PUC Science 2nd PUC Class 12 - Karnataka Board PUC Question Bank Solutions

What is the effect of temperature on chemisorption ?

Write the structure of p-methylbenzaldehyde.

How will you distinguish between the following pair of terms?

Crystal lattice and unit cell

Account for the following:

Zn is not considered as a transition element.

Account for the following:

E° value for the Mn³⁺/Mn²⁺ couple is much more positive than that for Cr³⁺/Cr²⁺.

Out of Mn³⁺ and Cr³⁺, which is more paramagnetic and why ?

(Atomic nos. : Mn = 25, Cr = 24)

Why is adsorption always exothermic?

Why does NO₂ dimerise?

Write the structure of 4-chloropentan-2-one.

Give the significance of a ‘lattice point’.

Name the parameters that characterize a unit cell.

Which of the following lattices has the highest packing efficiency (i) simple cubic (ii) body-centred cubic and (iii) hexagonal close-packed lattice?

What is meant by the term ‘coordination number’?

How would you determine the standard electrode potential of the system \[\ce{Mg^{2+} | Mg}\]?

Consult the table of standard electrode potentials and suggest three substances that can oxidise ferrous ions under suitable conditions.

Calculate the standard cell potential of a galvanic cell in which the following reaction takes place:

\[\ce{2Cr_{(s)} + 3Cd{^{2+}_{(aq)}} -> 2Cr{^{3+}_{(aq)}} + 3Cd}\]

Calculate the Δ_rG° and equilibrium constant of the reaction.

A first order reaction has a rate constant 1.15 × 10⁻³ s⁻¹. How long will 5 g of this reactant take to reduce to 3 g?

Time required to decompose SO₂Cl₂ to half of its initial amount is 60 minutes. If the decomposition is a first order reaction, calculate the rate constant of the reaction.

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

\[\ce{SO2Cl2_{(g)} -> SO2_{(g)} + Cl2_{(g)}}\]

In a pseudo first order hydrolysis of ester in water, the following results were obtained:

Calculate the average rate of reaction between the time interval 30 to 60 seconds.