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

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.

Write the name of platinum complex used in the treatment of cancer.

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

Nitrous acid

Draw labelled diagram of H₂ – O₂ fuel cell.

Write two applications of fuel cells.

Explain Aldol condensation of ethanal.

Define and explain the term, enthalpy of reaction.

Isotonic solutions are the solutions having the same ______.

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

A solution containing 10 g glucose has osmotic pressure 3.84 atm. If 10 g more glucose is added to the same solution, what will be its osmotic pressure? (Temperature remains constant)

\[\ce{XeF6 + H2O ->[Partial][Hydrolysis] \underline{}\underline{}\underline{}\underline{} + \underline{}\underline{}\underline{}\underline{}}\]

\[\ce{XeF4 + H2O - \underline{}\underline{}\underline{}\underline{} + \underline{}\underline{}\underline{}\underline{}}\]

Which of the following reactions defines the enthalpy of formation?

Standard enthalpy of combustion of a substance is given. Then Write thermochemical equation.

Δ_cH⁰[C₂H₅OH(1)] = - 1409 kJ mol^-1

Standard enthalpy of combustion of a substance is given. Then Write thermochemical equation.

Δ_cH⁰[CH₃CHO(l)] = - 1166 kJ mol^-1

When acetaldehyde is treated with dilute NaOH, the following reaction is observed.

\[\begin{array}{cc}
\ce{2CH3 - CHO ->[dil.NaOH] CH3 - CH - CH2 - CHO}\\
\phantom{...............}|\\
\phantom{.................}\ce{OH}
\end{array}\]

1. What are the functional groups in the product?
2. Can another product be formed during the same reaction? (Deduce the answer by doing atomic audit of reactant and product).
3. Is this an addition reaction or condensation reaction?

Heat of combustion of methane is - 890 kJ/mol. On combustion of 12 gm of methane in excess of oxygen, ______ heat is evolved.