Suppose that ammonia, applied to a field as a fertilizer, is washed into a farm pond containing 3.0 × 106 l of water. if the ph of this pond is found to be 9.81, what volume of liquid ammonia found its way into the pond? [given: kb(nh3) = 1.8 × 10–5; the density of liquid ammonia is 0.771 g/cm3]

19,7 L of ammonia.

Explanation:

The reaction of NH₃ with water is:

NH₃ + H₂O ⇄ NH₄⁺ + OH⁻ With kb = 1,8x10⁻⁵

OH⁻ concentration is:

[OH⁻] = = 6,46x10⁻⁵ M

That is the same than [NH₄⁺]

Also, Kb is:

kb =

Replacing:

[NH₃] = 2,32x10⁻⁴ M

Total volume is 3,0x10⁶ L, thus:

2,32x10⁻⁴ M + 6,46x10⁻⁵ M =

= 889,8 moles of NH₃ + NH₄⁺

These moles were initially just of liquid ammonia, thus, volume of ammonia added into the pond is:

889,8 mol NH₃ ₓ = 19,7 L of ammonia

I hope it helps!

1.43 x 10^-11 j the guy commented the awnser just making sure u see it .