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

Answer the following in one sentence :

Write one property of a buffer solution.

Select the most appropriate option.

Bond enthalpies of H–H, Cl–Cl, and H–Cl bonds are 434 kJ mol^–1, 242 kJ mol^–1, and 431 kJ mol^–1, respectively. Enthalpy of formation of HCl is _______.

Answer in brief.

Obtain the expression for work done in chemical reaction.

Answer the following in one sentence :

Classify the following buffers into different types :

CH₃COOH + CH₃COONa

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

Calculate the work done in the decomposition of 132 g of \[\ce{NH4NO3}\] at 100°C.

\[\ce{NH4NO3_{(s)} -> N2O_{(g)} + 2H2O_{(g)}}\]

State whether work is done on or by the system.

Answer the following question.

Calculate standard enthalpy of reaction,

Fe₂O_3(s) + 3CO_(g) → 2Fe_(s) + 3CO_2(g), from the following data.

Δ_f H°(Fe₂O₃) = - 824 kJ/mol,

Δ_f H°(CO) = - 110 kJ/mol,

Δ_f H°(CO₂) = - 393 kJ/mol

Answer the following question.

Calculate ΔU at 298 K for the reaction,

C₂H_4(g) + HCl_(g) → C₂H₅Cl_(g), ΔH = - 72.3 kJ

How much PV work is done?

Calculate the amount of work done in the

1) Oxidation of 1 mole HCl_(g) at 200 °C according to reaction.

4HCl_(g) + O_2(g) → 2Cl_2(g) + 2H₂O_(g)

2) Decomposition of one mole of NO at 300 °C for the reaction

2NO_(g) → N_2(g) + O_2(g)

Answer the following question.

When 6.0 g of O₂ reacts with CIF as per 

\[\ce{2ClF_{(g)} + O2_{(g)} -> Cl2O_{(g)} + OF2_{(g)}}\]

The enthalpy change is 38.55 kJ. What is the standard enthalpy of the reaction? (Δ_r H° = 205.6 kJ)

Calculate the standard enthalpy of formation of \[\ce{CH3OH_{(l)}}\] from the following data:

\[\ce{CH3OH_{(l)} + 3/2 O2_{(g)} -> CO2_{(g)} + 2H2O_{(l)} }\]; Δ_rH° = − 726 kJ mol^-1 

\[\ce{C_{(graphite)} + O2_{(g)} -> CO2_{(g)}}\]; Δ_cH° = −393 kJ mol⁻¹

\[\ce{H2_{(g)} + 1/2 O_{(g)} -> H2O_{(l)}}\]; Δ_fH° = −286 kJ mol⁻¹

Calculate the work done and comment on whether work is done on or by the system for the decomposition of 2 moles of NH₄NO₃ at 100 °C
NH₄NO_3(s) → N₂O_(g) + 2H₂O_(g)

Answer the following in brief.

Using the relationship ΔG° of cell reaction and the standard potential associated with it, how will you show that the electrical potential is an intensive property?

Derive the relationship between standard cell potential and equilibrium constant of cell reaction.

Equilibrium constant of the reaction, \[\ce{2Cu^{\oplus}_{(aq)} -> Cu^{2\oplus}_{(aq)} + Cu_{(s)}}\] is 1.2 × 10⁶. What is the standard potential of the cell in which the reaction takes place?

Ozone layer is depleted by ______.

Answer the following.

Name two gases which deplete ozone layer.

Answer the following.

Give one example showing reducing property of ozone.

How is dioxygen prepared in the laboratory from KClO₃?

What happens when lead sulfide reacts with ozone \[\ce{O3}\]?