Science (English Medium) इयत्ता १२ - CBSE Question Bank Solutions for Chemistry

What will happen during the electrolysis of aqueous solution of \[\ce{CuSO4}\] by using platinum electrodes?

(i) Copper will deposit at cathode.

(ii) Copper will deposit at anode.

(iii) Oxygen will be released at anode.

(iv) Copper will dissolve at anode.

What will happen during the electrolysis of aqueous solution of CuSO₄ in the presence of Cu electrodes?

(i) Copper will deposit at cathode.

(ii) Copper will dissolve at anode.

(iii) Oxygen will be released at anode.

(iv) Copper will deposit at anode.

Aqueous copper sulphate solution and aqueous silver nitrate solution are electrolysed by 1 ampere current for 10 minutes in separate electrolytic cells. Will the mass of copper and silver deposited on the cathode be same or different? Explain your answer.

Assertion: Electrolysis of NaCl solution gives chlorine at anode instead of O₂.

Reason: Formation of oxygen at anode requires overvoltage.

Consider the figure and answer the following question.

Cell ‘A’ has E_Cell = 2V and Cell ‘B’ has E_Cell = 1.1V which of the two cells ‘A’ or ‘B’ will act as an electrolytic cell. Which electrode reactions will occur in this cell?

In the extraction of chlorine by electrolysis of brine ______.

Which of the following reactions is an example of autoreduction?

Brine is electrolysed by using inert electrodes. The reaction at anode is ______.

At temperatures above 1073 K coke can be used to reduce \[\ce{FeO}\] to \[\ce{Fe}\]. How can you justify this reduction with Ellingham diagram?

Why are sulphide ores converted to oxide before reduction?

Strong reducing behaviour of \[\ce{H3PO2}\] is due to ______.

Which of the following statements are correct?

(i) \[\ce{CaF2 + H2SO4 -> CaSO4 + 2HF}\]

(ii) \[\ce{2HI + H2SO4 -> I2 + SO2 + 2H2O}\]

(iii) \[\ce{Cu + 2H2SO4 -> CuSO4 + SO2 + 2H2O}\]

(iv) \[\ce{Nacl + H2SO4 -> NaHSO4 + HCl}\]

Write a balanced chemical equation for the reaction showing catalytic oxidation of NH₃ by atmospheric oxygen.

Out of \[\ce{H2O}\] and \[\ce{H2S}\], which one has higher bond angle and why?

Which of the following options are correct for \[\ce{[Fe(CN)6]^{3-}}\] complex?

(i) d²sp³ hybridisation

(ii) sp³d² hybridisation

(iii) paramagnetic

(iv) diamagnetic

Magnetic moment of \[\ce{[MnCl4]^{2-}}\] is 5.92 BM. Explain giving reason.

Explain why \[\ce{[Fe(H2O)6]^{3+}}\] has magnetic moment value of 5.92 BM whereas \[\ce{[Fe(CN)6]^{3-}}\] – has a value of only 1.74 BM.

Why do compounds having similar geometry have different magnetic moment?

Assertion: \[\ce{[Fe(CN)6]^{3-}}\] ion shows magnetic moment corresponding to two unpaired electrons.

Reason: Because it has d²sp³ type hybridisation.

Which of the following compounds will give racemic mixture on nucleophilic substitution by \[\ce{OH-}\] ion?

(a) \[\begin{array}{cc}
\phantom{}\ce{CH3 - CH - Br}\\
\phantom{}|\\
\phantom{....}\ce{C2H5}\phantom{}
\end{array}\]

(b) \[\begin{array}{cc}
\phantom{..}\ce{Br}\\
\phantom{}|\\
\phantom{}\ce{CH3 - C - CH3}\\
\phantom{}|\\
\phantom{....}\ce{C2H5}\phantom{}
\end{array}\]

(c) \[\begin{array}{cc}
\phantom{....}\ce{CH3 - CH - CH2Br}\\
\phantom{}|\\
\phantom{....}\ce{C2H5}\phantom{}
\end{array}\]