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

5 moles of helium expand isothermally and reversibly from a pressure 40 × 10^-5  N m^-2 to 4 × 10^-5 N m^-2  at 300 K. Calculate the work done, change in internal energy and heat absorbed during the expansion. (R = 8.314 J K^-1  mol^-1).

Write any ‘four points’ of difference between fluorine and other halogens.

What is the action of following reagents on glucose?
1. Bromine water
2. Hydroxylamine

Draw the structures of veronal and thymine. 

The ligand triethylenetetramine is _______.

The functional group present in triacylglycerol is _______.

Answer the following in brief.

Calculate the number of atoms in fcc unit cell.

Obtain the relationship between the density of a substance and the edge length of the unit cell.

An element with molar mass 27 g/mol forms a cubic unit cell with edge length of 405 p.m. If the density of the element is 2.7 g/cm³, what is the nature of the cubic unit cell?

Choose the most correct option.

The vapour pressure of a solution containing 2 moles of a solute in 2 moles of water (vapour pressure of pure water = 24 mm Hg) is ______.

Choose the most correct option.

Vapour pressure of a solution is _______.

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.