default_background
✕

Find the best tutors and institutes for Class 12 Tuition

Find Best Class 12 Tuition

Please select a Category.

Please select a Locality.

No matching category found.

No matching Locality found.

Q8.1(ix):
What is meant by the following terms ? Give an example of the reaction in each case. (ix) 2,4-DNP-derivative

Solution :

1. Definition and Theoretical Foundation

A 2,4-DNP-derivative is a crystalline solid product formed via the nucleophilic addition-elimination reaction between a carbonyl compound (aldehyde or ketone) and 2,4-dinitrophenylhydrazine (2,4-DNP). These derivatives are highly valued in analytical chemistry due to their distinct melting points and characteristic orange-yellow to red coloration, which serves as a diagnostic test for the presence of the carbonyl functional group [Per the Mechanism of Nucleophilic Addition-Elimination].

2. Reaction Mechanism

The reaction proceeds as follows:

  1. Nucleophilic Attack: The lone pair on the terminal nitrogen ($NH_2$ group) of 2,4-dinitrophenylhydrazine attacks the electrophilic carbonyl carbon.
  2. Proton Transfer: A proton shift occurs from the nitrogen to the oxygen atom of the carbonyl group.
  3. Dehydration: Elimination of a water molecule ($H_2O$) results in the formation of a carbon-nitrogen double bond ($C=N$), known as a hydrazone [Based on the Dehydration mechanism of carbinolamines].

3. General Chemical Equation

$R_2C=O + C_6H_3(NO_2)_2NHNH_2 \rightarrow R_2C=NNHC_6H_3(NO_2)_2 + H_2O$

4. Illustrative Example: Acetone 2,4-DNP Derivative

Reacting propanone (acetone) with 2,4-DNP yields acetone-2,4-dinitrophenylhydrazone.

$CH_3COCH_3 + C_6H_3(NO_2)_2NHNH_2 \rightarrow (CH_3)_2C=NNHC_6H_3(NO_2)_2 + H_2O$

5. Visual Representation of the 2,4-DNP Molecule

NO₂ NO₂ NH-NH₂ 2,4-Dinitrophenylhydrazine Structure

6. Analytical Utility

Property Significance
Color Change Yellow/Orange/Red precipitate indicates $C=O$ presence.
Melting Point Used for identification of specific aldehydes or ketones via comparison with standard tables.

Final Solution: A 2,4-DNP-derivative is the stable, crystalline hydrazone formed by the reaction of an aldehyde or ketone with 2,4-dinitrophenylhydrazine, commonly used for the qualitative identification of carbonyl compounds through the elimination of water and formation of a substituted hydrazone.


More Questions from Class 12 Chemistry Aldehydes Exercises


CBSE Solutions for Class 12 Chemistry Aldehydes


Chapters in CBSE - Class 12 Chemistry


Top Tutors who teach Aldehydes

(12)
Top Tutor
locationImg G.T. Road, Ballabgarh
experience 7 yrs of Exp students 9 students
greenClock 389 hrs of classes completed
rsIcon 500 per hour
Online Classes Online Classes

I have done MTECH in ECE from YMCA university faridabad and BTECH from DIT university Dehradun. I Have been teaching BTECH ECE students for last 8 Years and Physics to students of class XI and XII for last 7 years. Physics has always excited me and its wonderful to be associated with physics & Besides, Teaching Physics imparts a sense of satisfaction to me. I have been giving home/online tutions to students of various schools in faridabad region. I also teach Maths to students of class IX an X. I have Published research papers based on Routing in Cognitive Networks in International Journals . Besides being an Educator I am Mentor/Counselor in the same College.

Meenakchi Sundareshvaran

Vivek sir is excellent in his way of teaching various concepts in physics ,he will clear all our doubts very patiently and in a way which u will understand it in an easy way

Skills: Mathematics , Physics
Also teaches: Class 11 Tuition

(15)
Top Tutor
locationImg Kharghar, Mumbai
experience 20 yrs of Exp students 1 student
greenClock 190 hrs of classes completed
rsIcon 500 per hour
Physics Tutor in Kharghar | Class 11 & 12 | Head Examiner | CENTA Rank 3 | M.Sc. B.Ed PGDCA
Online Classes Online Classes
regularClasses Tutor's home

I have over 22 years of teaching experience in reputed schools in India, with extensive experience in teaching Physics and Science at the Secondary and Senior Secondary levels. I have taught the CBSE/NCERT curriculum for Classes 9–12, with a strong focus on Physics for Classes 11 and 12 and board examination preparation. I served as the Head of the Science Department (HOD) for 7 years, providing academic leadership, curriculum planning, teacher coordination and mentoring. I have also worked as a Head Examiner for evaluation work, giving me valuable experience in assessment standards, question-paper analysis and examination evaluation. My students have consistently achieved proven and strong board examination results, reflecting my focus on conceptual clarity, systematic preparation, problem-solving and competency-based learning. My teaching methodology combines rigorous academic preparation with real-life applications and the effective use of digital teaching tools. I hold an M.Sc. in Physics and B.Ed., along with a PGDCA. I am a Microsoft Certified Educator and have completed professional certifications in online teaching and Design Thinking. In 2018, I secured 3rd rank in the CENTA Teaching Professionals’ Olympiad. Over the years, I have taught students with diverse learning abilities and developed a student-centred approach focused on conceptual understanding, confidence-building and excellent examination performance. I currently offer both online and offline individual and group classes.

Nirmala

Really happy with the Physics classes! Tuli Maam explains concepts clearly and makes even difficult topics easy to understand. I really appreciate that she focuses on making students understand the concepts rather than simply memorising formulas. Her guidance has helped build confidence and develop a much better understanding of Physics. Highly recommended!

Skills: Physics
Also teaches: Class 9 Tuition, Class 11 Tuition and more

Ajay S jadon Class 12 Tuition trainer in Kota
(82)
superTutorSuper Tutor
locationImg Talwandi Sector-B, Kota
experience 10 yrs of Exp students 15 students
greenClock 891 hrs of classes completed
rsIcon 1850 per hour
Author of DOOR TO IIT
Online Classes Online Classes
homeTutions Student's Home
regularClasses Tutor's home

My teaching exp.11 year in most reputed coaching in india. Mentor of jee top rank air-12 yatis agrawal, 19, 28 many more in top 100 in jee adavnced. Many of students got 100%tile in jee mains along with 100% marks in board exams. I also provide complete relevent study material like worksheet, practice sheet , dpps , assignment etc. Daily quizz based on assignment. Periodically test papers topic wise, minor and major as per shedule. I have helped thousands of students overcome their fear of maths.

Ayush Tripathy

Great Teaching Expertise High standard. Experienced Teacher with excellent knowledge. Thank you for reaching my son.

Skills: Mathematics , Physics and more

(20)
Top Tutor
locationImg Pandav Nagar, Ghaziabad
experience 9 yrs of Exp students 10 students
greenClock 22 hrs of classes completed
rsIcon 600 per hour
Mathematics is not about numbers, equation, computation, or algorithms it is about UNDERISTANDING.
regularClasses Tutor's home

I am an experienced, qualified teacher with over 9 years of experience in teaching Math across different boards including CBSE, ICSE and IGCSE and state board 9-12 and IIT JEE engineering entrance mathematics . I have worked in reputed institutes like Vibrant academy, Resonance in Kota and in Byjus and Modi School in Rajkot. Passionate about solving mathematical problems. And I have also been carrying out year of experience in Engineering Mathematics.

Prashant

Eti mam is a good teacher. She have a different way of teaching. I am glad to improved grades of my son.

Skills: Mathematics

(6)
Top Tutor
locationImg Jhunjhunu Bypass Rd, Sikar
experience 5 yrs of Exp students 4 students
greenClock 10 hrs of classes completed
rsIcon 150 per hour
Biology and SCIENCE Made Easy - Build strong basics for bright Results.|| 5 year experienced ||
Online Classes Online Classes
regularClasses Tutor's home

I have over 5 years of teaching experience in Class 12th Biology and chemistry as well, helping students build a strong foundation for both board exams and NEET preparation. My teaching method is concept-driven, where I explain each topic with clarity, real-life examples, and visual representation using a whiteboard setup, creating a true classroom-like environment. I cover the full Class 12 CBSE syllabus, including all core chapters such as: Reproduction (Human and Plants) Genetics and Evolution Biotechnology Human Health and Disease Ecology and Environment I focus on: NCERT line-by-line explanation Diagram-based questions Important previous year board and NEET questions Tips for writing high-scoring answers in board exams Clarifying complex concepts with simple analogies Many of my students have improved significantly in both their conceptual understanding and exam performance, and some have even scored above 90% in boards and qualified for NEET. My aim is to make Biology interesting and scoring — not just something to memorize, but something to truly understand.

Priyanka

Best tutor for NEET Physics prep! His tricks and concept clarity helped me solve questions faster in mock tests.

Skills: Biology , Chemistry

Other Subjects in CBSE - Class 12

Worksheet Icon

Download free CBSE - Class 12 Chemistry Aldehydes Exercises worksheets

Download Now

Find Best Class 12 Tuition ?

Find Now »