HSC Science (Computer Science) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions for Chemistry

Define the Bond enthalpy.

Calculate the standard enthalpy of the reaction.

\[\ce{2Fe_{(s)} + \frac{3}{2} O_{2(g)} -> Fe2O_{3(s)}}\]

Given:

Define the Enthalpy of ionisation.

Write an application of Hess’s law.

Does the following reaction represent a thermochemical equation?

\[\ce{CH_{4(g)} + 2O_{2(g)} -> CO_{2(g)} + 2H2O_{(g)}}\], ∆_fH° = –900 kJ mol^–1

Classify the following into intensive and extensive properties.

Pressure, volume, mass, temperature.

Write any three advantages of nanoparticles and nanotechnology.

Explain any three characteristic features of nanoparticles.

State disadvantages of nanoparticles and nanotechnology.

Write the name of biodegradable polyamide copolymer.

Derive an expression to calculate molar mass of non-volatile solute by osmotic pressure measurement.

Identify A and B from the following reaction:

\[\begin{array}{cc}
\ce{CH3}\phantom{.................}\\
|\phantom{....................}\\
\phantom{}\ce{2CH3 - C = O ->[Ba(OH)2] A ->[Δ] B + H2O}
\end{array}\]

Write two disadvantages of nanotechnology.

Calculate the standard enthalpy of formation of CH₃OH_(l) from the following data:

1. \[\ce{CH3OH_{(l)} + 3/2 O2_{(g)} -> CO2_{(g)} + 2H2O_{(l)}ΔH^° = - 726 kJ mol^{-1}}\]
2. \[\ce{C_{(s)} + O2_{(g)} → CO2_{(g)}Δ_cH^° = – 393 kJ mol^{-1}}\]
3. \[\ce{H2_{(g)} + 1/2 O2_{(g)} -> H2O_{(l)}Δ_fH^° = - 286 kJ mol^{-1}}\]

Which cells is used as a source of power in flashlights?

Calculate the standard enthalpy of:

\[\ce{N2H_{4(g)} + H_{2(g)} -> 2NH_{3(g)}}\]

If ΔH⁰(N – H) = 389 kJ mol^–1, ΔH⁰(H – H) = 435 kJ mol^–1, ΔH⁰(N – N) = 159 kJ mol^–1.

Write the reaction of conc. H₂SO₄ with sugar. What is the role of H₂SO₄ in this reaction?

Write electrode reactions and overall cell reaction when Leclanche's dry cell generates electricity.

What is the action of the following reagent on ethyl amine?

Nitrous acid

Draw labelled diagram of H₂ – O₂ fuel cell.