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: K_b(NH₃)= 1.8 × 10^-5; the density of liquid ammonia is 0.771 g/cm³] A)15 L B)25 L C)11 L D)19 L E)320 L

Question

Quizplus · Accepted Answer

First, we need to use the given equilibrium constant for ammonia in water to calculate the concentration of NH3 in the pond:

[NH3] = (Kb[H2O])/[NH4+]
[NH3] = (1.8 × 10^-5)(10^-14.19)/10^-9.81
[NH3] = 4.8 × 10^-10 M

Next, we can use the density of liquid ammonia to convert the concentration to a mass of ammonia:

0.771 g/cm^3 x 1000 cm^3/L = 771 g/L
mass NH3 = 4.8 × 10^-10 M x 17 g/mol x 30000 L x 771 g/L
mass NH3 = 23.6 g

Finally, we can convert the mass of ammonia to a volume using the density:

volume NH3 = 23.6 g / 0.771 g/cm^3
volume NH3 = 30.6 cm^3 or 0.03 L

Therefore, the answer is D) 19 L.

Suppose That Ammonia, Applied to a Field as a Fertilizer