Important Questions For Chemistry HSC Exam Feb 2021

                        

Q. Define terms: Fuel cell

Q. Write the chemical equations involved in the following reactions:(i) Hoffmann-bromamide degradation reaction

Q. The following data were obtained during the first order thermal decomposition of SO2Cl2 at a constant volume :

SO2Cl2 (g) → SO2 (g) + Cl2 (g)

Experiment       Time/s–          Total
                                  1          pressure/atm

        1                      0                   0.4

        2                      100               0.7

Calculate the rate constant.

(Given : log 4 = 0.6021, log 2 = 0.3010)


Q. Account for the following : Nitrogen does not form pentahalide.

Q.  What are ‘nucleic acids’?
Define complex lipids. Mention any ‘two’ functions of lipids.

Q. State Henry’s law.

Q. Define limiting molar conductivity

Q. What is the action of concentrated sulphuric acid on the following:
a. phosphorous pentachloride
b. copper
c. potassium chlorate?

Q. For a reaction A + B ⟶ P, the rate is given by
Rate = k [A] [B]2
How is the rate of reaction affected if the concentration of B is doubled?

Q. What is the action of the following reagents on ammonia:
a. Nessler’s reagent
b. Sodium metal

Q. For a reaction A + B ⟶ P, the rate is given by
Rate = k [A] [B]2
What is the overall order of reaction if A is present in large excess?

Q. [NiCl4]2− is paramagnetic, while [Ni(CO)4] is diamagnetic, though both are tetrahedral. Why? (Atomic number of Ni = 28)

Q. On the basis of crystal field theory, write the electronic configuration for d4 ion if ∆0 < P.

Q.Describe anomalous behaviour of fluorine with the other elements of group 17 with reference
to:
a. Hydrogen bonding
b. Oxidation state
c. Polyhalide ions

Q. Face centred cubic crystal lattice of copper has density of 9.966 g. cm–3. Calculate the volume
of the unit cell.
Given: Molar mass of copper is 63.5 g. mol–1 and Avogadro number NA is 6.022 × 1023 mol–1.

Q. Write a note on Hoffmann bromamide degradation.

Q. Write a note on ‘aldol condensation’.

Q. Explain the mechanism of alkaline hydrolysis of tert-butyl bromide with energy profile
diagram.
Define carbolic acid.
How carbolic acid is prepared from benzene sulphonic acid?

Q. State Faraday’s first law of electrolysis.
Write any ‘two’ uses of each of the following:
a. H2SO4 b. Chlorine
Distinguish between crystalline solids and amorphous solids.

Q.Define the following:
a. Leaching
b. Metallurgy
c. Anisotropy
Derive an expression for maximum work.

Q. How is phosphine prepared using the following reagents?
a. HCl
b. H2SO4
c. Caustic soda

Q. Define:
a. Molality               b. Osmotic pressure

Q. Define the term ‘enthalpy’.
What will happen to the internal energy if work is done by the system?

Q. Write the electronic configuration of the following elements:
a. Aluminium  (Z = 13)    b. Arsenic 
                                                (Z = 33)

Q. Calculate the percentage efficiency of packing in case of simple cubic cell.

Q. Write cathode and anode reaction in a fuel cell.

Q. How is nitroethane converted into:
 a. ethylamine,
 b. N-ethylhydroxylamine,
 c. acetic acid?

Q. Write names and chemical formulae of monomers used in preparing Buna-N.
What are soaps? How are they prepared?

Q. How is phenol prepared from cumene?

Q. Write a note on self oxidation-reduction reaction of aldehyde with suitable example.

Q. Explain basic nature of amines.

Q. What are antiseptics? Give any ‘two’ examples.

Q. An organic substance (M = 169 gram mol–1) is dissolved in 2000 cm3
 of water. Its osmotic
pressure at 12C was found to be 0.54 atm. If R = 0.0821 L atm K–1 mol–1, calculate the mass
of the solute.
Calculate the number of atoms in a unit cell of a metal crystallising in face centered cubic
structure.
Distinguish between isothermal process and adiabatic process.
Mention the names of various steps involved in the extraction of pure metals from their ores.

Q. State Henry’s Law.
How does solubility of a gas in water varies with temperature?

Q. Calculate the standard enthalpy of combustion of CH3COOH(l) from the following data:
fH (CO2) = – 393.3 kJ mol–1
fH (H2O) = – 285.8 kJ mol–1
fH (CH3COOH) = – 483.2 kJ mol–1

Q. Classify the following solids into different types:
a. Ammonium phosphate      b. Brass
c. S8 molecule                         d. Diamond

Q. What are carbohydrates? Write the reaction for the preparation of nylon-6.

Q. What are neutral oxides? Explain the nature of zinc oxide with the help of the reactions.
Define ‘molar conductivity’ and ‘zero order reaction’.

Q. Write mathematical equations of first law of thermodynamics for the following processes:
   a. Adiabatic process
   b. Isochoric process

Q. What are Ellingham diagrams? Write any two features of it.

Q. Explain with chemical reactions, why is zinc oxide amphoteric in nature?

Q. Write the structural formula and IUPAC names of all possible isomers of the compound with
molecular formula C3H8O.
Write ‘two’ uses of phenol.
What happens when glucose is treated with:
a. Bromine water
b. Dilute nitric acid
c. Hydrogen cyanide (HCN)

Q. Write the molecular formula and structural formula of BHA and BHT.
What are thermoplastic polymers?
Write a note on aldol condensation.

Q. What is a ‘soap’? How is it prepared?