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

State Raoult’s law for the solutions of non-volatile solutes in volatile solvents.

Answer the following.

Using Raoult’s law, how will you show that ΔP = `"P"_1^0 "x"_2`? Where, x₂ is the mole fraction of solute in the solution and `"P"_1^0` vapour pressure of pure solvent.

Fish generally needs O₂ concentration in water at least 3.8 mg/L for survival. What partial pressure of O₂ above the water is needed for the survival of fish? Given the solubility of O₂ in water at 0 °C and 1 atm^-1 partial pressure is 2.2 × 10^-3 atm mol/L.

The vapour pressure of water at 20°C is 17 mm Hg. What is the vapour pressure of solution containing 2.8 g urea in 50 g of water?

A mixture of benzene and toluene contains 30% by mass of toluene. At 30°C, vapour pressure of pure toluene is 36.7 mm Hg and that of pure benzene is 118.2 mm Hg. Assuming that the two liquids form ideal solutions, calculate the total pressure and partial pressure of each constituent above the solution at 30°C.

Answer the following question.

Derive the expression for the maximum work.

Answer the following question.

Calculate the maximum work when 24 g of O₂ are expanded isothermally and reversibly from the pressure of 1.6 bar to 1 bar at 298 K.

Show that the time required for 99.9% completion of a first-order reaction is three times the time required for 90% completion.

Identify the chiral molecule from the following.

Identify chiral molecule/s from the following.

Anisole on heating with concentrated HI gives ______.

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Ethers react with cold and concentrated H₂SO₄ to form ________.

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Which one of the following compounds has the highest boiling point?

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Which of the following has the highest basic strength?

Answer in one sentence.

Write the order of the basicity of aliphatic alkylamine in the gaseous phase.

Answer in one sentence.

Why are primary aliphatic amines stronger bases than ammonia?

Answer in one sentence.

Arrange the following amines in increasing order of boiling points.

n-propylamine, ethylmethyl amine, trimethylamine.

Answer in one sentence.

Arrange the following amines in the increasing order of their pK_b values.

Aniline, Cyclohexylamine, 4-Nitroaniline

Explain the basic nature of amines with a suitable example.

Choose the correct option from the given alternatives.

Which of the following is made up of polyamides?