HSC Science (Computer Science) १२ वीं कक्षा - Maharashtra State Board Question Bank Solutions for Chemistry

Write the molecular formula and structural formula of BHA and BHT.

Identify the compounds 'A' and 'B' in the following equation:

How is Methoxyethane prepared from : Methyl iodide

Carbon atom in methyl carbocation contains how many pairs of electrons?

(a) 8

(b) 4

(c) 3

(d) 5

Bakelite is the polymer of:

(a) Benzaldchyde and phenol

(b) Acetaldehyde and phenol

(c) Formaldehyde and phenol

(d) Formaldehyde and benzyl alcohol

Give an example each of a molecular solid and an ionic solid.

Write the chemical equation involved in the following reaction:

Hoffmann-bromamide degradation reaction

Gas (A) is more soluble in water than Gas (B) at the same temperature. Which one of the two gases will have the higher value of KH (Henry’s constant) and why

The conductivity of 0.001 mol L-1 solution of CH₃COOH is 3.905× 10-5 S cm-1. Calculate its molar conductivity and degree of dissociation (α) Given λ°(H⁺)= 349.6 S cm² mol-1 and λ°(CH₃COO)= 40.9S cm²mol^-1.

Why do gases always tend to be less soluble in liquids as the temperature is raised?

A first order reaction takes 23.1 minutes for 50% completion. Calculate the time required for 75% completion of this reaction.

(log 2 = 0.301, log 3 = 0.4771, log 4 = 0.6021)

Define limiting molar conductivity.

Why conductivity of an electrolyte solution decreases with the decrease in concentration ?

A first order reaction takes 30 minutes for 50% completion. Calculate the time required for 90% completion of this reaction.

(log 2 = 0.3010)

The conductivity of 0.20 mol L⁻¹ solution of KCl is 2.48 × 10⁻² S cm⁻¹. Calculate its molar conductivity and degree of dissociation (α). Given λ⁰ (K⁺) = 73.5 S cm² mol⁻¹ and λ⁰ (C1⁻) = 76.5 S cm² mol⁻¹.

Why does the conductivity of a solution decrease with dilution?

Explain the principle of the method of electrolytic refining of metals. Give one example.

Define the following terms: Molar conductivity (⋀_m)

Explain ionic solids are hard and brittle.

Copper crystallises into a fcc lattice with edge length 3.61 × 10⁻⁸ cm. Show that the calculated density is in agreement with its measured value of 8.92 g cm⁻³.