Which of the following aqueous solutions are good buffer systems?
0.35 M barium bromide + 0.21 M sodium bromide
0.21 M hydrobromic acid + 0.21 M sodium bromide
0.20 M calcium hydroxide + 0.27 M calcium chloride
0.18 M hydrocyanic acid + 0.22 M potassium cyanide
0.29 M ammonia + 0.36 M barium hydroxide
acidic buffer is formed by weak acid and its conjugate base
basic buffer is formed by weak base and its conjugate acid
Option 1:
BaBr2 is salt and NaBr is slat.
They will not form buffer.
Option 2:
HBr is strong acid
NaBr is its salt.
They will not form buffer.
Option 3:
Ca(OH)2 is string base.
CaCl2 is its salt.
They will not form buffer.
Option 4:
HCN is weak acid.
KCN is its conjugate base.
They will form buffer
Option 5:
NH3 and Ba(OH)2 are both base
They will not form buffer.
Answer: option 4