WBJEE PYQs for Aldehydes, Ketones and Carboxylic Acids with Solutions: Practice WBJEE Previous Year Questions

1.

$C_4H_10 O { ->[{K_2Cr_2O_7}][{H_2SO_4}] }C_4H_5O { ->[{I_2/NaOH}][{\text{Warm}}] }CHI_3$ Here, N is

2.

An ideal solution of two liquids A and B is placed in a cylinder containing piston. Piston is pulled out isothermally so that the volume of the liquid decreases but that of vapours increases. Negligibly small amount of liquid was left and mole fraction of A in vapour is 0.4. If P⁰A = 0.4 atm and P⁰B at the experimental temperature, which of the following is the total pressure at which the liquid is almost evaporated?

• (A) 0.334 atm
  
• (B) 0.667 atm
  
• (C) 1 atm
  
• (D) 2 atm
  

3.

Amongst the following compounds, the one which would not form a white precipitate with ammonical silver nitrate solution is

• $HC = CH$
• $H_{3} C-C\equiv C-CH_{3}$
• $H_{3} C-C\equiv CH$
• $CH_{3} CH_{2} CH_{2} C\equiv CH$

4.

Distillation of acetone with concentrated sulphuric acid gives

• diacetone alcohol
• mesityl oxide
• mesitylene
• propene-$2$-ol

5.

The correct order of reactivity for the addition reaction of the following carbonyl compounds with ethylmagnesium iodide is

• I > III > II > IV
• IV > III > II > I
• I > II > IV > III
• III > II > I > IV

6.

Keto-enol tautomerism is not observed in

• $C_6H_5COC_6H_5$
• $C_6H_5COCH=CH_2$
• $C_6H_5COCH_2COCH_3$
• $CH_3COCH_2COCH_3$

7.

 
'G' in the above sequence of reaction is

• (CH₃)₂CHCOOCH₂CH₃
• CH₂CH₂CH₂COOCH₂CH₃
• CH₃CH₂COOCH₂CH₂CH₃
• CH₃CH₂COOCH(CH₃)₂

8.

Which of the following compounds has maximum volatility?

9.

Compound given below will produce effervescence when mixed with aqueous sodium bicarbonate solution

10.

The IUPAC name of CH₃CH=C-CHO-CH₂-CH₃ is:

• 3-Formyl-2-pentene
• 2-Ethylbut-2-enal
• 3-Ethylbut-3-enal
• 2-Ethylcrotonaldehyde

11.

Which of the following acids has the smallest dissociation constant?

• $CH _{3} CHFCOOH$
• $FCH_{2}CH_{2}COOH$
• $BrCH_{2}CH_{2}COOH$
• $CH_{3}CHBrCOOH$

12.

For making distinction between $2$-pentanone and $3$-pentanone the reagent to be employed is

• $K_{2} Cr_{2} O_{7} / H_{2} SO_{4}$
• $Zn-Hg / HCl$
• $SeO_{2}$
• Iodine/NaOH

13.

In $P{O}_4^{3-}$the formal charge on each oxygen atom and P − O bond order respectively are

• (A) − 0.75, 0.0
  
• (B) − 0.75, 1.0
  
• (C) − 0.75, 1.25
  
• (D) − 3, 1.25