List of top Questions asked in CBSE CLASS XII

Which of the following is most reactive towards nucleophilic substitution reaction?
The system that forms maximum boiling azeotrope is:
Maltose is made up of:
Which of the following is the strongest acid?
The equilibrium \( \text{Cr}_2\text{O}_7^{2-} \rightleftharpoons 2\text{CrO}_4^{2-} \):
The following initial rate data were obtained for the reaction: \[ 2\text{NO (g)} + \text{Br}_2 \text{(g)} \rightarrow 2 \text{NOBr (g)} \] initial rate data were obtained for the reaction
Write the chemical equation when:
(a) Butan-2-one is treated with Zn(Hg) and conc. HCl.
(b) Two molecules of benzaldehyde are treated with conc. NaOH.
Define colligative property. Which colligative property is preferred for the molar mass determination of macromolecules?
What happens when D-glucose is treated with the following reagents?
The compound which undergoes SN1 reaction most rapidly is:
For the reaction X + 2Y → P, the differential form equation of the rate law is:
1 molal aqueous solution of an electrolyte \( A_2B_3 \) is 60% ionized. Calculate the boiling point of the solution.
How does the size of blood cells change when placed in an aqueous solution containing more than 0.9% (mass/volume) sodium chloride?
What is peptide linkage?
Complete and balance the following chemical equations: 
Thermal decomposition of Potassium Permanganate
Explain the necessary conditions in which the trajectory of a charged particle is helical in a uniform magnetic field.
What are majority and minority charge carriers in an extrinsic semiconductor?
A battery of e.m.f. 12 V and internal resistance 0.5 \( \Omega \) is connected to a 9.5 \( \Omega \) resistor through a key. The ratio of potential difference between the two terminals of the battery, when the key is open to that when the key is closed, is:
Two identical point charges are placed at the two vertices A and B of an equilateral triangle of side \( l \). The magnitude of the electric field at the third vertex P is \( E \). If a hollow conducting sphere of radius \( l/4 \) is placed at P, the magnitude of the electric field at point P now becomes:
Consider the following reaction:
Identify A and B
Identify A and B from the given options:
Identify the tertiary amine from the following:
In a given graph of zero order reaction, the slope and intercept are:

zero order reaction
Write the chemical equations when: Two molecules of (CH3)3C–CHO are treated with conc. NaOH.
Alkyl halides give alcohol with aqueous KOH whereas in the presence of alcoholic KOH, alkenes are formed. Give reasons.
Grignard reagent should be prepared under anhydrous conditions. Give reasons.