List of top Chemistry Questions asked in CBSE CLASS XII

Match the type of cell given in Column I with their use given in Column II.
Column I Column II
i. Lead storage celld. Inverter
ii. Mercury cellb. Apollo Space Programme
iii. Dry cellc. Wrist watch 
iv. Fuel cella. Wall clock
In which of the following groups are both ions coloured in aqueous solution?
Which of the following aqueous solutions will have the highest freezing point?
The treatment of ethyl bromide with alcoholic silver nitrite gives:
A plot between concentration of reactant [R] and time ‘t’ is shown below. Which of the given order of reaction is indicated by the graph?
concentration of reactant [R] and time
Which of the following aldehydes will undergo Cannizzaro reaction?
CH3CH2OH can be converted to CH3CHO by :
The IUPAC name for CH3 - CH2 - N(CH3) - CH2 - CH2 - CH3 is :
Which of the following molecules is chiral in nature?

The following data were obtained during the first order thermal decomposition of \( \text{N}_2\text{O}_5(g) \) at constant volume:

Assertion (A): Cu cannot liberate \( H_2 \) on reaction with dilute mineral acids. 
Reason (R): Cu has positive electrode potential.

Assertion (A): Cu cannot liberate \( H_2 \) on reaction with dilute mineral acids. Reason (R): Cu has positive electrode potential.
Out of KMnO$_4$ and K$_2$MnO$_4$, which one is paramagnetic and why?
How do you prepare potassium manganate from pyrolusite ore?
Why is the ability of oxygen greater than fluorine to stabilise higher oxidation states of transition metals?
Assertion (A): Vitamin C cannot be stored in our body.
Reason (R): Vitamin C is water soluble and excreted in urine.
Write two differences between DNA and RNA.
Why can azeotropic mixture not be separated by fractional distillation?
Why is molecularity applicable only for elementary reactions and order is applicable for elementary as well as complex reactions?
Deficiency of vitamin B$_1$ causes the disease :
Assertion (A): First ionisation enthalpy of Cr is lower than that of Zn.
Reason (R): Zinc is a non-transition element.
Assertion (A): Aquatic species are more comfortable in cold water than in warm water.
Reason (R): Solubility of oxygen gas in water decreases with increase in temperature.

Which of the following amines does not give foul smell of isocyanide on heating with chloroform and ethanolic KOH ?

The reaction

suggests that phenol is :

Anilinium hydrogen sulphate on heating at 453–473 K produces which of the following as a major product ?