Class 12 Chemistry - Chapter Biomolecules NCERT Solutions | What products would be formed when a nuc

What happens when D-glucose is treated with the following reagents? (i)HI (ii)Bromine water (iii)HNO₃

How do you explain the absence of aldehyde group in the pentaacetate of D-glucose?

Glucose or sucrose are soluble in water but cyclohexane or benzene (simple six membered ring compounds) are insoluble in water. Explain.

The melting points and solubility in water of amino acids are generally higher than that of the corresponding halo acids. Explain.

Define the following as related to proteins 

(i) Peptide linkage  (ii) Primary structure  (iii) Denaturation.

The two strands in DNA are not identical but are complementary. Explain.

Enumerate the reactions of D-glucose which cannot be explained by its open chain structure.

What are nucleic acids? Mention their two important functions.

Where does the water present in the egg go after boiling the egg?

How do you explain the amphoteric behaviour of amino acids?

For the reaction R → P, the concentration of a reactant changes from 0.03 M to 0.02 M in 25 minutes. Calculate the average rate of reaction using units of time both in minutes and seconds.

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)

(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?

Why are solids rigid?

Write any two characteristics of Chemisorption.

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

Which of the ores mentioned in Table 6.1 can be concentrated by magnetic separation method?

Why are pentahalides more covalent than trihalides?

Silver atom has completely filled d orbitals (4d10) in its ground state. How can you say that it is a transition element?

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

In the following pairs of halogen compounds, which compound undergoes faster S_N1 reaction?

Calculate the depression in the freezing point of water when 10 g of CH₃CH₂CHClCOOH is added to 250 g of water. K_a = 1.4 x 10^-3, K_f = 1.86 K kg mol^-1.

Which forces are involved in holding the drugs to the active site of enzymes ?

Is it true that under certain conditions, Mg can reduce SiO₂ and Si can reduce MgO? What are those conditions?

Give reason for the higher boiling point of ethanol in comparison to methoxymethane.

What are enzymes? Write in brief the mechanism of enzyme catalysis.

Predict which of the following will be coloured in aqueous solution?

Ti³⁺, V³⁺, Cu⁺, Sc³⁺, Mn²⁺, Fe³⁺ and Co²⁺.

Give reasons for each.

Classify the following as addition and condensation polymers: Terylene, Bakelite, Polyvinyl chloride, Polythene.

In the button cells widely used in watches and other devices the following reaction takes place:

Zn(s) + Ag₂O(s) + H₂O(l)  → Zn²⁺(aq) + 2Ag(s) + 2OH ^- (aq)

Determine and for the reaction.

Write down the number of 3d electrons in each of the following ions:

Ti²⁺, V²⁺, Cr³⁺, Mn²⁺, Fe²⁺, Fe³⁺, CO²⁺, Ni²⁺ and Cu²⁺.

Indicate how would you expect the five 3d orbitals to be occupied for these hydrated ions (octahedral).