Chemistry: Post your doubts here!

[nehaoscar]

Why not D?? is sulfate soluble?? How??

 

[nehaoscar]

Why not C?

 

[shazmina]

View attachment 54733
Why C?? And Why not B??

K+ ion has lost 1 electron and now it contains only 18 electrons .. with 19 protons
S3- Ion has gained 3 electrons and now it contains 19 electrons along with 16 protons
Since K+ ion contains more protons ie higher +ve charge than S3- ion it will attract its electron more strongly than S3- ion
Coming to S3- ion, it has gained 3 electrons and now there will be greater repulsion between the gained electrons while keeping the same proton number and hence less attraction ... this is why S3- ion is larger than k+ ion

 

[nehaoscar]

How 6?? What happens when you react it with H2SO4??

 

[nehaoscar]

How is 2 correct? Why are they both metals?
And why is 3 wrong? They both form +2 so can they not be in the same group?

 

[nehaoscar]

Why is 2 correct?

 

[shazmina]

View attachment 54738
Why not C?

When Hydrocarbons are burnt CO2 and H2O will be given out & so we are not sure which Hydrocarbon was burnt. ( 1st statement )
Alcohols and Carboxylic acid react with PCl5 and liberate White fumes of HCl so again we are not sure which compound is it ( 2nd Statement )
Only Aldehydes and ketones react with 2,4 DinitrophenylHrdrazine, and hence we can be sure that this compound X wasnt an Aldehydes or a ketones

 

[nehaoscar]

I know why only 2 and 3 are correct but i want to know where will the Ca join on?
Like Na joins the COO- , where will Ca join since it requires -2 charge to join??

 

[nehaoscar]

When Hydrocarbons are burnt CO2 and H2O will be given out & so we are not sure which Hydrocarbon was burnt. ( 1st statement )
Alcohols and Carboxylic acid react with PCl5 and liberate White fumes of HCl so again we are not sure which compound is it ( 2nd Statement )
Only Aldehydes and ketones react with 2,4 DinitrophenylHrdrazine, and hence we can be sure that this compound X wasnt an Aldehydes or a ketones

Oh carboxillic acids also react with PCl5 Pcl2 SoCl2 etc..?

 

[BhaiArshad]

Explain?

 

[BhaiArshad]

Help?

 

[nehaoscar]

Explain?

If it's A
Then Kp = P.H20 x P.CO / P.H2 x P.CO2
You know the P.H2 and P.CO is 10000Pa each
And Kp is 0.288
So
P.H20 x P.CO = 10000 x 10000 x 0.288
Now the molar fraction for CO and H2O is the same so the Partial pressure will be same
So square root 10000 x 10000 x 0.288
which gives A

 

[shazmina]

Oh carboxillic acids also react with PCl5 Pcl2 SoCl2 etc..?

yes

 

[shazmina]

http://s21.postimg.org/vl3ml18xy/new_one.jpg
qwertypoiu The Sarcastic Retard can you please help me with this question ...
As far as i know, secondary alcohols when oxidised to ketones donot respond to mild oxidising agents, so i thought it might be a secondary alcohol, but is it wrong? can you pls clarify, the ans is D

 

[Bilal.khan]

http://s21.postimg.org/vl3ml18xy/new_one.jpg
qwertypoiu The Sarcastic Retard can you please help me with this question ...
As far as i know, secondary alcohols when oxidised to ketones donot respond to mild oxidising agents, so i thought it might be a secondary alcohol, but is it wrong? can you pls clarify, the ans is D

The question says that it is unreactive towards mild oxidising agents which mean it can not be a primary or a secondary alcohol as both can be oxidised .
It has to be a tertiary alcohol which is only possible in D

 

[Bilal.khan]

Can someone please tell the names of the gasses and the reagents used for driying them... please

 

[nehaoscar]

Why not A?? Densities are not in the syllabus ?

 

[The Sarcastic Retard]

View attachment 54750
Why not A?? Densities are not in the syllabus ?

MP & BP of Y < Z
Mg has 2+ charge and Na has +1 charge...
Mg needs more heat energy...
Na < Mg

 

[nehaoscar]

N forms 2 bond pairs and 1 lone pairs here right??
Then why 120degrees? wouldn't it be A?

 

[nehaoscar]

MP & BP of Y < Z
Mg has 2+ charge and Na has +1 charge...
Mg needs more heat energy...
Na < Mg

But then Al<Si is also there right? So why not A?