Addition Reactions

Q.

Which are free radical reactions

$I.C{H}_3-CH=C{H}_2+HBr\stackrel{Peroxide}{\to }C{H}_3-C{H}_2-C{H}_{2}BrII.C{H}_3-CH=C{H}_2+HBr\to C{H}_3-CHBr-C{H}_{3}III.C{H}_3-CH=C{H}_2+C{l}_2\to ClC{H}_2-CH=C{H}_{2}IV.C{H}_3-C{H}_3+C{l}_2\to ClC{H}_2-C{H}_3$

1. Only I

2. I, III and IV

3. III and IV

4. IV and I

Q. Pick out the correct reactions:
$A.C{H}_3-CH=C{H}_2+HCl⟶C{H}_3-\underset{Cl}{\underset{|}{C}}H-C{H}_3$
$B.C{H}_3-CH=C{H}_2+HBr⟶C{H}_3-C{H}_2-C{H}_{2}Br$
$C.C{H}_3-CH=C{H}_2+HBr\stackrel{peroxide}{\to }C{H}_3-C{H}_2-C{H}_2-Br$
$D.C{H}_3-CH=C{H}_2+HI\stackrel{peroxide}{\to }C{H}_3-\underset{I}{\underset{|}{C}}H-C{H}_3$

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

Q. 93. Monochlorination of n-Pentane gives 1-chloropentane (A), 2-chloro-pentane (B) and 3-chloropentane (C). The relative reactivity of 1^° : 2^° : 3^° hydrogen towards chlorination is 1 : 3.8 : 5. Which of the following statement(s) is/are true ? (a) Probability of formation of A is highest (b) Percentage of A, B and C will be 20.83, 52.78 and 26.39 respectively (c) Rate of reaction decreases with the addition of radical scavengers. (d) The order of stability of alkyl radicals formed as intermediate is • • CH3CHCH2CH2CH3 > CH3CH2CHCH2CH3 • > CH2CH2CH2CH2CH3

Q.

What happens when Chloroform is heated with Silver powder?

Q. 29. what products are formed when 1, 3-methylbenzene is treated with Br2 in the presence of FeBr3?

Q. What is the product of the reaction of 1, 3-butadiene with $B{r}_2$

1. 1, 4 –dibromobutene
2. 1, 2 -dibromobutene
3. 3, 4-dibromobutene
4. 2, 3-dibromo-2-butene

Q. The compound 2-Methylbut-2-ene on reaction with NaIO4 in the presence of KMnO4 give

Q. How electron gain enthalpy can be endothermic and exothermic?

Q. 42. Identify total number of mono chlorinated products when 2-methyl pentane react with Cl2/hv ?

Q. Friedel-Crafts reaction of bromobenzene with methyl chloride gives:

1. o-Bromotoluene
2. p-Bromotoluene
3. o- and p-Bromotoluene
4. m-Bromotoluene

Q. 9. 0.21 gm of but 3 yne 2 ol is treated with excess of C2H5MgBr at standard conditions. The volume of gas evolved is 1134.4 ml 2146.4 ml 3 67.2 ml 4 73.2 ml

Q. 23. Draw the Lewis dot structure of (1) HCLO4 (2) HNO (3) H3Po4 (4) H3PO3 (5) H2SO5.

Q. C-C(CN)-C(CHO)-C-C C-C(CHO)-C(CN)-C-C Is it position isomer

Q.

How are the following radicals represented: bicarbonate, phosphate, nitrate, bisulphate?

Q. What is the product when 2-Methyl-prop-1-ene is reacted with bromine water?

Q. Reaction of $B{r}_2$on ethylene in presence of NaClgives

1. $BrC{H}_2-C{H}_{2}Br$
2. $ClC{H}_2-C{H}_{2}Br$
3. Both (a) and (b)
4. None of these

Q.

A compound 'X' reacts with conc. Sulphuric acid to give an alkene. The alkene reacts with bromine and subsequent treatment of the product with alcoholic KOH yields propyne. The formula of the compound is

1. CH₃CH₂CH₂OH

2. CH₃CH₂CH₂Br

3. CH₃CH₂OH

4. CH₃OH

Q. The compound which obeys Markovnikov's rule when reacted with $HBr$ is:

1. 
2. 
3. 
4. 

Q. Presence of peroxides affects the addition of

1. HBr
2. HCl
3. HI
4. All of these

Q.

Which of the following is most reactive towards, Markovnikov addition?

1. 

2. 

3. 

4. 

Q.

In the reaction

$C{H}_{3}CHO+HCN\to C{H}_3-CH\left(OH\right)CN\underrightarrow{H+/H_{2}O}C{H}_3-CH\left(OH\right)COOH$

An asymmetric centre is generated. The acid obtained would be

1. 50% d + 50%l - isomer

2. 20% d + 80% l - isomer

3. d- isomer

4. l - isomer

Q. The major product obtained by the addition reaction of $HBr$ to 4-methylpent-1-ene in the presence of peroxide is:

1. 1-bromo-4-methylpentane
2. 4-bromo-2-methylpentane
3. 2-bromo-4-methylpentane
4. 3-bromo-2-methylpentane

Q. which of the following is acidic hydrocabon 1.ch3ch2ch2ch3 ;2)ch3 c ≡ cch3; 3)ch2=chch=ch

Q. why is tetrahydrofuran not an aromatic compound

Q. Acetylene reacts with ammonical Cu_{}Cl_2 to give precipitate of- -Red colour -yellow -white -blue Explan?

Q. An unknown compound has molecular formula $C_7{H}_{12}$. It gives two aldehydes shown below upon ozonolysis followed by work up with $Zn-H_{2}O$. What is the structure of the original compound ?

1. 
2. 
3. 
4. None of the above

Q. 56. Explain the hybridisation of Sulphur in SO2 molecule

Q.

Study the given paragraph(s) and answer the following questions.

Passage:

Markownikoff’s Rule:

When an unsymmetrical alkene or alkyne reacts with an unsymmetrical reagent, then the negative part of the reagent attaches to that carbon atom which contains a lesser number of hydrogen atoms during the addition.

For example:

${\mathrm{CH}}_3\mathrm{CH}={\mathrm{CH}}_2+\mathrm{HBr}\to {\mathrm{CH}}_3\mathrm{CH}\left(\mathrm{Br}\right){\mathrm{CH}}_3$

${\mathrm{CH}}_2={\mathrm{CH}}_2+\mathrm{HBr}\to {\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{Br}$

Markownikoff’s Addition:

The addition of $\mathrm{HBr}$(not $\mathrm{HCl},\mathrm{HI}\mathrm{and}\mathrm{HF}$) on alkenes in presence of peroxides takes place in anti-Markownikoff’s way (Peroxide effect).

${\mathrm{CH}}_3\mathrm{CH}={\mathrm{CH}}_2+\mathrm{HBr}\left(\mathrm{peroxide}\right)\to {\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{CHBr}$

Question statement:

Markownikoff’s addition is applicable to

1. Symmetric alkenes

2. Asymmetric alkenes

3. Both (a) and (b)

4. Neither (a) nor (b)

Q. 1.propene on reaction with HCL in presence of peroxide gives. 2.also in place of HCL if HI is substituted what is the product formed 3.does hcl and hi react the same as hbr reacts with propene is absence of peroxide 4.does hf give product with propene in presence and absence of peroxide

Q. 25. Find the number of molecules which is/are formed by p-p overlapping. HCl, Cl2, Br2, H2