Forecast whether an aqueous solution can be made up to have

Question

Forecast whether an aqueous solution can be made up to have the subsequent concentrations or whether a chemical reaction must occur:

(a) 0.25 M CH3COONa and 0.15 M HI

(b) 0.050 M KNO2 and 0.18 M KNO3

(c) 0.0050 M Ca(OH)2 and 0.0010 MHNO3

(d) 0.20 M NH4Cl and 0.35 M NaOH