Chemistry: Post your doubts here!

[abbas haider]

The question states which of these combinations can form from cracking so we can make multiple combinations for example:
CH3(CH2)5CH=CH2 = CH3(CH2)2CH3 + CH2=CHCH=CH2
which now proves Z is correct.
CH3(CH2)5CH=CH2 = CH3CH=CH2 + CH2=CH2 + CH2=CHCH3
Similarly X and W is proved.
CH3(CH2)5CH=CH2 = CH3CH2CH3 + CH2=C=CH2 +CH2=CH2
Y proved.
Hope it helps ^^

Actually in cracking reactions you can make any alkane or alkene (given that no of carbon atoms and hydrogen atoms are less or equal to the reactant (Alkane Or Alkene )

Btw I thaught only cracking of alkanes is possible.... anyidea if cracking of Alkynes or Arenes possible or not???

 

[Kanekii]

Need Help with these :3

 

[Metanoia]

No it's A
How are the bonds supposed to break in this compound?

Theoretically, as long as the products have same or lesser carbons than the original molecule, they can be formed upon cracking

 

[Metanoia]

Well for 33 it is D? I'm not sure tho let take an option 2 which is not possible bcoz it is reversible reaction so it can shift backward so less so4 is formed

H2SO4 + aq => H^+ + H2SO4^-
Due to full dissociation at the first stage, from 1 mole of H2SO4, we will get 1 mole of H+ and 1 mole of HSO4^-

HSO4^-(aq) <=> H^+(aq) + SO4^2-
Due to partial dissociation at the second stage, from 1 mole of HSO4^-, we will get << 1 mole of H+ and << 1 mole of SO4^2-

Therefore
[SO4^2- (aq)] is low
[HSO4^-(aq)] >> [SO4^2-(aq)]

 

[Metanoia]

Actually in cracking reactions you can make any alkane or alkene (given that no of carbon atoms and hydrogen atoms are less or equal to the reactant (Alkane Or Alkene )

Btw I thaught only cracking of alkanes is possible.... anyidea if cracking of Alkynes or Arenes possible or not???

Yes, possible to crack with enough energy. But the issue is that they do not yield products of much commercial value in most cases

 

[aisya farooq]

Plz help me with these

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Plz help me with these

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enthalpy change of Hydration is always exothermic. hence reaction 2 is exothermic

 

[A*****]

Need Help with these :3View attachment 63745 View attachment 63744

At 1200, the bond is C-O
At 3400, it is O-H and since there is no other absorption mentioned, so it can not be a carboxylic acid, therefore, its just an alcohol
according to the formula, there are 4 isomers

 

[A*****]

Need Help with these :3View attachment 63745 View attachment 63744

For 9, the bonds being broken are 1 C=C and 1 H-Br and those forming are 1 C-C, 1 C-H and 1 C-Br
Enthalpy change = +610 +366 -350 -410 -280 = -64

 

[Kanekii]

At 1200, the bond is C-O
At 3400, it is O-H and since there is no other absorption mentioned, so it can not be a carboxylic acid, therefore, its just an alcohol
according to the formula, there are 4 isomers

Thanks a bunch

 

[Kanekii]

For 9, the bonds being broken are 1 C=C and 1 H-Br and those forming are 1 C-C, 1 C-H and 1 C-Br
Enthalpy change = +610 +366 -350 -410 -280 = -64

Oh i get it now i just missed to add C-C single bond

 

[aisya farooq]

Element J is a solid. It occurs as a contaminant of fossil fuels. Its oxide K is formed in car engines. In the atmosphere, K can be further oxidised to L. Which statements about J, K and L are correct? 1 Atoms of J have paired p electrons. 2 The atmospheric oxidation of K to L is a catalysed reaction. 3 With water, L forms a strong acid.
the answer is A how is option 1 correct? help!

 

[A*****]

Element J is a solid. It occurs as a contaminant of fossil fuels. Its oxide K is formed in car engines. In the atmosphere, K can be further oxidised to L. Which statements about J, K and L are correct? 1 Atoms of J have paired p electrons. 2 The atmospheric oxidation of K to L is a catalysed reaction. 3 With water, L forms a strong acid.
the answer is A how is option 1 correct? help!

J is sulfur which has 6 electrons in its outer shell...2s and 4p so 1p orbital has 2 electrons

 

[aisya farooq]

J is sulfur which has 6 electrons in its outer shell...2s and 4p so 1p orbital has 2 electrons

but two electrons the the p subshell are unpaired

 

[A*****]

but two electrons the the p subshell are unpaired

But atleast it has SOME paired electrons, which makes the statement correct

 

[A*****]

Why can't it be A?

 

[Kanekii]

Why can't it be A?

Its B and its not A as catalyst increases rate but does not effect equilibrium so it can be seen that the it is referring to equilibrium due to pressure still being high enough. Besides im pretty sure catalyst were used that time as well for this reaction unless they were invented recently xD.

 

[aisya farooq]

But atleast it has SOME paired electrons, which makes the statement correct

oh makes sense. thanks

 

[A*****]

Can someone plz explain statement 2 and 3? How is 2 wrong?

 

[Mts.99]

has chemistry threshold ever crossed 200 for A*?

 

[Kanekii]

Can someone plz explain statement 2 and 3? How is 2 wrong?

There can be no acid base reaction between bases and bases. Statement 2 is wrong as Sulfuric acid is an oxidising agent and can oxidise ethanol whilst being reduced in the process meaning it lost proton/H+ ion