Answer:
According to Le-chatelier principle, equilibrium will shift towards left to minimize concentration of 
and keep same equilibrium constant
Explanation:
In this buffer following equilibrium exists -
So, is involved in the above equilibrium.
When a strong base is added to this buffer, then concentration of increases. Hence, according to Le-chatelier principle, above equilibrium will shift towards left to minimize concentration of and keep same equilibrium constant.
Therefore excess amount of combines with 
to produce ammonia and water. So, effect of addition of strong base on pH of buffer gets minimized.
The answer is (3)Ne. Usually, the elements belongs to group 18 all have completely filled valence electron shell. Among the four elements carbon, vanadium, neon and antimony, only neon belongs to group 18.
Physical Change
It is being changed by the sun
Answer:
HNO₃.
Explanation:
- It is known that acids decrease the pH of the solution, while bases increase the pH of the solution.
So, HF and HNO₃ decrease the pH of the solution as they produce H⁺ in the solution.
While, KOH and NH₃ increase the pH of the solution as they produce OH⁻ in the solution.
HNO₃ will decrease the pH of the solution greater than HF.
- Because HNO₃ is strong acid that decomposes completely to produce H⁺ more than the same concentration of HF that is a weak acid which does not decomposed completely to produce H⁺.
