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Question 1: Why is reproduction essential for organisms? Answer: Reproduction is a fundamental feature of all living organisms. It is a biological process through which living organisms produce offspring’s similar to them. Reproduction ensures the continuance of various species on the Earth. In the absence of reproduction, the species will not be able to exist …

NCERT Solutions for Class 12 Biology Chapter 1 – Reproduction in Organisms Read More »

Question 16.1: Sleeping pills are recommended by doctors to the patients suffering from sleeplessness but it is not advisable to take its doses without consultation with the doctor, Why? Answer: Most drugs when taken in doses higher than recommended may cause harmful effects and sometimes, may even lead to death. Hence, a doctor should always …

NCERT Solutions for Class 12 Chemistry Chapter 7 – Chemistry in Everyday Life Read More »

Question 15.1: What are polymers? Answer: Polymers are high molecular mass macromolecules, which consist of repeating structural units derived from monomers. Polymers have a high molecular mass (103 − 107 u). In a polymer, various monomer units are joined by strong covalent bonds. These polymers can be natural as well as synthetic. Polythene, rubber, and nylon 6, …

NCERT Solutions for Class 12 Chemistry Chapter 6 – Polymers Read More »

Question 14.1: Glucose or sucrose are soluble in water but cyclohexane or benzene (simple six membered ring compounds) are insoluble in water. Explain. Answer: A glucose molecule contains five −OH groups while a sucrose molecule contains eight −OH groups. Thus, glucose and sucrose undergo extensive H-bonding with water. Hence, these are soluble in water. But …

NCERT Solutions for Class 12 Chemistry Chapter 5 – Biomolecules Read More »

Question 13.1: Classify the following amines as primary, secondary or tertiary: (i) (ii) (iii) (C2H5)2CHNH2 (iv) (C2H5)2NH   Answer: Primary: (i) and (iii) Secondary: (iv) Tertiary: (ii) Question 13.2: (i) Write structures of different isomeric amines corresponding to the molecular formula, C4H11N (ii) Write IUPAC names of all the isomers. (iii) What type of isomerism is exhibited by different pairs of amines? Answer: (i), (ii) The …

NCERT Solutions for Class 12 Chemistry Chapter 4 – Amines Read More »

Question 12.1: Write the structures of the following compounds. (i) α-Methoxypropionaldehyde (ii) 3-Hydroxybutanal (iii) 2-Hydroxycyclopentane carbaldehyde (iv) 4-Oxopentanal (v) Di-sec-butyl ketone (vi) 4-Fluoroacetophenone Answer: (i) (ii) (iii) (iv) (v) (vi) Question 12.2: Write the structures of products of the following reactions; (i) (ii) (iii) (iv) Answer: (iv) Question 12.3: Arrange the following compounds in increasing order of their boiling points. CH3CHO, …

NCERT Solutions for Class 12 Chemistry Chapter 3 – Aldehydes, Ketones and Carboxylic Acids Read More »

Question 11.1: Classify the following as primary, secondary and tertiary alcohols: (i) (ii)  (iii)  (iv) (v) (vi) Answer: Primary alcohol → (i), (ii), (iii) Secondary alcohol → (iv), (v) Tertiary alcohol → (vi) Question 11.2: Identify allylic alcohols in the above examples. Answer: The alcohols given in (ii) and (vi) are allylic alcohols. Question 11.3: …

NCERT Solutions for Class 12 Chemistry Chapter 2 – Alcohols, Phenols and Ethers Read More »

Question 10.1: Write structures of the following compounds: (i) 2-Chloro-3-methylpentane (ii) 1-Chloro-4-ethylcyclohexane (iii) 4-tert. Butyl-3-iodoheptane (iv) 1,4-Dibromobut-2-ene (v) 1-Bromo-4-sec. butyl-2-methylbenzene Answer: (i) 2-Chloro-3-methyl pentane (ii) 1-Chloro-4-ethylcyclohexane (iii) 4- tert-Butyl-3-iodoheptane (iv) 1, 4-Dibromobut-2-ene (v) 1-Bromo-4-sec-butyl-2-methylbenzene Question 10.2: Why is sulphuric acid not used during the reaction of alcohols with KI? Answer: In the presence of sulphuric acid (H2SO4), KI produces HI …

NCERT Solutions for Class 12 Chemistry Chapter 1 – Haloalkanes and Haloarenes Read More »

Question 9.1: Write the formulas for the following coordination compounds: (i) Tetraamminediaquacobalt(III) chloride (ii) Potassium tetracyanonickelate(II) (iii) Tris(ethane−1,2−diamine) chromium(III) chloride (iv) Amminebromidochloridonitrito-N-platinate(II) (v) Dichloridobis(ethane−1,2−diamine)platinum(IV) nitrate (vi) Iron(III) hexacyanoferrate(II) Answer: (i)  (ii)  (iii)  (vi)  (v)  (vi)  Question 9.2: Write the IUPAC names of the following coordination compounds: (i) [Co(NH3)6]Cl3 (ii) [Co(NH3)5Cl]Cl2 (iii) K3[Fe(CN)6] (iv) K3[Fe(C2O4)3] (v) K2[PdCl4] (vi) [Pt(NH3)2Cl(NH2CH3)]Cl Answer: (i) Hexaamminecobalt(III) chloride (ii) Pentaamminechloridocobalt(III) chloride (iii) Potassium hexacyanoferrate(III) (iv) Potassium trioxalatoferrate(III) …

NCERT Solutions for Class 12 Chemistry Chapter 9 – Coordination Compounds Read More »

Question 8.1: Silver atom has completely filled d orbitals (4d10) in its ground state. How can you say that it is a transition element? Answer: Ag has a completely filled 4d orbital (4d10 5s1) in its ground state. Now, silver displays two oxidation states (+1 and +2). In the +1 oxidation state, an electron is removed from the s-orboital. However, …

NCERT Solutions for Class 12 Chemistry Chapter 8 – The d-and f-Block Elements Read More »