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

 Write the chemical equation for the preparation of 4 KMnO from 2. MnO Why does purple colour of acidified permanganate solution decolourise when it oxidises Fe^2- to Fe³⁺ ? 

 Write the ionic equation showing the oxidation of Fe(II) salt by acidified dichromate solutions. 

Answer the following question.
What is the basic structural difference between glucose and fructose?

Answer the following question.
When MnO₂ is fused with KOH in the presence of KNO₃ as an oxidizing agent, it gives a dark green compound (A). Compound (A) disproportionates in an acidic solution to give a purple compound (B).  An alkaline solution of compound (B) oxidizes KI to compound (C) whereas an acidified solution of compound (B) oxidizes KI to (D). Identify (A), (B), (C), and (D).

Using IUPAC norms, write the formula of potassium trioxalatochromate(III).

Write the structure of main compounds A and B in the following reaction:

\[\ce{CH3CH2CN->[CH3MgBRH/3O+]A->[LiAIH4]B}\]

Write the reaction involved when D-glucose is treated with the following reagent:

Br₂ water

Write the reactions involved when D-glucose is treated with the following reagent:
H₂N-OH

Write the reaction involved when D-glucose is treated with the following reagent:

(CH₃CO)₂O

Write the name of gas released when Cu is added to
dilute HNO₃

Write the name of gas released when Cu is added to
conc. HNO₃

Complete the following reaction:
\[\ce{(C6H5CH2)2Cd + 2CH3COCI}\]

Which is true for F-centers?

Which crystal system has axial angles equal to 90°?

Calculate the number of unit cells present in 1 g of gold which has a face-centered cubic lattice.

Which crystal system has a ≠ b ≠ c?

For a general electrochemical reaction of the type:

\[\ce{{a}A + {b}B ⇔ {c}C + {d}D}\]

Nernst equation can be written as:

For the first order reaction, half-life is equal to ____________.

Which process is usually applied for separating gangue from sulphide ores?

Zinc carbonate is precipitated from zinc sulphate solution by the addition of ___________.