CBSE 11TH CHEMISTRY - Online Test

Answer : Option C
Explaination / Solution:

Compounds are made when, atoms of two or more different elements combine together in fixed ratio to form molecules .(viz. water , ammonia , carbon- di- oxide glucose etc. ) . Thus the particles of compound consists of molecules.

Answer : Option D
Explaination / Solution:

The number of water molecules from the gaseous state into the liquid state also increases till the equilibrium is attained.

i.e.rate of evaporation = rate of condensation
H2O(l) ⇌  H2O (vap)

At equilibrium the pressure exerted by the water molecules at a given temperature remains constant and is called the equilibrium vapour pressure of water increases with temperature.

Answer : Option A
Explaination / Solution:

The intermolecular force primarily responsible for the condensed states of nonpolar substances is the dispersion force (or London force).

Answer : Option A
Explaination / Solution:

n-pentane CH3CH2CH2CH2CH3

2-Methylbutane CH3CH(CH3)CH2CH3

2,2-Dimethylpropane CH3CH(CH3)2CH3

Answer : Option A
Explaination / Solution:

On placing a strip of mettallic zinc in an aqueous solution of copper nitrate for about one hour, the copper nitrate solution turns green in colour and zinc strip turns darker. 

Formula and Ionic equation for the reaction is as follows.

Formula Equation:	Zn (s) + Cu(NO3)2 (aq) → Cu (s) + Zn(NO3)2 (aq)
Ionic Equation:	Zn (s) + Cu2+ (aq) → Zn2+ (aq) + Cu (s)

As is seen in ionic equation Zn is loosing 2 electrons, thus oxidation  occurs  and Cu is gaining 2 electrons, thus reduction occurs. Since oxidation and reduction takes place simultaneously in this reaction, it is a redox reaction. Also since Zn is loosing electrons and becoming darker in colour, it is the reducing agent and Cu is gaining 2 electrons, it is the reducing agent. The resultant solution Zinc nitrate [Zn(NO3)2] is green in colour.

Answer : Option D
Explaination / Solution:

Modern Periodic Law can be stated that the physical and chemical properties of the elements are periodic functions of their atomic numbers

Answer : Option C
Explaination / Solution:

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Answer : Option D
Explaination / Solution:

Rutherford's model of an atom : Ernest Rutherford was interested in knowing how the electrons are arranged within an atom. Rutherford designed an experiment for this. In this experiment, fast moving alpha (α)-particles were made to fall on a thin gold foil.

On the basis of his experiment, Rutherford put forward the model of an atom, which had the following features:

• There is a positively charged centre in an atom called the nucleus.
• Nearly all the mass of an atom resides in the nucleus. The electrons revolve around the nucleus in well-defined orbits.
• The size of the nucleus is very small as compared to the size of the atom.

Answer : Option C
Explaination / Solution:

Stratosphere, which is the second layer of atmosphere, contains ozone layer that absorbs UV-radiation from sun's rays.

Answer : Option B
Explaination / Solution:

The name ‘gas giant’ was coined in 1952 by science fiction writer James Blish to refer to all the giant planets. The giant planets (Jupiter and Saturn) are huge gas balls, which is quite different than Earth and and other three rocky inner planets. Gas giants are primarily composed of gases, such as hydrogen and helium, and a much thicker layer of metallic hydrogen, along with a molten rocky core. Unlike rocky planets, gas giants do not have a well-defined surface, and there is no clear boundary between where the atmosphere ends and the surface begins. In other words, you wouldn’t be able to land on these planets, as their atmospheres simply become gradually denser towards the core, perhaps with liquid or liquid-like states somewhere in between.