Chemistry: Post your doubts here!

[saudha]

It shud be either C or D cuz only Temperature has an effect on equilibrium constant. I guess its C cuz if you lower temperature , rate of forward reaction increases since its exothermic and KC also increases. Cuz KC = [H2O][CH3COOC2H5]/ [C2H5OH][CH3COOH]
So since forward reaction is more, [H2O][CH3COOC2H5] will have higher value and [C2H5OH][CH3COOH] lower value.

thxx

 

[Most_UniQue]

thxx

My pleasure and mind answering my question which is on previous page?

 

[Most_UniQue]

The esterification reaction
Ammonia is manufactured on a large scale by the Haber process.
In a particular plant, conditions of 400 °C and 250 atm in the presence of an iron catalyst are
used.
N2(g) + 3H2(g) 2NH3(g) ∆Ho = –92kJmol–1
What could contribute most to increasing the equilibrium yield of ammonia?
A adding more catalyst
B increasing the pressure to 400atm
C increasing the temperature to 1000°C
D using air rather than nitrogen
some one pls explain these question to me!

Answer is B . Adding catalyst just increases rate of reaction by lower activation energy. C cant be cuz reaction is exothermic so it favors low temperature otherwise equilibrium will be shifted to the left . D is impossible.
So its B , in haber process the pressure required is 400*C .

 

[Oliveme]

Hydrolyze the ester to get CH3OH and CH3CH2CH2CO2H (so 3 is obviously wrong). Product #2 will be formed, but it doesn't distill off so you only have the alcohol in the distillate. It's also worth noting that if there was another option - CH3CHH2CH2CO2H in the question, that wouldn't be found in the distillate either because all of it would have been converted into the salt.

The answer is D.

thank you

 

[saudha]

Someone help me with this question! How can i find number of isomers?
View attachment 8582

i think C is right and that is bcoz......to find this there is a way..... the formula is 2^(no of double bonds)....in thsi question...
double bonds=3
so 2^3=8 and so =3
C is the ans .... im guessing

 

[Most_UniQue]

i think C is right and that is bcoz......to find this there is a way..... the formula is 2^(no of double bonds)....in thsi question...
double bonds=3
so 2^3=8 and so =3
C is the ans .... im guessing

WOW cool! C is right! Tnx a lot! I didnt knew it was so easy!!

 

[user]

Assalamoalaikum wr wb!

need help with these mcqs

 

[Most_UniQue]

Assalamoalaikum wr wb!

need help with these mcqs

post ur question

 

[saudha]

plss help me with this Q

 

[saudha]

WOW cool! C is right! Tnx a lot! I didnt knew it was so easy!!

ur welcome....happy 2 help

 

[i love my country]

thanks for all who answered on my Questions great explaination

 

[user]

Assalamoalaikum wr wb!!

Check out this thread..may be makes some sense Tips for solving chemistry MCQs 9701/01

 

[user]

post ur question

Assalamoalaikum wr wb!

sorry...that was a mistake ...

 

[gary221]

Hey how do we solve this??​

​

Ans is D​

 

[hihi]

Hey,can anyone please explain the question number 13 in this paper??? i posted it before too. thanks.
http://www.xtremepapers.com/papers/... AS Level/Chemistry (9701)/9701_w10_qp_12.pdf

5 HIO = 2 I2 + HIO3 + 2 H2O

 

[user]

Aoa wr wb!

one more...

 

[user]

Hey how do we solve this??​

Ans is D​

Assalamoalaikum wr wb!

first one...has no hydrogen bonding...cuz that exists in NH3 or HF or -OH so not A

dimeric..i dunno...let's check the other options

N to Al is a dative bond and Al to H is 3 covalent bonds...so total of 6 + 2 = 8 electrons therefor not C

yes...cuz there are no lone pairs, and 4 atoms attached...so tetrahedral structure...

P.S. Note that when a dative bond is formed...the lone pair that takes part will be considered as a bond pair..not really related to this...but I guess it's an imp point...

 

[umarashraf]

Aoa wr wb!

one more...

View attachment 8609

its far too easy than the one you have answered... num of atoms = moles * Avogadro constant...
1g of Hydrogen has 1 mole... same as neon... 20/20.... moles= m/Mr

 

[user]

its far too easy than the one you have answered... num of atoms = moles * Avogadro constant...
1g of Hydrogen has 1 mole... same as neon... 20/20.... moles= m/Mr

lol...
but the thing is i cant figure out how 1 g of hydrogen is 1 mole...
1 mole of hydrogen is 2 g, right? :s

 

[umarashraf]

lol...
but the thing is i cant figure out how 1 g of hydrogen is 1 mole...
1 mole of hydrogen is 2 g, right? :s

you right mate... H2 has two hydrogen atoms... number of atoms will be 2*moles... for hydrogen 2*.5... for neon 1*1... for CO2 it will be 3*.5..(as carbon has 3 atoms , 2 of oxygen 1 carbon)