Which of the following solutions is the most basic? . a) 0.6m nh3. b) 0.150 m koh. c) 0.100 m ba(oh)2

The correct answer among the choices presented above is option C. Barium hydroxide is the most basic solution. This can be proved by calculating the concentration of OH- ions in the solution. The one with the highest OH- concentration is the most basic solution.

NH3 is a weak base 
NH3 + H2O <=> NH4+ + OH- 
Kb = 1.8 x 10^-5 = x^2/0.6-x 
x = [OH-]= 0.0033 M 

KOH is a strong base so [OH-]= 0.150 M 

Ba(OH)2 = Ba2+ + 2 OH- 
[OH-]= 2 x 0.100 = 0.200 M