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

State second law of electrolysis

Complete the given chemical equations 

`F_2 + 2Cl^(-)`

What happens when HCl is added to MnO₂? Write the equations involved

Give reasons Thermal stability decreases from H₂O to H₂Te.

Write the hybridisation and magnetic character of [Co(C₂O₄)₃]^3–.

(At. no. of Co = 27)

Calculate the mass of Ag deposited at cathode when a current of 2 amperes was passed through a solution of AgNO₃ for 15 minutes.

(Given : Molar mass of Ag = 108 g mol⁻¹ lF = 96500 C mol⁻¹)

Draw the structures of `H_3PO_2`

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?