practice question for board exam

• Q:-
  Give simple chemical tests to distinguish between the following pairs of compounds.
  (i) Propanal and Propanone
  (ii) Acetophenone and Benzophenone
  (iii) Phenol and Benzoic acid
  (iv) Benzoic acid and Ethyl benzoate
  (v) Pentan-2-one and Pentan-3-one
  (vi) Benzaldehyde and Acetophenone
  (vii) Ethanal and Propanal
• Q:-
  How the following conversions can be carried out?
  (i) Propene to propan-1-ol
  (ii) Ethanol to but-1-yne
  (iii) 1-Bromopropane to 2-bromopropane
  (iv) Toluene to benzyl alcohol
  (v) Benzene to 4-bromonitrobenzene
  (vi) Benzyl alcohol to 2-phenylethanoic acid
  (vii) Ethanol to propanenitrile
  (viii) Aniline to chlorobenzene
  (ix) 2-Chlorobutane to 3, 4-dimethylhexane
  (x) 2-Methyl-1-propene to 2-chloro-2-methylpropane
  (xi) Ethyl chloride to propanoic acid
  (xii) But-1-ene to n-butyliodide
  (xiii) 2-Chloropropane to 1-propanol
  (xiv) Isopropyl alcohol to iodoform
  (xv) Chlorobenzene to p-nitrophenol
  (xvi) 2-Bromopropane to 1-bromopropane
  (xvii) Chloroethane to butane
  (xviii) Benzene to diphenyl
  (xix) tert-Butyl bromide to isobutyl bromide
  (xx) Aniline to phenylisocyanide
• Q:-Henry's law constant for CO₂ in water is 1.67 x 10⁸Pa at 298 K. Calculate the quantity of CO₂in 500 mL of soda water when packed under 2.5 atm CO₂ pressure at 298 K.
  ">
  Henry's law constant for CO₂ in water is 1.67 x 10⁸Pa at 298 K. Calculate the quantity of CO₂in 500 mL of soda water when packed under 2.5 atm CO₂ pressure at 298 K.
• Q:-
  Predict the products of electrolysis in each of the following:
  (i) An aqueous solution of AgNO₃ with silver electrodes.
  (ii) An aqueous solution of AgNO₃with platinum electrodes.
  (iii) A dilute solution of H₂SO₄with platinum electrodes.
  (iv) An aqueous solution of CuCl₂ with platinum electrodes.
• Q:-
  Write the names and structures of the monomers of the following polymers:
  (i) Buna-S  (ii) Buna-N
  (iii) Dacron  (iv) Neoprene
• Q:-
  Depict the galvanic cell in which the reaction Zn(s) + 2Ag⁺(aq) → Zn²⁺(aq) + 2Ag(s) takes place.
  Further show:
  (i) Which of the electrode is negatively charged?
  (ii) The carriers of the current in the cell.
  (iii) Individual reaction at each electrode.
• Q:-H₂S, a toxic gas with rotten egg like smell, is used for the qualitative analysis. If the solubility of H₂S in water at STP is 0.195 m, calculate Henry's law constant.
  ">
  H₂S, a toxic gas with rotten egg like smell, is used for the qualitative analysis. If the solubility of H₂S in water at STP is 0.195 m, calculate Henry's law constant.
• Q:-
  What is a biodegradable polymer? Give an example of a biodegradable aliphatic polyester.
• Q:-
  Calculate the mole fraction of benzene in solution containing 30% by mass in carbon tetrachloride.
• Q:-The vapour pressure of pure liquids A and B are 450 and 700 mm Hg respectively, at 350 K. Find out the composition of the liquid mixture if total vapour pressure is 600 mm Hg. Also find the composition of the vapour phase.
  ">
  The vapour pressure of pure liquids A and B are 450 and 700 mm Hg respectively, at 350 K. Find out the composition of the liquid mixture if total vapour pressure is 600 mm Hg. Also find the composition of the vapour phase.

RECENTLY VIEWED QUESTIONS OF CLASS 12TH CHEMISTRY

• Q:-The partial pressure of ethane over a solution containing 6.56 x 10^-3 g of ethane is 1 bar. If the solution contains 5.00 x 10^-2 g of ethane, then what shall be the partial pressure of the gas?
  ">
  The partial pressure of ethane over a solution containing 6.56 x 10^-3 g of ethane is 1 bar. If the solution contains 5.00 x 10^-2 g of ethane, then what shall be the partial pressure of the gas?
• Q:-
  What role does adsorption play in heterogeneous catalysis?
• Q:-
  Why is sulphuric acid not used during the reaction of alcohols with KI?
• Q:-
  Give simple chemical tests to distinguish between the following pairs of compounds.
  (i) Propanal and Propanone
  (ii) Acetophenone and Benzophenone
  (iii) Phenol and Benzoic acid
  (iv) Benzoic acid and Ethyl benzoate
  (v) Pentan-2-one and Pentan-3-one
  (vi) Benzaldehyde and Acetophenone
  (vii) Ethanal and Propanal
• Q:-Knowing the electron gain enthalpy values for O → O^- and O → O^2- as -141 and 702 kJ mol^-1 respectively, how can you account for the formation of a large number of oxides having O^2- species and not O^-? (Hint: Consider lattice energy factor in the formation of compounds).
  ">
  Knowing the electron gain enthalpy values for O → O^- and O → O^2- as -141 and 702 kJ mol^-1 respectively, how can you account for the formation of a large number of oxides having O^2- species and not O^-? (Hint: Consider lattice energy factor in the formation of compounds).
• Q:-Henry's law constant for CO₂ in water is 1.67 x 10⁸Pa at 298 K. Calculate the quantity of CO₂in 500 mL of soda water when packed under 2.5 atm CO₂ pressure at 298 K.
  ">
  Henry's law constant for CO₂ in water is 1.67 x 10⁸Pa at 298 K. Calculate the quantity of CO₂in 500 mL of soda water when packed under 2.5 atm CO₂ pressure at 298 K.
• Q:-
  Why is the highest oxidation state of a metal exhibited in its oxide or fluoride only?
• Q:-
  What are the main constituents of dettol?
• Q:-
  Calculate the standard cell potentials of galvanic cells in which the following reactions take place:
  (i) 2Cr(s) + 3Cd²⁺(aq) → 2Cr³⁺(aq) + 3Cd
  (ii) Fe²⁺(aq) + Ag+(aq) → Fe³⁺(aq) + Ag(s)
  Calculate the ΔrG^ø¸ and equilibrium constant of the reactions.
• Q:-
  How would you determine the standard electrode potential of the system Mg²⁺ | Mg?