What is the concentration of ammonia in a solution if 24.20 mL of a 0.1140 M solution of HCl are needed to titrate a 100.0 mL sample of the solution?

To find the concentration of ammonia in the solution, we need to use the concept of stoichiometry and the balanced chemical equation of the reaction between ammonia (NH3) and hydrochloric acid (HCl).

The balanced chemical equation for the reaction between NH3 and HCl is as follows:

NH3 + HCl → NH4Cl

From the equation, we can see that the mole ratio between NH3 and HCl is 1:1. This means that for every 1 mole of NH3, we need 1 mole of HCl to react completely.

First, let's calculate the number of moles of HCl used in the titration:

Number of moles of HCl = (Volume of HCl) x (Molarity of HCl)
= (24.20 mL) x (0.1140 M)
= 2.7618 mmol (millimoles)

Since the mole ratio between NH3 and HCl is 1:1, the number of moles of NH3 in the solution is also 2.7618 mmol.

Next, we convert the volume of the solution from milliliters to liters:

Volume of solution = 100.0 mL = 0.1000 L

Finally, we can calculate the concentration of NH3 in the solution:

Concentration of NH3 = (Number of moles of NH3) / (Volume of solution)
= (2.7618 mmol) / (0.1000 L)
= 27.618 M

Therefore, the concentration of ammonia in the solution is 27.618 M.