PREPWISER.
Practise online

Aldehydes & Ketones formula sheet

Every formula in the Aldehydes & Ketones chapter for JEE Main, with one line on when it applies. Topic 1 is open to everyone; sign in free to read all 17 and download the PDF.

Sign in to read all 17Download PDF

Read the first part free. Sign in free with Google to read the rest and download the PDF: 2 A4 pages.2 A4 pages, ready to print.

How we count: 7× asked means 7 past JEE Main questions in the PrepWiser bank needed that formula, and "last" is the latest year one appeared. ★ marks formulas asked 8 or more times.

Preparation of aldehydes and ketones

Ozonolysis and alkyne hydration
5× asked, last 2026
RX2C=CHRX′→(ii) Zn/HX2O(i) OX3RX2C=O+RX′CHORC≡CH→333 KHgX2+,  dil. HX2SOX4RCOCHX3\begin{aligned}&\ce{R2C=CHR^{\prime} ->[(i)\ \ce{O3}][(ii)\ \ce{Zn}/\ce{H2O}] R2C=O + R^{\prime}CHO}\\&\ce{RC#CH ->[\ce{Hg^{2+}},\ \text{dil. }\ce{H2SO4}][333\ K] RCOCH3}\end{aligned}
Zn stops RCHO going on to acid. Hydration is Markovnikov: only ethyne gives an aldehyde. Ring alkene: one dicarbonyl.
From acyl chlorides and nitriles
9× asked, last 2026
RCOCl→HX2,  Pd−BaSOX4RCHO (Rosenmund)RCN→(ii) HX3OX+(i) SnClX2/HClRCHO (Stephen)RCN→(ii) HX2O(i) DIBAL-HRCHORCN→(ii) HX3OX+(i) RX′MgXRCORX′\begin{aligned}&\ce{RCOCl ->[\ce{H2},\ \ce{Pd}-\ce{BaSO4}] RCHO}\ (\text{Rosenmund})\\&\ce{RCN ->[(i)\ \ce{SnCl2}/\ce{HCl}][(ii)\ \ce{H3O+}] RCHO}\ (\text{Stephen})\\&\ce{RCN ->[(i)\ \text{DIBAL-H}][(ii)\ \ce{H2O}] RCHO}\\&\ce{RCN ->[(i)\ \ce{R^{\prime}MgX}][(ii)\ \ce{H3O+}] RCOR^{\prime}}\end{aligned}
Poisoned Pd stops at RCHO. These keep the C count; RCN + R′MgX adds R′ (ketone, not amine).
Esters with DIBAL-H
RCOORX′→(ii) HX2O(i) DIBAL-HRCHO+RX′OH\ce{RCOOR^{\prime} ->[(i)\ \text{DIBAL-H}][(ii)\ \ce{H2O}] RCHO + R^{\prime}OH}
1 equiv., cold. LiAlHX4\ce{LiAlH4} overshoots to RCHX2OH\ce{RCH2OH}; from RCOOH go via SOClX2\ce{SOCl2} then Rosenmund.
Aromatic carbonyls
9× asked, last 2026
CX6HX5CHX3→(ii) HX3OX+(i) CrOX2ClX2CX6HX5CHO (Etard)CX6HX6→anhyd. AlClX3/CuClCO,  HClCX6HX5CHOCX6HX6→anhyd. AlClX3RCOClCX6HX5COR2 RCOCl+RX2′Cd→2 RCORX′+CdClX2\begin{aligned}&\ce{C6H5CH3 ->[(i)\ \ce{CrO2Cl2}][(ii)\ \ce{H3O+}] C6H5CHO}\ (\text{Etard})\\&\ce{C6H6 ->[\ce{CO},\ \ce{HCl}][\text{anhyd. }\ce{AlCl3}/\ce{CuCl}] C6H5CHO}\\&\ce{C6H6 ->[\ce{RCOCl}][\text{anhyd. }\ce{AlCl3}] C6H5COR}\\&\ce{2RCOCl + R^{\prime}2Cd -> 2RCOR^{\prime} + CdCl2}\end{aligned}
KMnOX4\ce{KMnO4} would give ArCOOH. Also CX6HX5CHClX2\ce{C6H5CHCl2} + water → CX6HX5CHO\ce{C6H5CHO}. –COR deactivates: one acyl only.

Practise Aldehydes & Ketones questions as you read. Free, and you can start without signing up.

Practise Aldehydes & Ketones

13 more formulas in 4 topics

Nucleophilic addition; Oxidation, reduction and the haloform reaction; α-Hydrogen and aldol condensation; and Cannizzaro reaction and tests. Read the first part free. Sign in free with Google to read the rest and download the PDF.

Sign in to read the restYou come straight back to this spot.Download the PDF

Nucleophilic addition

  • Reactivity6×
  • HCN, NaHSO₃, water5×
  • Acetals6×
  • Grignard addition4×
  • Ammonia derivatives6×

Oxidation, reduction and the haloform reaction

  • Tollens' and Fehling's8×
  • Haloform reaction12×
  • Reduction8×

α-Hydrogen and aldol condensation

  • Keto–enol tautomerism4×
  • Aldol condensation11×
  • Intramolecular aldol3×

Cannizzaro reaction and tests

  • Cannizzaro5×
  • Distinguishing tests7×

Practise Aldehydes & Ketones next

About 75 past JEE Main questions from this chapter, with instant answer checking and step-by-step solutions where available. Free, and you can start without signing up.

Practise Aldehydes & Ketones

Also free on PrepWiser

Spotted a mistake? Write to support@prepwiser.in and we will fix it in the next version.

Version 1, October 2026. Free to share for study, as it is. Please don't sell it or remove the PrepWiser name.

PractiseSign in to read all 17Download PDF
Free with Google, takes a few seconds2 pages, free