Advertisement Remove all ads

Important Questions for CBSE (Science) Class 12 - CBSE

Subjects
Topics
Subjects
Popular subjects
Topics

Please select a subject first

Advertisement Remove all ads
Advertisement Remove all ads
< prev  1 to 20 of 4939  next > 

Draw the structures of the following molecules: XeF4

Appears in 23 question papers
Chapter: [0.07] P - Block Elements
Concept: P - Block Group 18 Elements > Concept of Group 18 Elements

Define terms: Fuel cell

Appears in 13 question papers
Chapter: [0.03] Electrochemistry
Concept: Batteries > Primary Batteries

Write the chemical equations involved in the following reactions:(i) Hoffmann-bromamide degradation reaction

Appears in 12 question papers
Chapter: [0.13] Organic Compounds Containing Nitrogen
Concept: Amines > Preparation of Amines

Write two important advantages of reflecting telescope over a refracting telescope.

Appears in 12 question papers
Chapter: [0.09] Ray Optics and Optical Instruments
Concept: Optical Instruments > Telescope

Amino acids show amphoteric behaviour. Why?

Appears in 11 question papers
Chapter: [0.14] Biomolecules
Concept: Proteins > Amino Acids

How do you convert the Toluene to Benzoic acid

Appears in 10 question papers
Chapter: [0.12] Aldehydes, Ketones and Carboxylic Acids
Concept: Acids > Nomenclature of Carboxylic Acids

Illustrate the following reaction giving suitable example in each case:Gabriel phthalimide synthesis

Appears in 10 question papers
Chapter: [0.13] Organic Compounds Containing Nitrogen
Concept: Amines > Preparation of Amines

Define the following terms: Essential amino acids

Appears in 10 question papers
Chapter: [0.14] Biomolecules
Concept: Proteins > Amino Acids

Why is bithional added to soap?

Appears in 10 question papers
Chapter: [0.16] Chemistry in Everyday Life
Concept: Cleansing Agents - Soaps

State the two Kirchhoff’s rules used in electric networks. How are there rules justified?

Appears in 10 question papers
Chapter: [0.03] Current Electricity
Concept: Kirchhoff’s Rules

In a single slit diffraction experiment, the width of the slit is made double the original width. How does this affect the size and intensity of the central diffraction band?

Appears in 10 question papers
Chapter: [0.1] Wave Optics
Concept: Diffraction of Light > The Single Slit

Define a wavefront

Appears in 10 question papers
Chapter: [0.1] Wave Optics
Concept: Huygens' Principle

Give the truth table and circuit symbol for NAND gate

Appears in 10 question papers
Chapter: [0.14] Semiconductor Electronics - Materials, Devices and Simple Circuits
Concept: Digital Electronics and Logic Gates

An element 'X' (At. mass = 40 g mol-1) having f.c.c. the structure has unit cell edge length of 400 pm. Calculate the density of 'X' and the number of unit cells in 4 g of 'X'. (NA = 6.022 × 1023 mol-1)

Appears in 9 question papers
Chapter: [0.01] Solid State
Concept: Number of Atoms in a Unit Cell

Calculate the freezing point of a solution containing 60 g of glucose (Molar mass = 180 g mol–1) in 250 g of water. (Kf of water = 1.86 K kg mol–1)

Appears in 9 question papers
Chapter: [0.02] Solutions
Concept: Colligative Properties and Determination of Molar Mass > Depression of Freezing Point

Give reasons for the following:

Measurement of osmotic pressure method is preferred for the determination of molar masses of macromolecules such as proteins and polymers.

Appears in 9 question papers
Chapter: [0.02] Solutions
Concept: Colligative Properties and Determination of Molar Mass > Depression of Freezing Point

Give reasons for the following :

Aquatic animals are more comfortable in the cold water than in warm water.

Appears in 9 question papers
Chapter: [0.02] Solutions
Concept: Solubility > Solubility of a Gas in a Liquid

Give reasons for the following

Elevation of the boiling point of 1 M KCl solution is nearly double than that of 1 M sugar solution.

Appears in 9 question papers
Chapter: [0.02] Solutions
Concept: Abnormal Molar Masses

Write the cell reaction and calculate the e.m.f of the following cell at 298 K:

`Sn(s) | Sn^(2+) (0.004 M) || H^(+) (0.020 M) | H_2 (g) ("1 bar") | Pt(s)`

(Given: `E_(Sn^(2+)"/"Sn)^0 = -0.14` V)

Appears in 9 question papers
Chapter: [0.03] Electrochemistry
Concept: Galvanic Cells - Measurement of Electrode Potential

Give reasons On the basis of E° values, O2 gas should be liberated at anode but it is Cl2 gas which is liberated in the electrolysis of aqueous NaCl.

Appears in 9 question papers
Chapter: [0.03] Electrochemistry
Concept: Conductance of Electrolytic Solutions > Measurement of the Conductivity of Ionic Solutions
< prev  1 to 20 of 4939  next > 
Advertisement Remove all ads
Advertisement Remove all ads
Share
Notifications

View all notifications


      Forgot password?
View in app×