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

The rate constant for a first order reaction is 60 s⁻¹. How much time will it take to reduce the initial concentration of the reactant to its `1/16`th value?

For the decomposition of azoisopropane to hexane and nitrogen at 543 K, the following data are obtained.

Calculate the rate constant.

The time required for 10% completion of a first order reaction at 298 K is equal to that required for its 25% completion at 308 K. If the value of A is 4 × 10¹⁰ s⁻¹. Calculate k at 318 K and E_a.

Write any two characteristics of chemisorption.

Why are powdered substances more effective adsorbents than their crystalline forms?

Distinguish between the meaning of the terms adsorption and absorption. Give one example of.

What is the difference between physisorption and chemisorption?

Give reason why a finely divided substance is more effective as an adsorbent.

What are the factors which influence the adsorption of a gas on a solid?

Discuss the effect of temperature on the adsorption of gases on solids.

Which of the 3d series of the transition metals exhibits the largest number of oxidation states and why?

The `E_((M^(2+)//M))^Θ` value for copper is positive (+0.34 V). What is possibly the reason for this? (Hint: consider its high Δ_aH^Θ and low Δ_hydH^Θ)

How would you account for the irregular variation of ionization enthalpies (first and second) in the first series of the transition elements?

Why is the highest oxidation state of a metal exhibited in its oxide or fluoride only?

Which is a stronger reducing agent, Cr²⁺ or Fe²⁺ and why?

Calculate the ‘spin only’ magnetic moment of \[\ce{M^{2+}_{ (aq)}}\] ion (Z = 27).

Explain why Cu⁺ ion is not stable in aqueous solutions?

Why are Mn²⁺ compounds more stable than Fe²⁺ towards oxidation to their +3 state?

Explain briefly how +2 state becomes more and more stable in the first half of the first row transition elements with increasing atomic number?