HSC Science (Computer Science) १२ वीं कक्षा - Maharashtra State Board Important Questions

Derive the equation : W = - P_extAV

The process in which the value of ΔU = 0 is __

Give two uses of the Third law of thermodynamics.

Calculate the internal energy at 298K for the formation of one mole of ammonia, if the enthalpy change at constant pressure is – 42.0 kJ mol^-1.

(Given: R = 8.314 J K^-1 mol^-1)

Define Enthalpy of vaporization

A system absorbs 6 kJ of heat and does 1.5 kJ of work on its surroundings. The change in internal energy is __________.

Write the conditions for maximum work done by the system.

Calculate the work done in the following reaction at 50°C. State whether work is done on the system or by the system.
`"SO"_2("g") + 1/2"O"_(2("g")) rightarrow "SO"_(3("g"))`

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

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 features of a reversible process.

A substance which shows the highest entropy is ___________.

Choose the most correct answer:

Which of the Na following is a buffer solution?

Choose the most correct answer :

For pH > 7 the hydronium ion concentration would be _________.

Answer the following in brief :

What are acids and bases according to Arrhenius theory?

In NaOH solution [OH^–] is 2.87 × 10^–4. Calculate the pH of the solution.

Answer the following :

Explain the relation between ionic product and solubility product to predict whether a precipitate will form when two solutions are mixed?

For a reaction \[\ce{HCl_{(aq)} + H2O_{(l)} ⇌ H3O^+_{ (aq)} + Cl^-_{ (aq)}}\]

Which of the following is a conjugate acid-base pair?

The theory which explain amphoteric nature of water is ______.

The pK_b of weak base BOH [K_b(BOH) = 1 × 10^-5] will be ______.