List of top Questions asked in UP Board XII

Which of the following gives a positive Fehling's solution test?
Best method of preparing primary amines from alkyl halides without changing the number of carbon atoms in the chain is
In a solution 30 mass percent of benzene is dissolved in carbon tetrachloride. Calculate mole fraction of benzene.
Explain Raoult's Law.
Example of gaseous solution is
Compound of which transition metal ion is colourless?
Gabriel-Pthalimide synthesis is given priority in the synthesis of primary amines.
Methyl amine gives precipitate of hydrated ferric oxide on reaction with ferric chloride in water.
Write the structure of the product for the reaction:
\[ \text{C}_6\text{H}_5\text{CH}_3 \xrightarrow{\text{CrO}_2\text{Cl}_2} \text{C}_6\text{H}_5\text{CHO} \]
Write the structure of the product for the reaction:
\[ \text{C}_6\text{H}_5\text{COOH} + \text{CH}_3\text{CH}_2\text{NH}_2 \xrightarrow{\text{H}^+} \text{C}_6\text{H}_5\text{CH}_2\text{NH}_2 \]
Write the following in order:
(i) Decreasing order of \( pK_b \) value: \( \text{C}_2\text{H}_5\text{NH}_2, \text{C}_6\text{H}_5\text{NHCH}_3, \text{C}_2\text{H}_5\text{NH}_2 \).
(ii) Decreasing order of basic strength: \( \text{C}_6\text{H}_5\text{NH}_2, \text{C}_6\text{H}_5\text{N(CH}_3\text{)}_2, \text{C}_6\text{H}_5\text{NH}_2 \).
(iii) Increasing order of basic strength: Aniline; p-nitroaniline; and paratoludine.
(iv) Solubility order in water: \( \text{C}_6\text{H}_5\text{NH}_2, (\text{C}_2\text{H}_5)_2\text{NH}, \text{C}_2\text{H}_5\text{NH}_2 \).
(v) Increasing order of boiling point: \( \text{C}_2\text{H}_5\text{OH}, \text{CH}_3\text{NH}_2, \text{C}_2\text{H}_5\text{NH}_2 \).
Aniline does not show Friedel-Crafts reaction.
What do you understand by these following terms? Give one example of each.
(i) Aldol (ii) Schiff's base (iii) Cannizaro's reaction (iv) Oxime (v) Acetal
Write the structure of the product for the reaction:
\[ \text{C}_6\text{H}_6 + \text{C}_2\text{H}_5\text{Cl} \xrightarrow{\text{Anhydrous AlCl}_3} \text{C}_6\text{H}_5\text{C}_2\text{H}_5 \]
Write the structure of the product for the reaction:
\[ \text{C}_6\text{H}_5\text{C}_2\text{H}_5 + \text{Cd} \xrightarrow{} 2\text{C}_2\text{H}_5\text{COCl} \]
Write the structure of the product for the reaction:
\[ \text{CH}_3\text{C} \equiv \text{CH} \xrightarrow{\text{Hg}^{2+}, \text{H}_2\text{SO}_4} \text{CH}_3\text{C}(\text{OH})\text{CH}_3 \]
Hydrogen atom of chloroform is acidic in nature.
Potassium cyanide gives alkyl cyanide on reaction with haloalkanes (R-X) while silver cyanide forms an isocyanide as main product.
How can these conversions be done? Give chemical equations only.
(i) Propan-2-ol from propene (ii) Benzyl alcohol from benzyl chloride (iii) Propan-1-ol from ethyl magnesium chloride (iv) 2-methyl propan-2-ol from methyl magnesium bromide (v) Picric acid from phenol
How will you synthesize the following? Give chemical equations only.
(i) 1-phenylethanol from a suitable alkene (ii) Cyclohexylmethanol with the help of alkyl halide by \( S_N2 \) reaction. (iii) Pentan-1-ol from a suitable alkyl halide.
Write the oxidation states, distribution of d-orbitals and coordination number of central metal of following complexes:
Write important structural and functional differences between DNA and RNA.
Write structural formula and IUPAC name of the following:
(i) sec-butyl chloride
(ii) isopentyl bromide
(iii) tert-butyl chloride
(iv) isobutyl chloride
(v) neopentyl chloride
Haloalkanes give nucleophilic substitution reactions while haloarenes give electrophilic substitution reactions.
Explain Kohlrausch Law. Limiting molar conductances (\( \lambda^0 \)) of \( \text{Ca}^{2+} \) and \( \text{Cl}^- \) ions in water at 298 K are 119.0 S cm\(^2\) mol\(^{-1}\) and 76.3 S cm\(^2\) mol\(^{-1}\) respectively. Calculate \( \lambda^0_m \) of \( \text{CaCl}_2 \).