34 public questions tagged with this topic.
Boiling points increase with the size and molecular mass of halogen atoms in halogenated hydrocarbons. This follows from NCERT principle where relation explains outcome clearly for students.
Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Some Basic Concepts, Structure of Atom, Periodicity and relevant Chemistry topic, Topic: Mole concept and periodic trends.
Decreasing external pressure reduces the energy needed for molecules to escape into the vapor phase, lowering the boiling point, as seen in high-altitude cooking. As per NCERT, applying relevant law/formula with correct units and sign convention leads to It decreases. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: NCBI Bookshelf, Ideal Gas Law: P1V1/T1 = P2V2/T2.
The Fahrenheit scale defines the freezing point of water as 32∘F and boiling point as 212∘F at standard pressure (Section 10.3). As per NCERT, applying relevant law/formula with correct units and sign convention leads to Fahrenheit. This satisfies dimensional consistency and physical conditions given, so option C is scientifically correct.
Ref: NCBI Bookshelf, Ideal Gas Law: P1V1/T1 = P2V2/T2.
At the boiling point of water under standard pressure, the Celsius scale reads 100∘C, while the Fahrenheit scale reads 212∘F, reflecting different interval sizes and zero points. As per NCERT, applying relevant law/formula with correct units and sign convention leads to Celsius is 100∘, Fahrenheit is 212∘. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: NCERT Class 11 Physics, Thermal Properties and Gravitation.
(CH₃)₂NH (secondary) has one N-H bond, while CH₃CH₂NH₂ (primary) has two, leading to less hydrogen bonding and a lower boiling point, as per the PDF.
Ref: NCERT Class 12 Chemistry > Chapter 13: Amines > Topic: Reaction with Nitrous Acid and Diazonium Salts - Part 1
For similar molecular weights, primary > secondary > tertiary due to decreasing hydrogen bonding, as per the PDF’s physical properties (e.g., CH₃CH₂NH₂ > (CH₃)₂NH > (CH₃)₃N).
Ref: NCERT Class 12 Chemistry > Chapter 13: Amines > Topic: Reaction with Nitrous Acid and Diazonium Salts - Part 1
Primary amines like CH₃CH₂CH₂NH₂ have higher boiling points due to extensive hydrogen bonding compared to secondary and tertiary amines, as per the PDF.
Ref: NCERT Class 12 Chemistry > Chapter 13: Amines > Topic: Reaction with Nitrous Acid and Diazonium Salts - Part 1
Primary amines like CH₃CH₂CH₂NH₂ have stronger hydrogen bonding than secondary or tertiary amines, leading to a higher boiling point, as per the PDF.
Ref: NCERT Class 12 Chemistry > Chapter 13: Amines > Topic: Reaction with Nitrous Acid and Diazonium Salts - Part 1
Ethylamine (CH₃CH₂NH₂) forms hydrogen bonds, unlike ethane (CH₃CH₃), which relies on weak van der Waals forces, as per the PDF’s physical properties.
Ref: NCERT Class 12 Chemistry > Chapter 13: Amines > Topic: Reaction with Nitrous Acid and Diazonium Salts - Part 1
Tertiary amines like (CH₃CH₂)₃N lack N-H bonds, so their boiling point depends on van der Waals forces, not hydrogen bonding, as per the PDF’s physical properties.
Ref: NCERT Class 12 Chemistry > Chapter 13: Amines > Topic: Reaction with Nitrous Acid and Diazonium Salts - Part 1
Boiling point depends on hydrogen bonding. (CH₃)₃N (tertiary amine) lacks hydrogen bonding, unlike CH₃NH₂ and CH₃CH₂NH₂ (primary amines), and has a lower molar mass than C₆H₅NH₂.
Ref: NCERT Class 12 Chemistry > Chapter 13: Amines > Topic: Chemical Reactions - Carbylamine Reaction and General Reactions
CH₃NH₂ (primary) forms hydrogen bonds, while (CH₃)₃N (tertiary) does not, leading to a higher boiling point for the former, as per the PDF.
Ref: NCERT Class 12 Chemistry > Chapter 13: Amines > Topic: Chemical Reactions - Carbylamine Reaction and General Reactions
