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

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

Arrange the following compounds in increasing order of rate of reaction towards nucleophilic substitution.

(a)
(b)
(c)

Arrange the following compounds in increasing order of rate of reaction towards nucleophilic substitution.

(a)
(b)
(c)

Arrange the following compounds in increasing order of rate of reaction towards nucleophilic substitution.

(a)
(b)
(c)

Arrange the following compounds in increasing order of rate of reaction towards nucleophilic substitution.

(a)
(b)
(c)

Haloarenes are less reactive than haloalkanes and haloalkenes. Explain.

Allyl chloride is hydrolysed more readily than n-propyl chloride. Why?

What is Hinsberg's reagent?