CBSE 11TH CHEMISTRY - Online Test

Q1. General electronic configuration of s-block elements is:
Answer : Option C
Explaination / Solution:

The elements of Group 1 (alkali metals) and Group 2 (alkaline earth metals) which have ns1 and ns2 outermost electronic configuration belong to the s-Block Elements. The general electronic configuration of the valence shell for s-block elements is ns1-2.

Q2. Experiments on electrical discharge through gases ultimately lead to the discovery of
Answer : Option B
Explaination / Solution:

Towards the end of the 19th century Joseph J.Thomson (1856-1940) was studying electric discharges at the well-known Cavendish laboratory in Cambridge, England. Several people had been studying the intriguing effects in electric discharge tubes before him. Spectacular glows could be observed when a high voltage was applied in a gas volume at low pressure. It was known that the discharge and the glow in the gas were due to something coming from the cathode, the negative pole of the applied high voltage. Thomson made a series of experiments to study the properties of the rays coming from the cathode. He observed that the cathode rays were deflected by both electric and magnetic fields - they were obviously electrically charged. By carefully measuring how the cathode rays were deflected by electric and magnetic fields, Thomson was able to determine the ratio between the electric charge (e) and the mass (m) of the rays. Thomson's result was 

The particle that J.J.Thomson discovered in 1897, the electron, is a constituent of all the matter we are surrounded by. All atoms are made of a nucleus and electrons. He received the Nobel Prize in 1906 for the discovery of the electron, the first elementary particle.


Q3. Dissolved pollutant gases can form :
Answer : Option C
Explaination / Solution:

Pollutant gases dissolve in water in atmosphere to form Acid rain.

2SO2 + 2H2O + O2 -------> 2H2SO4


Q4. Zeolite/permutit process is also called
Answer : Option D
Explaination / Solution:

Zeolites/Permutits are sodium alluminium silicates. There process is known as ion exchange process used to remove permanent hardness of water.

Q5. Octet of electrons, represents a particularly stable electronic arrangement. Atoms achieve the stable octet when they are linked by chemical bonds. This rule is associated with one of the following theories
Answer : Option D
Explaination / Solution:

G.N.Lewis, proposed the octet rule to explain the valence electron sharing between atoms that resulted in a bonding type with the atoms attaining noble gas electronic configuration. The statement is : "a bond is formed between two atoms by mutual sharing of pairs of electrons to attain a stable outer-octet of electrons for each atom involved in bonding". This type of valence electron sharing between atoms is termed as covalent bonding.

Q6. Washing soda is
Answer : Option C
Explaination / Solution:

Washing soda is 
Q7.
 represents methoxypropane  and ethoxyethane 

Answer : Option D
Explaination / Solution:

rearrangement of carbon atoms around the functional group is known as metamerism.

Q8.
The drain cleaner, Drainex contains small bits of aluminum which react with caustic soda to produce dihydrogen. What volume of dihydrogen at  and one bar will be released when 0.15g of aluminum reacts?
Answer : Option B
Explaination / Solution:



Moles of Al= 0.15/27 =0.0055 moles And 2 mole of Al produces 3 moles of  so 0.0055 moles will produce 3/2x0.0055 moles of  =0.00825 moles. Now PV=nRT where n=0.00825 , P=1 bar and T=293K.

Q9. The pH of neutral water at  is 7.0. As the temperature increases, ionisation of water increases, however, the concentration of  ions and  ions are equal. What will be the pH of pure water at 
Answer : Option C
Explaination / Solution:

pH of water will be around 7 only. Water will be neutral even at 60°C

Q10.

In the free or the uncombined state, each atom in O2O3,P4,S8 and Mg has the oxidation number


Answer : Option D
Explaination / Solution:

In free or uncombined state each element has zero oxidation state.