the equilibrium to the right....therefore more V2+

 

[Hateexams93]

Cl2 + H2SO4 is this reaction even possible ?

 

[libra94]

no i dont think so, cuz both of them are good oxidising agents, so there'll be no redox reaction
and the products formed will be Cl2SO4? lol i dont think so tht this reaction is possible

 

[Hateexams93]

its so confusing -.-

 

[Hateexams93]

Which mixtures, on heating, produce the gas ND3?
[D = H 2
1 , an isotope of hydrogen]
1 CaO(s) and ND4Cl(s)
2 CH3CN and NaOD in D2O
3 NDH3Cl and NaOD in D2O
WHY 3 IS WRONG ???? I thought it will produce NH3 AS WELL

 

[Xthegreat]

in 3 there is only 1 D, where to find the other 2? they want ND3 not NH3

 

[ambitious1]

Chlorine compounds show oxidation states ranging from -1 to +7.

What are the reagent(s) and conditions necessary for the oxidation of elemntal chlorine into a copound containing chlorine in the +5 oxidation state?

A AgNO3(aq) followed by NH3 at room temperature.
B conc. H2SO4 at room temperature.
C cold dilute NaOH(aq)
D hot concentrated NaOH(aq)


With explanation please. =)

 

[asrathor]

a

 

[hassam]

well ans to this question...is hot conc. NaOH which reacts to form NaClO3....THIS is a reaction u shud have memorised during ur chemistry course

 

[ambitious1]

Nope, the answer is D. Can someone please explain why is it so?