HSC Science (Electronics) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions

Write the reactions involved in the preparation of Teflon.

What type of magnetism is shown in the following alignment of magnetic moments?

On the basis of crystal field theory, write the electronic configuration for d⁴ ion if ∆₀ < P.

Define the following term:

Ferromagnetism

What are fuel cells?

How are the following conversions carried out?

Benzoic acid into metanitrobenzoic acid.

Define entropy.

State the superiority of crystal field theory over valence bond theory.

Write the molecular and structural formulae of Dithionous acid

Write chemical reaction to prepare the following polymer: Teflon

The standard enthalpy of combustion of formaldehyde Δ₀H⁰ = -571 kJ. How much heat will be evolved in the formation of 22 g of CO₂?

Pyrolusite ore is _______.

A 0.1 m solution of K₂SO₄ in water has a freezing point of –4.3°C. What is the value of van’t Hoff factor if K_f for water is 1.86 K kg mol^–1?

Answer the following in one or two sentences.

What is van’t Hoff factor?

Answer the following in one or two sentences.

How is van’t Hoff factor related to degree of ionization?

Answer the following in one or two sentences.

Which of the following solution will have higher freezing point depression and why?

i. 0.1 m NaCl

ii. 0.05 m Al₂(SO₄)₃

Answer the following in one or two sentences.

Which of the four colligative properties is most often used for molecular mass determination? Why?

Derive the relationship between the degree of dissociation of an electrolyte and van’t Hoff factor.

At 25 °C, a 0.1 molal solution of CH₃COOH is 1.35 % dissociated in an aqueous solution. Calculate the freezing point and osmotic pressure of the solution assuming molality and molarity to be identical.

A 0.15 m aqueous solution of KCl freezes at - 0.510 °C. Calculate i and osmotic pressure at 0 °C. Assume the volume of solution equal to that of water.