Science (English Medium) Class 12 - CBSE Question Bank Solutions for Chemistry

Value of standard electrode potential for the oxidation of \[\ce{Cl-}\] ions is more positive than that of water, even then in the electrolysis of aqueous sodium chloride, why is \[\ce{Cl-}\] oxidised at anode instead of water?

Which reference electrode is used to measure the electrode potential of other electrodes?

Assertion: Cu is less reactive than hydrogen.

Reason: `E_((Cu^(2+))/(Cu))^Θ` is negative.

Consider the figure and answer the following question.

If cell ‘A’ has E_Cell = 0.5V and cell ‘B’ has E_Cell = 1.1V then what will be the reactions at anode and cathode?

At high pressure the following reaction is zero order.

\[\ce{2NH3(g) ->[1130 K][Platinum catalyst] N2(g) + 3H2(g)}\]

Which of the following options are correct for this reaction?

(i) Rate of reaction = Rate constant.

(ii) Rate of the reaction depends on concentration of ammonia.

(iii) Rate of decomposition of ammonia will remain constant until ammonia disappears completely.

(iv) Further increase in pressure will change the rate of reaction.

Which of the following graphs is correct for a zero order reaction?

Write the rate equation for the reaction `2A + B -> C` if the order of the reaction is zero.

Derive an expression to calculate time required for completion of zero order reaction.

For a zero order reaction will the molecularity be equal to zero? Explain.

Arrange the following diagrams in correct sequence of steps involved in the mechanism of catalysis, in accordance with modern adsorption theory.

                    (a)

             (b)

           (c)

               (d)

               (e)

In qualitative analysis when \[\ce{H2S}\] is passed through an aqueous solution of salt acidified with dil. \[\ce{HCl}\], a black precipitate is obtained. On boiling the precipitate with dil. \[\ce{HNO3}\], it forms a solution of blue colour. Addition of excess of aqueous solution of ammonia to this solution gives ______.

A brown ring is formed in the ring test for \[\ce{NO3^{-}}\] ion. It is due to the formation of ______.

In the preparation of HNO₃, we get NO gas by catalytic oxidation of ammonia. The moles of NO produced by the oxidation of two moles of NH₃ will be ______.

\[\ce{PCl5}\] reacts with finely divided silver on heating and a white silver salt is obtained, which dissolves on adding excess aqueous \[\ce{NH3}\] solution. Write the reactions involved to explain what happens.

The electronic configuration of \[\ce{Cu(II)}\] is 3d⁹ whereas that of \[\ce{Cu(I)}\] is 3d¹⁰. Which of the following is correct?

Which of the following complexes formed by \[\ce{Cu^2+}\] ions is most stable?

When 0.1 mol \[\ce{CoCl3 (NH3)5}\] is treated with excess of \[\ce{AgNO3}\], 0.2 mol of \[\ce{AgCl}\] are obtained. The conductivity of solution will correspond to ______.

When 1 mol \[\ce{CrCl3.6H2O}\] is treated with excess of \[\ce{AgNO3}\], 3 mol of \[\ce{AgCl}\] are obtained. The formula of the complex is ______.

The correct \[\ce{IUPAC}\] name of \[\ce{[Pt(NH3)2Cl2]}\] is ______.

The stabilisation of coordination compounds due to chelation is called the chelate effect. Which of the following is the most stable complex species?