Chemistry - Online Test
Q1. Aquatic animals are more comfortable in cold water rather that warm water because
Answer : Option D
Explaination / Solution:
Because of increase in kinetic energy of gas molecules with temperature there tendency to escape from the liquid will increase.
Q2. One of the following behave like Lewis base
Answer : Option C
Explaination / Solution:
Amines behave as lewis base because of presence of lone pair on N, whereas in amides and cyanides the lone pair on nitrogen is involved in resonance. In esters, the lone pair on oxygen is involved in resonance.
Q3. One of the following has application in electrode processes and cells
Answer : Option B
Explaination / Solution:
The concept of redox reaction is used in electrode processes and cells. Because in these processes an electrode loose or gain electrons, electrode with higher reduction potential undergo reduction, electrode potential is given a positive sign if oxidation occures at the electrode.
Q4. Which type of solid conduct electricity in molten state but not in solid state?
Answer : Option A
Explaination / Solution:
In molten state ions can exist so they can conduct electricity
Q5. One of the following rubbers is used in making oil seals, tank lining, etc.
Answer : Option C
Explaination / Solution:
Buna N is used in making oil seals , tank linings.
Q6. The thermal stability of hydrides of group 16 elements decreases in the order
Answer : Option A
Explaination / Solution:
As we move down the group bond length increases and bond enthalpy for the dissociation of H-E bond decreases. Due to decrease in enthalpy the thermal stability of hydrides decreases down the group.
Q7. Enthalpy of solution of a substance is the enthalpy change
Answer : Option D
Explaination / Solution:
Enthalpy of solution of a substance is the enthalpy change when one mole of it dissolves in a specified amount of solvent
Q8. ZnCO3(s)−→ΔZnO(s) + CO2 ;The reaction shows the process of
Answer : Option C
Explaination / Solution:
Carbonate ore is heated to a high temperature in the absence of air is calcination
Q9. All the orbitals in the valence shell of the noble gases
Answer : Option A
Explaination / Solution:
These elements are called noble elements beacuse they contain ns2, np6 valence shell electronic configuration. A complete octet in the outermost shell makes these elements chemically stable, and therefore they do not easily react with other elements to form compounds.
Q10. According to quantum theoretical model of an atom each orbital is designated by three quantum numbers labelled as n, l and ml. The values these can take are
Answer : Option D
Explaination / Solution:
n (Principal quantum number) value tell about the shell to which the electro belong, Ex,If n=1 electron belongs to first shell (K) around the nucleus
l (Azimuthal quantum number) tell about angular momentum, and shape of the orbitals, and it designates the subshells to which the electron belongs to. For a given value of 'n', ' l' can have value ranging from 0 to n-1. Ex, If n=2 then , the value of 'l' will be 0 and 1 (0 to n-1)
ml ( Magnetic orbital quantum number) determines the number of preferred orientations of the orbitals in the subshell, which are defined by given 'l' value. ex if 'l'= 2 then ml = 2l+1 =2*2 +1= 5 m value ie., m = +2,+1,0,-2,-1
