Chemistry: Post your doubts here!

[Namehere]

CH3CH=CHCHO
140 degree + Ni + H2
what will be result?
CH3CH2CH2CHO or CH3CH2CH2CH2OH

Second option is correct.

 

[mehria]

sorry i meant does H2 and Ni catalyst reduce CHO?

yes... these reagents cnvert alkenes into alkanes n carbonyl compounds into alcohol..
where as NiBH4 n LiALH4 can only reduce carbonyl compounds

 

[robinhoodmustafa]

sorry i meant does H2 and Ni catalyst reduce CHO?

no. H2 and Ni only reduces Alkenes to alkanes

btw check this image. I found it in a doc. It summarizes which and what get oxidize and reduce.

 

[Batguy]

elimination, reduction or hydrolysis or dehydration!!! i need differences between them en reagents used for these reactions

 

[robinhoodmustafa]

yes... these reagents cnvert alkenes into alkanes n carbonyl compounds into alcohol..
where as NiBH4 n LiALH4 can only reduce carbonyl compounds

we say the same thing at same time

 

[Batguy]

elimination, reduction or hydrolysis or dehydration!!! i need differences between them en reagents used for these reactions

robinhoodmustafa plzz

 

[mehria]

we say the same thing at same time

no.. i said that H2 n Ni reduces both alkenes n carbonyl compounds... n u said that they only reduce alkenes...

 

[MiniSacBall]

no.. i said that H2 n Ni reduces both alkenes n carbonyl compounds... n u said that they only reduce alkenes...

He said at the same time not thing

 

[mehria]

He said at the same time not thing

he said that: the same thing at the same time
read his post again...

 

[MiniSacBall]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s09_qp_2.pdf
Second Variant
Q5
I didn't understand the question itself is it saying 2CH3CHO Or just CH3CHO
And i need help for part a)

he said that: the same thing at the same time

oh XD
Sorry, when i read fast i make mistakes.

 

[mehria]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s09_qp_2.pdf
Second Variant
Q5
I didn't understand the question itself is it saying 2CH3CHO Or just CH3CHO
And i need help for part a)


oh XD
Sorry, when i read fast i make mistakes.

its ok... first i thought that i've made mistake


n for Q5 (a) whenever the formula is CnH2nO2 then its either carboxylic acid or an ester... but for ths part as it is sayng that it must contain -OH group then u have to draw the structural formula for the carboxylic acid...

2 is the mole of CH3CHO that is chngng into one mole of C4H8O2

 

[robinhoodmustafa]

robinhoodmustafa plzz

Elimination. A functional groups gets replaced by another group

Reduction is gain of hydrogen by the removal of oxygen
Oxidation is gain of oxygen and loss of Hydrogen
(OIL-RIG)

Hydrolysis bond formation with the elimination of a water molecule

and dehydration is pulling back h20 from the compound (H and OH) -Removing H


Elimation. Can be Halogens (I , Br , Cl)
Reduction. NABH4 . LiAlH4 , Zn, H2
Oxidation : Kmno4 , K2Cr2O7 , H2so4

Hyrdrolysis. Agno3 , H20

Dehyrdration : H3PO4 , H2so4

 

[robinhoodmustafa]

no.. i said that H2 n Ni reduces both alkenes n carbonyl compounds... n u said that they only reduce alkenes...

Oh yes yes.
Carbonyl back to Alcohol .NaBH4 ( Hyrdrogen involved )

btw

Suchal Riaz

 

[Batguy]

Elimination. A functional groups gets replaced by another group + creating water

Reduction is gain of hydrogen by the removal of oxygen
Oxidation is gain of oxygen and loss of Hydrogen
(OIL-RIG)

Hydrolysis bond formation with the elimination of a water molecule

and dehydration is pulling back h20 from the compound (H and OH) -Removing H


Elimation. Can be Halogens (I , Br , Cl)
Reduction. NABH4 . LiAlH4 , Zn, H2
Oxidation : Kmno4 , K2Cr2O7 , H2so4

Hyrdrolysis. Agno3 , H20

Dehyrdration : H3PO4 , H2so4

dun u think!! elimination is more than substitution u told :'|

 

[Namehere]

Oh yes yes.
Carbonyl back to Alcohol .NaBH4 ( Hyrdrogen involved )

btw

Suchal Riaz

I did say second option was correct ^^

 

[robinhoodmustafa]

dun u think!! elimination is more than substitution u told :'|

As far as I have read.

Elimination . Is the removal of two substituent from an organic compound
and in Substitution only single substituent in removed.

It relates to SN1 and SN2 mechanism .

 

[Batguy]

As far as I have read.

Elimination . Is the removal of two substituent from an organic compound
and in Substitution only single substituent in removed.

It relates to SN1 and SN2 mechanism .

elimination = dehydration my teacher said me once :'| it creates double bond no? :'|

 

[Batguy]

Sn1 Sn2 relates neucleophiles en electrophiles :'( no?

 

[robinhoodmustafa]

elimination = dehydration my teacher said me once :'| it creates double bond no? :'|

Elimination removes two units while dehydration removes only Hyrdrogen.

comparison b/w sub and eli

 

[Adiizz]

Aslm...
What does this part of the chemistry syllabus means? "(h) show understanding of, and use, the Brønsted-Lowry theory of acids and bases, including the use of the acid-I, base-II concept"
What's the acid-1, base 11 concept means?