posted by CANDY on .
HOW CAN U TELL IF HNO3 +KNO3 IS A BUFFER SOLUTION
A buffer solution must contain a weak acid and its conjugate base OR a weak base and its conjugate acid. HNO3 is a strong base and KNO3 is the salt of a strong base (KOH) and a strong acid (HNO3); therefore, it doesn't qualify as a buffer solution. Acetic acid and sodium acetate could be made into a buffer. NH3 and NH4Cl can be a buffer. HF and NaF can be a buffer. Get the picture? I have given you the definition. Perhaps you actually want to know how you can tell (by experiment??) whether a solution is buffered. Take a solution of HNO3 + KNO3. Add moderate amount of NaOH and see if the pH changes significantly. It will. A buffered solution will not. (Having said all of this, in real practice, a very strong solution of a strong acid acts just like a buffered solution until it is partially neutrlized. Technically, then, a strong solution of HNO3 will resist a change in pH when KOH is added.)