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

Write the name of the cell which is generally used in transistors. Write the reactions taking place at the anode and the cathode of this cell.

Why is [NiCl₄]²⁻ paramagnetic while [Ni(CN)⁴]²⁻ is diamagnetic? (Atomic number of Ni = 28)

 Following reactions occur at cathode during the electrolysis of aqueous copper(II) chloride solution :

On the basis of their standard reduction electrode potential (E°) values, which reaction is feasible at the cathode and why ?

Write the hybridization type and magnetic behaviour of the complex [Ni(CN)₄]²⁻. (Atomic number of Ni = 28)

An element X (molar mass = 60 g mol⁻¹) has a density of 6.23 g cm⁻³. Identify the type of cubic unit cell, if the edge length of the unit cell is 4 ✕ 10⁻⁸ cm.

Account for the following :

Reducing character decreases from SO2 to TeO₂.

Define an ideal solution and write one of its characteristics.

After the ban on plastic bags, students of a school decided to make people aware of the harmful effects of plastic bags on the environment and Yamuna River. To make the awareness more impactful, they organised a rally by partnering with other schools and distributed paper bags to vegetable vendors, shopkeepers and departmental stores. All the students pledged not to use polythene bags in the future to save the Yamuna River.

After reading the above passage, answer the following questions:
(i) What values are shown by the students?
(ii) What are bio-degradable polymers? Give one example.
(iii) Is polythene a condensation or an addition polymer?

Arrange the following in the order of the property indicated against set :
H₂O, H₂S, H₂Se, H₂Te − increasing acidic character.

Write the product formed on reaction of D-glucose with Br₂ water.

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

 Account for the following: 
On reaction with benzene sulphonyl chloride, primary amine yields product soluble in alkali whereas secondary amine yields product insoluble in alkali.

 What is the role of promoters and poisons in catalysis?

 Give reactions for the following: 
O – O single bond is weaker than S – S single bond. 

Write chemical equation in support of your answer. 
 Out of   Cl and  CH₂- Cl,  which one is more reactive towards nucleophilic substitution reaction and why? 

Write chemical equation in support of your answer. 
 Out of  Cl and O2N Cl. which one is more reactive  towards nucleophilic substitution reaction and why?

Arrange the following in order of the property indicated set.
HF, HCl, HBr, HI - decreasing bond enthalpy.

Out of (CH₃)₃ C-Br and (CH₃)₃ C-I, which one is more reactive towards S_N1 and why? 

Write the hybridization and magnetic character of the following complexes:
[Fe(H₂O)₆]²⁺
(Atomic no. of Fe = 26)

Write the hybridization and magnetic character of the following complexes:
[Fe(CO)₅]
(Atomic no. of Fe = 26)