Science (English Medium) Class 12 - CBSE Question Bank Solutions for Chemistry

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.

Complete the following reactions:

Complete the following reactions:

Define the following terms :

Limiting molar conductivity

Write the chemical equations to illustrate the following name reactions:

Aldol condensation

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

Draw the structures of the following compounds :

 N₂O₅

Write balanced chemical equations involved in the following reactions: 
Calcium phosphide is dissolved in water. 

 How can you determine limiting molar conductivity,   0 m for strong electrolyte and weak electrolyte?

 An element crystallises in bcc lattic with a cell edge of 3 × 10^-8cm. The density of the element is 6.89 g cm^-3 . calculate the molar mass of element. (N_A = 6.022 × 10²³ mol^-1)

Write the structure of the monomer used in the following polymer:
Buna-S

Write the product formed when p-nitro chlorobenzene is heated with aqueous  NaOH at 443K followed by acidification? 

complete the following reaction: 

complete the following reaction: 

\[\begin{array}{cc}
\phantom{...}\ce{CH3} \\
| \\
\phantom{.................}\ce{CH3-CH-COOH ->[(i) Br2/Red P4][(ii)H2O]}
\end{array}\]

A steady current of 2 amperes was passed through two electrolytic cells X and Y connected in series containing electrolytes FeSO₄and ZnSO₄ until 2.8g of Fe deposited at the cathode of cell X. How long did the current flow? Calculate the mass of Zn deposited at the cathode of cell Y. 
(Molar mass: Fe=56g mol^-1,Zn=65.3g mol^-1,1F=96500C mol^-1)

In the plot of molar conductivity (∧_m) vs square root of concentration (c^1/2) following curves are obtained for two electrolytes A and B : 

Answer the following:
(i) predict the nature of electrolytes A and B.
(ii) What happens on the extrapolation of ∧_m to concentration approaching for electrolytes A and B?

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

What is the role of Sulphur in the vulcanization of rubber?

In the plot of molar conductivity (∧_m) vs square root of concentration (c^1/2), following curves are obtained for two electrolytes A and B:

Answer the following:
(i) Predict the nature of electrolytes A and B.
(ii) What happens on extrapolation of ∧_m to concentration approaching zero for electrolytes A and B?

Complete the following reaction: