Explanation:
Transition metals occupy the d block of the periodic table. Their location is right between the group 2A and 3A. Copper (Cu) is in the first row of the d-block elements. The image attached illustrates the position of the transition metals relative to other elements in the periodic table.
Answer : The correct option is, (A) a solution that is 0.10 M and 0.10 M
Explanation :
Buffer : It is defined as a solution that maintain the pH of the solution by adding the small amount of acid or a base.
As we know that there are two types of buffer which are acidic buffer and basic buffer.
Acidic buffer : It is defined as the solution that have the pH less than 7 and it contains weak acid and its salt or conjugate base. For example : Acetic acid (weak acid) and sodium acetate (salt or conjugate base).
Basic buffer : It is defined as the solution that have the pH more than 7 and it contains weak base and its salt or conjugate acid. For example : Ammonia (weak base) and ammonium chloride (salt or conjugate acid).
(A) a solution that is 0.10 M and 0.10 M
It is a mixture of weak acid and its conjugate base (salt)
. So, it is a good buffer.
(B) a solution that is 0.10 M HF and 0.10 M
It is not a buffer system because is not a salt of weak acid HF.
(C) a solution that is 0.10 M HCl and 0.10 M
It is not a buffer because HCl is a strong acid.
(D) a solution that is 0.10 M NaOH and 0.10 M KOH
It is not a buffer because NaOH and KOH are a strong base.
Hence, the correct option is, (A)