Hydrogenation of Alkynes

Q. Consider the reactions :(0) (CH3)2CH-CH2Br \xrightarrow{c2h5oh} (CH3)2CH-CH2OC2H5 +HBr (ii) (CH3)2CH- CH2Br \xrightarrow{c2h5o-}(ch3)2ch-ch2oc2h5 + br- the mechanisms of reactions (i) and (ii) are respectively(1) SN2 and S N2 (2) SN2 and SN1 (3) SN1 and SN2 (4) SN1 and S1

Q. What happen when but-2-yne reacts with Lindlar's catalyst?

1. Alkynes doesnot react with lindlar's catalyst
2. Formation of n-butane takes place
3. Formation of cis-but-2-ene takes place
4. Formation of trans-but-2-ene takes place

Q. Isobutane is subjected to bromination. The major product is

1. Isobutyl bromide
2. Tert-butyl bromide
3. Both are equally formed
4. Isobutyl bromide slightly in excess

Q. Which one of the following has the smallest heat of hydrogenation per mole?

1. 1- butene
2. trans-2-butene
3. cis-2-butene
4. 1, 3-butadiene

Q. An alkene ‘A’ (Mol. formula $C_5{H}_{1}0)$ on ozonolysis gives a mixture of two compounds ‘B’ and ‘C’. Compound ‘B’ gives positive Fehling’s test and also forms iodoform on treatment with $I_2$ and$NaOH.$ Compound ‘C’ does not give Fehling’s test but forms iodoform. Identify the compounds A, B and C. Write the reaction for ozonolysis and formation of iodoform from B and C.

Q. Which of the following is the most stable product of the following reaction?

1. 
2. 
3. 
4. 

Q. Which process converts olefins into parafins

1. Hydrogenation
2. Hydrolysis
3. Halogenation
4. Dehydration

Q. The reduction of 4-octyne with $H_2$ in the presence of $Pd/BaS{O}_4$ and quinoline gives:

1. trans-4-octene
2. cis-4-octene
3. a mixture of cis and trans-4-octene
4. a completely reduced product $C_8{H}_{18}$

Q. Identify the product in the given reaction:

1. 
2. 
3. Both (a) and (b)
4. None of these

Q. For the given reaction :
$Ca{C}_2+2H_{2}O\stackrel{\Delta }{⟶}A\stackrel{\text{Red hot Fe tube}}{\to }\underset{\text{Major}}{B}$
The major product B is :

1. Toluene
2. Ethylbenzene
3. Butyne
4. Benzene

Q. $S_{N}1$ & $S_{N}2$ product are same in (excluding stereoisomer):

1. 
2. 
3. 
4. 

Q.

Oils are converted into fats by

1. Decarboxylation

2. dehydrogenation

3. hydration

4. hydrogenation

Q. By which reagent alkyne converts to cis-alkene?
i.e. $C_6{H}_{11}-C\equiv C-C{H}_3\stackrel{R}{⟶}\text{cis-alkene}$:

1. $C{r}_2{O}_3/A{l}_2{O}_3$
2. $H_2,Pd/BaS{O}_4$
3. $Na/dryether$
4. $Na/N{H}_3\left(l\right)$

Q. The reduction of 4-octyne with $H_2$ in the presence of $Pd/BaS{O}_4$ and quinoline gives:

1. a mixture of cis and trans-4-octene
2. a completely reduced product $C_8{H}_{18}$
3. cis-4-octene
4. trans-4-octene

Q. tertiary alcohol +al2o3/△

Q. Phenetole on cleavage with $HI$ gives:

1. 
2. 
3. 
4. 

Q. In the following reaction:
$C_2{H}_2\underset{333K}{\overset{HgS{O}_4/H_{2}S{O}_4}{\to }}\left(X\right)\rightleftharpoons C{H}_{3}CHO$ What is (X) ?

1. $C{H}_{3}C{H}_{2}OH$
2. $C{H}_2=CH-OH$
3. $C{H}_{3}C{H}_{2}CHO$
4. $C{H}_3-O-C{H}_3$

Q. Reaction of acetylene and propyne with $HgS{O}_4$ in presence of $H_{2}S{O}_4$ produces respectively.

1. Acetone and acetaldehyde
2. Acetaldehyde and acetone
3. Propanaldehyde and acetone
4. Acetone and propanaldehyde

Q. Addition of water to acetylene compounds is catalysed by _____ and ______

1. $HgS{O}_4$ and dil. $H_{2}S{O}_4$
2. $KMn{O}_4$
3. $H_{2}S{O}_4$
4. Both (b) and (c)

Q. Consider the following reaction,
Major product (P) formed is
[0.77 Mark]

1. 
2. 
3. 
4. $C{H}_3–C{H}_2–CH=C{H}_2$

Q. Oils are converted into fats by

1. Hydration
2. Decarboxylation
3. Hydrogentation
4. Dehydrogenation
5. Hydrogenolysis

Q. The ene-yne that produces a chiral compound upon treatment with Lindlar's catalyst is:

1. 
2. 
3. 
4. 

Q.

Why is Wurtz reaction not preferred for the preparation of alkanes containing odd number of carbon atoms? Illustrate your answer by taking one example.

Q. In the reaction with HCl, an alkene reacts in accordance with the markovnikov's rule, to give a product 1-chloro-1-methylcyclohexane. The possible reaction alkene is :

1. 
2. 
3. 
4. 

Q. What would be the major product of the following reaction? Which of the following is true?

1. The degree of unsaturation in the major product is 1
2. The degree of unsaturation in the major product is 3
3. The degree of unsaturation in the major product is 4
4. The exo double bond of the major product is cis

Q. What would be the major product of the following reaction? Which of the following is true?

1. The degree of unsaturation in the major product is 1
2. The degree of unsaturation in the major product is 3
3. The degree of unsaturation in the major product is 4
4. The exo double bond of the major product is cis

Q. When propyne is treated with aqueous $H_{2}S{O}_4$ in the presence of $HgS{O}_4$, the major product is:

1. Propanal
2. Propyl hydrogen sulphate
3. Acetone
4. Propanol

Q. The alkene that has greatest negative heat of hydrogenation among the following is:

1. 
2. 
3. 
4. 

Q.

In the following question two Statement-I (Assertion) and Statement-2 (Reason) are provided. each question has 4 choices (a), (b), (c) and (d) for its answer, out of which Only One is correct. Mark your responses from the following options:
Statement-1: 2-Pentyne on hydrogenation in presence of Lindlar catalyst gives cis-1-pentene.
Statement-2: Addition of hydrogen is a stereospecific reaction.

1. Both Statement-1 and Statement-2 are true and Statement-2 is the correct explanation of Statement-1.
   

2. Both Statement-1 and Statement-2 are true and Statement-2 is not the correct explanation of Statement-1.
   
   

3. Statement-1 is true but Statement-2 is false.
   

4. Statement-1 is false but Statement-2 is true.

Q. Addition of water to acetylene compounds is catalysed by _____ and ______

1. $HgS{O}_4$ and dil. $H_{2}S{O}_4$
2. $KMn{O}_4$
3. $H_{2}S{O}_4$
4. Both (b) and (c)