Science (English Medium) Class 12 - CBSE Question Bank Solutions for Chemistry

Explain the solubility rule “like dissolves like” in terms of intermolecular forces that exist in solutions.

What is the significance of Henry’s Law constant K_H?

Explain the following phenomena with the help of Henry’s law.

Painful condition known as bends.

Match the items given in Column I with the type of solutions given in Column II.

Can `E_(Cell)^Θ` or `∆_rG^Θ` for cell reaction ever be equal to zero?

Under what condition is E_Cell = 0 or ∆_rG = 0?

Unlike dry cell, the mercury cell has a constant cell potential throughout its useful life. Why?

Write the Nernst equation for the cell reaction in the Daniel cell. How will the E_Cell be affected when concentration of Zn²⁺ ions is increased?

Assertion: Current stops flowing when E_Cell = 0.

Reason: Equilibrium of the cell reaction is attained.

Consider figure and answer the question to given below.

1. Redraw the diagram to show the direction of electron flow.
2. Is silver plate the anode or cathode?
3. What will happen if salt bridge is removed?
4. When will the cell stop functioning?
5. How will concentration of Zn²⁺ ions and Ag⁺ ions be affected when the cell functions?
6. How will the concentration of Zn²⁺ ions and Ag⁺ ions be affected after the cell becomes ‘dead’?

Extent of adsorption of adsorbate from solution phase increases with ______.

Which of the following phenomenon is applicable to the process shown in the figure?

Common impurities present in bauxite are:

(i) \[\ce{CuO}\]

(ii) \[\ce{ZnO}\]

(iii) \[\ce{Fe2O3}\]

(iv) \[\ce{SiO2}\] 

Which of the following elements does not show allotropy?

Which of the following is correct for P₄ molecule of white phosphorus?

(i) It has 6 lone pairs of electrons.

(ii) It has six P–P single bonds.

(iii) It has three P–P single bonds.

(iv) It has four lone pairs of electrons.

Which of the following statements are correct?

(i) All the three N – O bond lengths in \[\ce{HNO3}\] are equal.

(ii) All P – Cl bond lengths in \[\ce{PCl5}\] molecule in gaseous state are equal.

(iii) \[\ce{P4}\] molecule in white phosphorus have angular strain therefore white phosphorus is very reactive.

(iv) \[\ce{PCl}\] is ionic in solid state in which cation is tetrahedral and anion is octahedral.

Phosphorus has three allotropic forms — (i) white phosphorus (ii) red phosphorus and (iii) black phosphorus. Write the difference between white and red phosphorus on the basis of their structure and reactivity.

Gadolinium belongs to 4f series. It’s atomic number is 64. Which of the following is the correct electronic configuration of gadolinium?

General electronic configuration of actinoids is `(n-2)f^(1-14)(n - 1)d^(0-2)ns^2`.Which of the following actinoids have one electron in 6d orbital?

(i) U (Atomic no. 92)

(ii) Np (Atomic no.93)

(iii) Pu (Atomic no. 94)

(iv) Am (Atomic no. 95)

Which of the following lanthanoids show +2 oxidation state besides the characteristic oxidation state +3 of lanthanoids?

(i) \[\ce{Ce}\]

(ii) \[\ce{Eu}\]

(iii) \[\ce{Yb}\]

(iv) \[\ce{Ho}\]