Question & Answer: What solution is more basic and why NaOH, Nh3/h2o, na2co3…..

Basic solution = will have ploenty of OH- in solution, OH- > H+; and pH > 7, or pOH < 7

then, knowing this

NaOH = strong base, will donate OH- 100% to solution so [OH-] is high in concentration

NH3/H2O mix = forms NH4+ and OH-, it has OH- as well, but not in 100%, rather about 5-10 % in solution, so it is lower than NaOH

finally

NA2CO3 = 2Na+ + CO3-2; note that CO3-2 acts as a base with water;

CO3-2 + H2O = HCO3- + OH-; also form OH- but in a much lower extent than NH3 + NaOh

therefore

the best answer, which is the MOST BASIC, will be NaOH, a strong base