Dehalogenation of Vicinal Dihalide

Q. In the following sequence of reactions,
$C{H}_{3}Br\stackrel{KCN}{\to }A\stackrel{H_3{O}^{+}}{\to }B\underset{LiAl{H}_4}{\overset{Ether}{\to }}C$
The end product $C$ is:

1. Acetone
2. Methane
3. Acetaldehyde
4. Ethyl alcohol

Q. The process through conversion of 2, 3-dibromobutane to 2-butene with Zn dust takes place:

1. Dehydrogenation
2. Dehydrohalogenation
3. Dehalogenation
4. Denaturation

Q. Choose the appropriate answers: Lanthanides on reaction with

1. Carbon form $Ln{C}_2$
2. Nitrogen form $LnN$
3. Water give $Ln(OH{)}_3$ and hydrogen gas
4. Oxygen forms $LnO$

Q. When ethylene bromide is treated with Zn, we get

1. Alkane
2. Alkyne

3. Alkene

4. All

Q. Which of the following compounds can be classified as allylic halides?

1. A and C
2. B and C
3. A and D
4. B and D

Q. Explain the mechanism of the following reactions:
$C{H}_3-C{H}_2-OH\underset{443K}{\overset{H^{+}}{\to }}C{H}_2=C{H}_2+H_{2}O$

Q. if isopropyl chloride and ethyl chloride both react with Na in the presence of ether which alkanes are obtained 1.n-butane 2.2-methyl butane 3.2, 3 dimethyl butane 4.all

Q. The structure of allyl vinyl thioether is

1. $C{H}_2=CH-C{H}_2-S-C{H}_2-CH=C{H}_2$
2. $C{H}_2=CH-S-C{H}_2-CH=C{H}_2$
3. $C{H}_2=CH-S-CH=C{H}_2$
4. None of these

Q. A sample of 2, 3-dibromo-3-methylpentane is heated with zinc dust. Identify which is the structure that represents the organic product formed in the reaction.

1. 
2. 
3. 
4. 

Q. Which of the following is with highest and lowest floculation value among Al3+, Na+, Mg2+, Ba2+. 1) Al3+, Na+ 2)Na+, Al3

Q. xC3H8 +yO2 zCO2 +qH2O Find n-factor for C3H8, O2, CO2, H2O in the reaction.

Q. Which compounds do not give Lassaigne test for nitrogen?

1. $C_6{H}_5{N}_{2}Cl$
2. ${NH}_2-{CH}_2-COOH$
3. ${NH}_{2}OH$
4. ${CH}_{3}CO{NH}_2$

Q. Consider the following transformation.
$C{H}_{3}COOK\stackrel{CaC{O}_3}{\to }\begin{array}{c}A\end{array}\stackrel{\text{heat}}{\to }\begin{array}{c}B\end{array}\underset{NaOH}{\overset{I_2}{\to }}\begin{array}{c}C\end{array}$
The molecular formula of $\begin{array}{c}C\end{array}$ is:

1. $C{H}_3-\underset{I}{\underset{|}{\stackrel{OH}{\stackrel{|}{C}}}}-C{H}_3$
2. $IC{H}_2-COC{H}_3$
3. $CH{I}_3$
4. $C{H}_{3}I$

Q. Pick up the major product in the following elimination reaction:

1. 
2. 
3. Both will be formed in equal amounts
4. Third product having rearranged skeleton will be formed.

Q.

Ethylidene chloride is an ______

1. Vic-dihalide

2. Gem-Dihalide

3. Allylic halide

4. All of these

Q. Predict a dihalide which gives ethene by treating with Zn dust under suitable conditions.

1. 2, 4-dibromo-3-methylpentane
2. 1, 2-dibromoethane
3. 1, 4-dibromomethylpentane
4. 1, 3-dibromo-2-methylbutane

Q. The process through conversion of 2, 3-dibromobutane to 2-butene with Zn dust takes place:

1. Dehydrogenation
2. Dehydrohalogenation
3. Dehalogenation
4. Denaturation

Q. When ethylene bromide is treated with Zn, we get

1. Alkane

2. Alkene

3. Alkyne
4. All

Q. Which of the following diborane $\left(B_2{H}_6\right)$ structure contains:

1. Four $2c-2e^{-}$ bonds and four $3c-2e^{-}$ bonds
2. Two $2c-2e^{-}$ bonds and two $3c-3e^{-}$ bond
3. Two $2c-2e^{-}$ bonds and four $3c-2e^{-}$ bonds
4. Four $2c-2e^{-}$ bonds and two $3c-2e^{-}$ bond

Q. In the following sequence of reactions,
$C{H}_{3}Br\stackrel{KCN}{\to }P\stackrel{H_3{O}^{+}}{\to }Q\underset{LiAl{H}_4}{\overset{Ether}{\to }}R$
The end product $R$ is:

1. Acetone
2. Methane
3. Acetaldehyde
4. Ethyl alcohol

Q. Which of the following is monoatomic

1. Nitrogen
2. Fluorine
3. Ne
4. Oxygen

Q. Identify $X$ in the following sequence of reactions.

Q. For the given reaction :


Which of the following correctly represents (A) and (B)?

1. (A) is $Zn/Zndust$ , and (B) is 1-bromopropane.
2. (A) is $Zn/Zndust$ , and (B) is propene.
3. (A) is $ZnO$ , and (B) is 1-bromopropane.
4. (A) is $ZnO$ , and (B) is propyne.

Q. The reaction
$RN{H}_2+CH{Cl}_3+3KOH⟶RNC+3KCl+3H_{2}O$ is known as

1. Carbylamine reaction
2. Nogmann's reaction
3. Victor Meyer's reaction
4. Cannizzaro reaction

Q. Predict a dihalide which gives ethene by treating with Zn dust under suitable conditions.

1. 2, 4-dibromo-3-methylpentane
2. 1, 2-dibromoethane
3. 1, 4-dibromomethylpentane
4. 1, 3-dibromo-2-methylbutane

Q. Which of the following regarding Be and Al is incorrect?

1. Both have the same electronegativity
2. Carbides of both liberate ethyne when treated with water
3. Both react with alkali to form beryllate and aluminate
4. Nitrides of both liberate when treated with water

Q. Identify X and Y in the following reaction sequence.

1. $(C{H}_3{)}_{2}CHCHB{r}_2$, $(C{H}_3{)}_{2}C=C{H}_2$
2. $(C{H}_3{)}_{2}CHC{H}_{2}Br$, $C{H}_{3}CH=CHC{H}_3$
3. $(C{H}_3{)}_2\underset{Br}{\underset{|}{C}}HC{H}_3$, $C{H}_{3}CH=CHC{H}_3$
4. $(C{H}_3{)}_{2}CHBrC{H}_{2}Br$, $(C{H}_3{)}_{2}C=C{H}_2$

Q. Nitrates of a group $I$ metals (except $Li$) decompose into the nitrites rather than oxides. This may most probably due to the fact that:

1. doubly charged anions like $C{O}_3^{2-}$ and not singly charged anions like nitrates decompose to give oxides
2. nitrite anion has approximately same size as that of group I cations
3. $O^{2-}$ is doubly charged and hence would make the salt less stable than singly charged nitrite $\left({N{O}_2}^{-}\right)$ ion
4. group I metal ions have relatively larger size compared to that of ${N{O}_2}^{-}$ ion

Q. Whan alkane react with nitrating mixture which product is form?

Q. $C{H}_3-C{H}_2-\stackrel{Cl}{\stackrel{|}{C}}H-C{H}_3\stackrel{alc.KOH}{\to }\left(A\right)$
The major product 'A' is:

1. $C{H}_3-C{H}_2-CH=C{H}_2$
2. 
3. 
4. All in equal amount