Essential Question How does competition affect markets? > How does
the level and intensity of competition affect markets for goods and
services? Suppose you walked into a store selling running shoes under
each of the following conditions. For each example, briefly describe the
variety and quantity of running shoes you would expect to find and the
prices of the shoes.
• This store is one of eight independent stores selling running shoes in
the city.
• This store is one of three stores selling running shoes in the city, but
all three owners secretly work together to increase their profits.
• This store is the only one selling running shoes in the entire city.

The concentration of NH₄NO₃ required to make [OH⁻]  = 1.0 × 10⁻⁵ in a 0.200-m solution of NH₃ is 0.3639 M

Explanation:

Here we have

The reaction of Ammonia and water to produce OH⁻

NH₃ + H₂O → NH₄⁺ + OH⁻

From Henderson-Hasselbalch Equation for bases we have

pOH = pKb + log[acid]/[base]

The concentration of OH⁻ is given as [OH⁻] = 1.0 × 10⁻⁵

Therefore pOH = -log [OH⁻]  = -log(1.0 × 10⁻⁵) = 5

The base dissociation constant is given by  

kb = [B⁺][OH⁻]/[BOH]

For NH₃, kb = 1.8×10⁻⁵

pKb = -log Kb = 4.74

From the Henderson-Hasselbalch Equation

The acid concentration  = [NH₄⁺] and the base concentration = [NH₃] = 0.200 M

pOH = pKb + log ([acid]/[base])

Substituting the values, we have

5 = 4.74 + log ([ NH4+ ]/0.200 M)

[NH4+] = 1.8197×0.200 M = 0.3639 M

NH₄NO₃ → NH₄⁺ + NO₃⁻

Therefore, since one mole of NH₄NO₃, produces one mole of NH₄⁺, the number of moles of NH₄NO₃ required to produce  0.3639 M of NH₄⁺ is 0.3639 M of NH₄NO₃

The concentration of NH₄NO₃ required to make [OH⁻]  = 1.0 × 10⁻⁵ in a 0.200-m solution of NH₃ = 0.3639 M