I don't know if you are to calculate these or not.
Approx pH values are NaOH is about 12, NaHCO3 is about 8, NaCl is about 7, NH4Cl is about 5. You will need to calculate the pH of NH4ClO2. I don't remember those Ka or Kb values. (H^+) = sqrt(Kw/KaKb) and fit that into the scheme above. I think pH of NH4ClO2 will fall as the lowest pH (strongest acidity).
Arrange the solutions in order of increasing acidity.
NaCl, NH4Cl, NaHCO3, NH4CLO2, NaOH
4 answers
nacl
NaOH, NaHCO3, NaCl, NH4ClO2, NH4Cl
How did you figure out the order of increasing acidity.