Order these species by increasing concentration of H30+ in a 1.0 M aqueous solution. (From the solution with the least hydronium concentration to the solution with the most hydronium concentration)
NO
H2CO3, NH4, OH, HCO3, NH3, H20
Home
ir
H2CO3,NH4+, OH", HCO3, NH3,
H20
Paste
H20, H2CO3, NH4+, OH", HCO3-
NH3
6
con
O
OH", NH3, HCO3, H20, NH4+,
H2CO3
None of the answer choices are
correct.

OH⁻ < NH₃ < HCO₃⁻ < H₂O < NH₄⁺ < H₂CO₃

Explanation:

We can do some rough calculations to find the approximate pH values of these solutions.

H₂CO₃

Kₐ ≈ 10⁻⁶

NH₄⁺

Kb of NH₃ ≈ 10⁻⁵

Kₐ of NH₄⁺ ≈ 10⁻⁹

OH⁻

Strong base

[OH⁻] = 10⁻¹

pOH = 1

pH = 14 - 1 = 13

HCO₃⁻

Salt of dibasic acid

K₁ ≈ 10⁻⁶; K₂ ≈ 10⁻¹⁰

NH₃

Kb ≈ 10⁻⁵

pOH = 14 - 3 = 11

H₂O

Neutral. pH = 7

Order from lowest [H₃O⁺] to highest [H₃O⁺]:

      OH⁻ < NH₃ < HCO₃⁻ < H₂O < NH₄⁺ < H₂CO₃  

pH   1 3        11          8            7         5           3.5