PART - 1 CH - 3 Classification of Elements and Periodicity in Properties — Chemistry STD 11 Science — Question

Draw diagrams showing the formation of a double bond and a triple bond between carbon atoms in C₂H₄ and C₂H₂ molecules.

Balance the following equations in basic medium by ion-electron method and oxidation number methods and identify the oxidising agent and the reducing agent.

Cl₂O₇(g) + H₂O₂(aq) → ClO₂^-(aq) + O₂(g) + H⁺

The ionization constant of chloroacetic acid is 1.35 × 10^–3. What will be the pH of 0.1M acid and its 0.1M sodium salt solution?

The work function for caesium atom is 1.9 eV . Calculate (a) the threshold wavelength and (b) the threshold frequency of the radiation. If the caesium element is irradiated with a wavelength 500 nm , calculate the kinetic energy and the velocity of the rejected photoelectron.

Balance the following equations in basic medium by ion-electron method and oxidation number methods and identify the oxidising agent and the reducing agent.

N₂H₄(l) + ClO₃^-(aq) → NO(g) + Cl^-(g)

How do you count for the following observations?
Though alkaline potassium permanganate and acidic potassium permanganate both are used as oxidants, yet in the manufacture of benzoic acid from toluene we use alcoholic potassium permanganate as an oxidant. Why? Write a balanced redox equation for the reaction.

How do you account for the formation of ethane during chlorination of methane?

What is hybridization? Describe sp³, sp² and sp hybridization with examples.

Explain the general mechanism of electrophilic substitution of benzene.

What is Homologous series? Give its salient features.