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

Which halogen compound in the following pair will react faster in S_N2 reaction CH₃Br or CH₃I.

Which halogen compound in each of the following pairs will react faster in S_N2 reaction

(CH₃)₃ C – Cl or CH₃ – Cl

Write the type of magnetism observed when the magnetic moments are oppositely aligned and cancel out each other.

Write the type of magnetism observed when the magnetic moments are aligned in parallel and anti-parallel directions in unequal numbers.

What type of substances would make better permanent magnets, ferromagnetic or ferrimagnetic. Justify your answer.

Analysis shows that nickel oxide has the formula Ni_0.98O_1.00. What fractions of nickel exist as Ni²⁺ and Ni³⁺ ions?

Explain the following with suitable examples:

Paramagnetism

Explain the following with suitable examples:

Ferrimagnetism

Explain the following with suitable examples: 

Antiferromagnetism

The two strands in DNA are not identical but are complementary. Explain.

Give two examples to show the anomalous behaviour of fluorine.

Write two uses of ClO₂.

Why are halogens coloured?

Write the reactions of F₂ with water.

With what neutral molecule is ClO⁻ isoelectronic? Is that molecule a Lewis base?

Arrange the following in the order of property indicated for the given set:

HF, HCl, HBr, HI - increasing acid strength.

In terms of band theory, what is the difference between a conductor and an insulator?

In terms of band theory, what is the difference between a conductor and a semiconductor?

Sea is the greatest source of some halogens. Comment.

What happens when 

(i) PCl₅ is heated ? Write the reactions involved.