Write a chemical equation for each of the following. a) 2, 4 DNP test [1] b) Oxo process [1] c) Claisen condensation reaction [1] d) Wurtz Fittig reaction [1] e) Carboxylation reaction [1]

Chemical equations a) 2,4‑DNP test – Formation of a yellow‑orange precipitate (2,4‑dinitrophenylhydrazone) when a carbonyl compound reacts with 2,4‑dinitrophenylhydrazine (DNP). R2C=O + H2NNHC6H3(NO2)2 R2C=NNHC6H3(NO2)2 + H2O b) Oxo‑process – Hydroformylation of an alkene in the presence of a cobalt or rhodium catalyst to give an aldehyde. RCH=CH2 + CO + H2 [Co(CO)4] RCH2CH2CHO c) Claisen condensation – Condensation of two esters (or an ester with a ketone) in the presence of a strong base to give a β‑keto‑ester. CH3COOCH3 + CH3COOCH3 [NaOEt] CH3COCH2COOCH3 + EtOH (General form: RCOOR' + R'COOR' [Base] RCOCH2COOR' + R'OH ) d) Wurtz‑Fittig reaction – Coupling of an aryl halide with an alkyl halide using metallic sodium to afford a mixed aryl‑alkyl compound. C6H5Br + CH3Br + 2 Na C6H5CH3 + 2 NaBr e) Carboxylation reaction – Direct introduction of a carboxyl group into an organometallic reagent (e.g., Grignard) using carbon dioxide. R–MgX + CO2 [H2O] R–COOH + MgX(OH) These equations represent the essential transformations required for each named reaction in the NEB Class 12 Chemistry syllabus.

Write a chemical equation for each of the following. a) 2, 4 DNP test [1] b) Oxo process… – Chemistry NEB 2081 Solution

Chemical equations

a) 2,4‑DNP test – Formation of a yellow‑orange precipitate (2,4‑dinitrophenylhydrazone) when a carbonyl compound reacts with 2,4‑dinitrophenylhydrazine (DNP).

$R X_{2} C = O + H X_{2} NNHC X_{6} H X_{3} (NO X_{2}) X_{2} R X_{2} C = NNHC X_{6} H X_{3} (NO X_{2}) X_{2} + H X_{2} O$

b) Oxo‑process – Hydroformylation of an alkene in the presence of a cobalt or rhodium catalyst to give an aldehyde.

$RCH = CH X_{2} + CO + H X_{2} Co (CO) X_{4} RCH X_{2} CH X_{2} CHO$

c) Claisen condensation – Condensation of two esters (or an ester with a ketone) in the presence of a strong base to give a β‑keto‑ester.

$CH X_{3} COOCH X_{3} + CH X_{3} COOCH X_{3} NaOEt CH X_{3} COCH X_{2} COOCH X_{3} + EtOH$

(General form: $RCOOR X^{'} + R X^{'} COOR X^{'} Base RCOCH X_{2} COOR X^{'} + R X^{'} OH$ )

d) Wurtz‑Fittig reaction – Coupling of an aryl halide with an alkyl halide using metallic sodium to afford a mixed aryl‑alkyl compound.

$C X_{6} H X_{5} Br + CH X_{3} Br + 2 Na C X_{6} H X_{5} CH X_{3} + 2 NaBr$

e) Carboxylation reaction – Direct introduction of a carboxyl group into an organometallic reagent (e.g., Grignard) using carbon dioxide.

C₆H₅MgBr+CO₂Dry ether, then H₃O⁺C₆H₅COOMgBr+H₂O

Carboxylation of a Grignard reagent with CO₂ to form benzoic acid

$R - MgX + CO X_{2} H X_{2} O R - COOH + MgX (OH)$

These equations represent the essential transformations required for each named reaction in the NEB Class 12 Chemistry syllabus.

Write a chemical equation for each of the following. a) 2, 4 DNP test [1] b) Oxo process [1] c) Claisen condensation reaction [1] d) Wurtz Fittig reaction [1] e) Carboxylation reaction [1]

Chemical equations

Discussion

More Chemistry questions