CBSE 11TH CHEMISTRY - Online Test
Q1. For an adiabatic change
Answer : Option B
Explaination / Solution:
An adiabatic process would not allow exchange of heat between the system and surroundings, hence q=0.
Q2. Generally, the first ionization energy increases along a period including some exceptions. One which is NOT an exception is ______.
Answer : Option B
Explaination / Solution:
The high ionization energy of B, N and Mg is due to the presence of stable electronic configuration in these atoms as compared to the next element in the period. For ex. Be (Is2 2s2) has competely filled orbitals as compared to B (1s2 2s2 2p1) where there is one electron in p-orbital that can easily be lost. Therefore, B has a lower ionization energy than Be.
Q3. How many neutrons and protons are there in the nucleus?
Answer : Option A
Explaination / Solution:
Number of protons = Atomic number =6
Number of neutrons = atomic mass - no of protons = 13-6 = 7
Q4. Three elements needed for the healthy growth of plants are
Answer : Option D
Explaination / Solution:
Nitrogen , phosphorus, and potassium are needed.
Q5. is an example of
Answer : Option B
Explaination / Solution:
Water present in the interstitial sites in a crystal lattice is known as interstitial water. They are not held by hydrogen bonding with the other elements. If they are bonded they are called H-bonded hydrates.
Barium chloride is a white crystalline powder. It contains two molecules of water. It is one of the most important water soluble salts of Barium.
Q6. Ionic crystalline compounds formed by ion-formation by electron transfer proves
Answer : Option D
Explaination / Solution:
Ionic crystalline compounds formed by ion-formation by electron transfer proves electronic theory of chemical bonding.
Q7. Why is paramagnetic ?
Answer : Option C
Explaination / Solution:
is a superoxide ( 3 electron species) so has one unpaired electron thus it is paramagnetic.
Q8. The fragrance of flowers is due to the presence of some steam volatile organic compounds called essential oils. These are generally insoluble in water at room temperature but are miscible with water vapour in vapour phase. A suitable method for the extraction of these oils from the flowers is:
Answer : Option C
Explaination / Solution:
A suitable method for the extraction of these oils from the flowers is Steam distillation
Q9. What will be the minimum pressure required to compress 500 of air at 1 bar to 200 at
Answer : Option A
Explaination / Solution:
Using ideal gas equation, PV=nRT,
since T is constant, we have
Q10. Which of the following is not a general characteristic of equilibria involving physical processes?
Answer : Option D
Explaination / Solution:
All the physical processes stop at equilibrium.
