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

Name the type of cell which was used in Apollo space programme for providing electrical power.

State second law of electrolysis

Obtain the relationship between ΔH and ΔU for gas phase reactions.

The work done in vacuum when 300 m mole of an ideal gas expands until its volume is increased by 2.3 dm³ at 1 bar pressure is ______ mole.

The enthalpy change of the following reaction:

\[\ce{CH_{4(g)} + Cl_{2(g)} -> CH3Cl_{(g)} + HCl_{(g)}ΔH^0 = –104 kJ}\]

Calculate C – Cl bond enthalpy. The bond enthalpies are:

Derive the expression for work done in chemical reaction. Write the relationship between ∆H and ∆U for an isochoric process.

Define the extensive properties.

Write an application of Hess’s law.

Calculate the standard enthalpy of the reaction, \[\ce{SiO2_{(s)} + 3C_{(graphite)} -> SiC_{(s)} + 2CO_{(g)}}\] from the following reactions:

1. \[\ce{Si_{(s)} + O2_{(g)} -> SiO2_{(s)}}\], Δ_rH⁰ = −911 kJ
2. \[\ce{2C_{(graphite)} + O2_{(g)} -> 2CO_{(g)}}\], Δ_rH⁰ = −221 kJ
3. \[\ce{Si_{(s)} + C_{(graphite)} -> SiC_{(s)}}\], Δ_rH⁰ = −65.3 kJ

What happens if external potential applied becomes greater than E°cell of electrochemical cell?

The rate constant of a first order reaction increases from 2 × 10⁻² to 4 × 10⁻² when the temperature changes from 300 K to 310 K. Calculate the energy of activation (E_a).

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

Write applications of electrochemical series.

Give SI unit of resistivity.

Write an equation that shows the relationship between molar conductivity and degree of dissociation of weak electrolyte.

Write applications of Kohlrausch’s Law.

What is the mass of copper metal produced at cathode during the passage of 2.03 A current through the CuSO₄ solution for 1 hour. Molar mass of Cu = 63.5 g mol^–1.

Calculate molar conductivities at zero concentration for CaCl₂ and NaCl.

Given: molar ionic conductivities of Ca²⁺, Cl^–, Na⁺ ions are respectively, 104, 76.4, 50.1 Ω–1 cm^–2 mol^–1

Write two applications of fuel cells.

Draw a neat labelled diagram of a lead accumulator.

Define electrochemical series.