List of top Questions asked in UP Board XII

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 \( \text{CaCl}_2 \).
Why do the conductivity of a solution decreases with dilution? Explain with reason.
In \( 2A \rightarrow \) Product, the reaction concentration of A remains 0.4 mol\(^{-1}\) from 0.5 mol\(^{-1}\) in 10 minutes.
Calculate the velocity of reaction for this period of time.
Differentiate between:
(x) Order of a reaction and molecularity
(y) Average and instantaneous velocity
Write IUPAC name of the following complexes: (x) \([Co(NH_3)_5Cl]Cl_2\) , (y) \(K_2[Ni(CN)_4]\)
Explain with reason:
(i) Cr^{2+} is a reducing agent while Mn^{3+} is an oxidising agent, while both have \(d^4\) configuration.}
Why metals show their maximum oxidation states in oxides and fluorides?
Transition metals generally form coloured compounds.
What do you understand by order of a reaction? Calculate the total order of those reactions which have velocity equations:
(i) Velocity \( = K[A]^{1/2}[B]^{3/2} \)
(ii) Velocity \( = K[A]^3[B]^{-1} \)
Differentiate between the following:
(i) Propanal and Propanone,
(ii) Phenol and Benzoic acid.
Give the name of two water-soluble vitamins and diseases due to deficiency of them.
Explain Raoult's Law. The vapour pressure of chloroform (\( \text{CHCl}_3 \)) and dichloromethane (\( \text{CH}_2\text{Cl}_2 \)) are 200 mm Hg and 4.5 mm Hg respectively at 298 K. Calculate the vapour pressure of the solution formed by mixing 51 g of \( \text{CHCl}_3 \) and 20 g of \( \text{CH}_2\text{Cl}_2 \) at 298 K.
The resistance of a column formed by a 0.10 mol L^{-1} concentrated solution is 6.5 × 10^3 ohm. Its diameter is 1 cm and length is 50 cm. Calculate its resistivity, conductivity and molar conductivity.
Explain the following reactions with suitable chemical equations:
(i) Wurtz reaction
(ii) Wurtz-Fittig reaction
Alcohols are more soluble in water in comparison to hydrocarbons of comparable molecular weight. Explain.
Why is there always a decreasing tendency of solubility of gases in liquid on rising temperature?
How many oxidation states are exhibited by lanthanides?
Show the geometrical isomers of \([Fe(NH_3)_2(CN)_4]\).