Science (English Medium) Class 12 - CBSE Important Questions for Chemistry

What happens when CdCl₂ is doped with AgCl?

How will you convert the following in not more than two steps:

Benzoic acid to Benzaldehyde

How will you convert the following in not more than two steps:

Acetophenone to Benzoic acid

30 g of urea (M = 60 g mol⁻¹) is dissolved in 846 g of water. Calculate the vapour pressure of water for this solution if vapour pressure of pure water at 298 K is 23·8 mm Hg.

What is meant by negative deviation from Raoult's law? Give an example. What is the sign of ∆_mixH for negative deviation?

Calculate the mass of NaCl (molar mass = 58.5 g mol⁻¹) to be dissolved in 37.2 g of water to lower the freezing point by 2°C, assuming that NaCl undergoes complete dissociation. (K_f for water = 1.86 K kg mol⁻¹)

Account for the following :

H₂S has lower boiling point than H₂O.

Which of the two components of starch is water soluble?

Define an ideal solution and write one of its characteristics.

Account for the following:

PCl₅ is more covalent than PCl₃.

Some liquids on mixing form 'azeotropes'. What are 'azeotropes'?

State Henry's Law. What is the effect of temperature on the solubility of a gas in a liquid?

What type of intermolecular attractive interaction exists in the pair of methanol and acetone?

State Raoult's law for the solution containing volatile components. What is the similarity between Raoult's law and Henry's law?

Account for the following :

SnCl₄ is more covalent than SnCl₂.

 Arrange the following increasing order of their boiling point:
CH₃CH₂OH, CH₃CHO, CH₃–O–CH₃ 

 What happens when AgCl is doped with 2? CdCl What is the name of this defect? 

What type of defect is shown by NaCl in 
 stoichiometric defects, and

 non-stoichiometric defects?

 Out of 0.1 molal aqueous solution of glucose and 0.1 molal aqueous solution of KCl, which one will have higher boiling point and why?