HSC Science (Electronics) 12th Standard Board Exam - Maharashtra State Board Important Questions for Chemistry

Which among the following reactions is an example of a zero order reaction?

a) `H_(2(g)) + I_(2(g)) -> 2HI_(g)`

b) `2H_2O_(2(l)) -> 2H_2O_(l) + O_(2(g))`

c) `C_12H_22O_(11(aq)) + H_2O_(l) -> C_6H_12O_(6(aq)) + C_6H_12O_(6(aq))`

d) `2NH_(3g)`   `N(2g) + 3H_(2(g))`

The rate constant of a first order reaction are 0.58 S^-1 at 313 K and 0.045 S^-1 at 293 K. What is the energy of activation for the reaction?

Calculate activation energy for a reaction of which rate constant becomes four times when temperature changes from 30 °C to 50 °C. (Given R = 8.314 JK⁻¹ mol⁻¹). 

How does calcination differ from roasting?

Write resonating structures of ozone.

The decomposition of N₂O_5(g) at 320K according to the following equation follows first order reaction:

`N_2O_(5(g))->2NO_(2(g))+1/2O_(2(g))`

The initial concentration of N₂O_5(g) is 1.24 x 10^-2 mol. L-1 and after 60 minutes 0.20x10^-2 molL^-1. Calculate the rate constant of the reaction at 320K.

Write cathode and anode reaction in a fuel cell.

The half-life period of zero order reaction A → product is given by

(a) `([A]_0)/k`

(b) `0.693/k`

(c) `[A]_0/(2k)`

(d) `(2[A]_0)/k`

How many faradays of electricity are required to produce 6 g of Mg from MgCl₂?

The half life period of a first order reaction is 6. 0 h . Calculate the rate constant

The molar conductivity of 0.05 M BaCl₂ solution at 25° C is 223Ω^-1 cm² mol^-1. What is its conductivity?

In a first-order reaction A → product, 80% of the given sample of compound decomposes in 40 min. What is the half-life period of the reaction? 

Choose the most correct option.

Which of the following is not correct?

Answer the following in one or two sentences.

Write any two functions of salt bridge.

Answer the following in one or two sentences.

What is standard cell potential for the reaction

\[\ce{3Ni_{(s)} + 2Al^{3+} (1M) → 3Ni^{2+} (1M) + 2Al(s)}\], if `E_"Ni"^circ` = –0.25 V and  `"E"_("Al")^circ` = –1.66 V?

Answer the following in one or two sentences.

Write Nernst equation. What part of it represents the correction factor for nonstandard state conditions?

Write electrode reactions for the electrolysis of aqueous NaCl.

Answer the following in brief.

Construct a galvanic cell from the electrodes Co³⁺ | Co and Mn²⁺/Mn. \[\ce{E{^{\circ}_{Co}}}\] = 1.82 V, \[\ce{E{^{\circ}_{Mn}}}\] = –1.18 V. Calculate \[\ce{E{^{\circ}_{cell}}}\]

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

It is impossible to measure the potential of a single electrode. Comment.