Acidity of Alpha Hydrogens

Q.

Cross aldol between formaldehyde and acetaldehyde .

Q. $C{H}_{3}CHO+HCN\to C{H}_{3}CH\left(OH\right)CN\underset{H_{2}O}{\overset{H^{+}}{\to }}C{H}_{3}CH\left(OH\right)COOH$

In the reaction, an asymmetric centre is generated. The acid obtained would be:

1. 20% $d$ + 80% $l$ -isomer
2. $d$-isomer
3. $l$-isomer
4. 50% $d$ + 50% $l$-isomer

Q. $(C{H}_3{)}_{3}C-CHO$ does not undergo aldol condensation due to

1. Three electron donating methyl groups
2. Cleavage taking place between $-C-CHO$ bond
3. Absence of $\alpha -$hydrogen atom in the molecule
4. Bulky $(C{H}_3{)}_{3}C-$ group

Q.

How will you convert?

(i) Benzene into aniline

(ii) Benzene into N, N-dimethylaniline

(iii) Cl−(CH₂)₄−Cl into hexan-1, 6-diamine?

Q. The activating effect of $-NHCOC{H}_3$ group is ______ as compared to $-N{H}_2$ group.

1. less
2. same
3. more
4. very high

Q.

Which of the following is non-electrolyte

1. NaCl

2. CaCl₂

3. C₁₂H₂₂O₁₁

4. CH₃COOH

Q.

The oxidative cleavage of compounds Glucose (A) and Fructose (B) with $HI{O}_4$ leads to the formation of acids and aldehydes. The ratios of formic acid to formaldehyde for (A) and (B) respectively are

1. $\frac{5}{1},\frac{3}{2}$

2. $\frac{5}{2},\frac{3}{1}$

3. $\frac{3}{2},\frac{5}{2}$

4. $\frac{4}{2},\frac{5}{1}$

Q. In the following compound.


The favourable site(s) for protonation is/are:

1. (a) and (e)
2. (b), (c) and (d)
3. (a) and (d)
4. (a)

Q. In a set of reactions propionic acid yielded a compound D. $C{H}_{3}C{H}_{2}COOH\stackrel{SOC{l}_2}{\to }B\stackrel{N{H}_3}{\to }C\underset{B{r}_2}{\stackrel{KOH}{\to }}D$ The structure of D would be:

1. CH₃CH₂NH₂
2. CH₃CH₂CONH₂
3. CH₃CH₂CH₂NH₂
4. CH₃CH₂NHCH₃

Q. Which of the following compound(s) can undergo aldol condensation?

1. Phenyl acetaldehyde
2. 2-Methylpentanal
3. Benzaldehyde
4. 1-Phenylpropanone

Q.

What is the anhydride of H₃PO₃?

1. P₂O₄

2. P₄O₁₀

3. P₃O₅

4. P₄O₆

Q.

Base catalysed aldol-condensation occurs with:

1. Propionaldehyde

2. 2-methylpropionaldehyde

3. Benzaldehyde

4. 2, 2-Dimethylpropionaldehyde

Q. The following ether, when treated with HI produces –

1. 
2. 
3. 
4. 

Q. Which of the following compound will undergo self-aldol condensation in the presence of cold dilute alkali?

1. $C_6{H}_{5}CHO$
2. $C{H}_{3}C{H}_{2}CHO$
3. $HC\equiv CCHO$
4. $C{H}_2=CHCHO$

Q. Which acid has lowest $pK,$ value ?

1. Nitroacetic acid
2. Bromoacetic acid
3. Chloroacetic acid
4. Cyanoacetic acid

Q. The compound having most basic nitrogen is:

1. 
2. 
3. 
4. 

Q. Which of the following compound(s)cannot undergo self-aldol condensation in the presence of cold dilute alkali?

1. $C_6{H}_{5}CHO$
2. $C{H}_{3}C{H}_{2}CHO$
3. $HC\equiv CCHO$
4. $C{H}_2=CHCHO$

Q. What is an elimination reaction?

1. A reaction that removes an atom(s) from a molecule
2. A reaction that removes a double bond from a molecule
3. A reaction that removes all charges from a molecule
4. A reaction that completely removes a molecule (breaks it down into individual atoms)

Q.
Columns 1, 2 and 3 contain starting materials, reaction conditions, and type of reactions, respectively:
$\begin{array}{ccc}\text{Column 1}& \text{Column 2}& \text{Column 3}\\ \text{(I) Toluene}& \left(i\right)NaOH/B{r}_2& \text{(P) Condensation}\\ \text{(II) Acetophenone}& \left(ii\right)B{r}_2/hv& \text{(Q) Carboxylation}\\ \text{(III) Benzaldehyde}& \left(iii\right)(C{H}_{3}CO{)}_{2}O/C{H}_{3}COOK& \text{(R) Substitution}\\ \text{(IV) Phenol}& \left(iv\right)NaOH/C{O}_2& \text{(S) Haloform}\end{array}$The only CORRECT combination that gives two different carboxylic acids is:

1. (IV) (iii) (Q)
2. (III) (iii) (P)
3. (II) (iv) (R)
4. (I) (i) (S)

Q. why ortho methyl-aniline is more basic than ortho-ethyl-aniline??

Q. What is the unit of rate constant for first order reaction

Q. The total number of diprotic acids among the following is
$H_{3}P{O}_4{H}_{2}S{O}_4{H}_{3}P{O}_3{H}_2{S}_2{O}_7{H}_{3}B{O}_3{H}_{3}P{O}_2{H}_{2}Cr{O}_4{H}_{2}S{O}_3$

Q. Consider the following reaction, The possible product(s) is/are

1. 
2. 
3. 
4. 

Q. Which of the following will accept $H^{+}\text{from}N{H}_4^{+}$ ion?

1. 
2. 
3. 
4. 
   $C{H}_3-C{H}_2-N{H}_2$

Q. Which of the following statements is correct for the given alcohol?
$R-OH\stackrel{X^{\ominus }}{⟶}R-X+\stackrel{\ominus }{OH}$
X is halogen.

1. Reaction will not take place because $\stackrel{\ominus }{OH}$ is poor leaving group and $X^{\ominus }$ is weak base and $\stackrel{\ominus }{OH}$ is strong base.
2. Reaction will not take place because $\stackrel{\ominus }{OH}$ is poor leaving group $X^{\ominus }$ is strong base and $\stackrel{\ominus }{OH}$ is weak base.
3. Reaction will not take place because $\stackrel{\ominus }{OH}$ is good leaving group; $X^{\ominus }$ is strong base and $\stackrel{\ominus }{OH}$ is weak base
4. Reaction will not take place because $\stackrel{\ominus }{OH}$ is good leaving group; $X^{\ominus }$ is weak base and $\stackrel{\ominus }{OH}$ is strong base.

Q. Which of the following compound(s) cannot undergo aldol condensation ?

1. 
2. 
3. $HCHO$
4. 

Q. Chlorobenzene with HNO3 gives

Q. The correct decreasing order of acidic strength is:

1. $N{O}_{2}C{H}_{2}COOH>NCC{H}_{2}COOH>FC{H}_{2}COOH>ClC{H}_{2}COOH$
2. $FC{H}_{2}COOH>NCC{H}_{2}COOH>N{O}_{2}COOH>ClC{H}_{2}COOH$
3. $N{O}_{2}C{H}_{2}COOH>FC{H}_{2}COOH>NCC{H}_{2}COOH>ClC{H}_{2}COOH$
4. $NCC{H}_{2}COOH>N{O}_{2}C{H}_{2}COOH>FC{H}_{2}COOH>ClC{H}_{2}COOH$

Q.

A hydrocarbon on ozonolysis gives two moles of acetone. The type of hybridization that carbons undergoes in that hydrocarbon are

1. 2 - sp³ and 4 - sp²

2. 4 - sp³ and 4 - sp²

3. 2 - sp³ and 2 - sp²

4. 4 - sp³ and 2 - sp²

Q.

Benzaldehyde differs from acetaldehyde in this respect that the former does not react with

1. Tollens Reagent

2. NaHSO₃

3. HCN

4. Fehlings solution