Answer:
0.40 M HCN and 0.10 KCN
Explanation:
A buffer solution is defined as the aqueous mixture of a weak base and its conjugate base or vice versa.
For the systems:
0.10 M KCN 0.20 M CH3COOH: Acetic acid, CH₃COOH is a weak acid and KCN is the conjugate base of HCN. Here, you have a weak acid and a conjugate base but not the conjugate base of the acetic acid or the weak acid of KCN. Thus, it is not a buffer.
1.0 M HNO3 and 1.0 M NaNO3. HNO₃ is a strong acid. Thus, this system is not a buffer.
0.40 M HCN and 0.10 KCN. Here, you have HCN, the weak acid, and KCN, its conjugate base. Thus, it is a buffer.
0.50 M HCl and 0.10 NaCl. HCl is a strong acid, thus, its mixture with NaCl is not a buffer.
The solution that has been able to form the buffer has been 0.40 M HCN and 0.10 M KCN. Thus, option C is correct.
Buffer solution has been formed with the dissolution of the acid with conjugate base.
The the buffer solution has been aqueous solution of the weak acid or base, that has been changed in pH with the addition of small amount of strong acid or base.
The given solutions can be assessed as:
KCN has been conjugate base of HCN, not acetic acid. Thus it is not a buffer.
Nitric acid has been a strong base, and is unable to form a buffer system.
HCN has been a weak acid, and KCN has been the conjugate base. Thus, it has been able to form the buffer system.
HCl has been a strong acid, and has been unable to form the buffer solution.
Thus, the solution that has been able to form the buffer has been 0.40 M HCN and 0.10 M KCN. Thus, option C is correct.
For more information about the buffer solution, refer to the link:
https://brainly.com/question/13833120
