Final answer:
Ammonia reacts with hydrochloric acid in a 1:1 ratio to form ammonium chloride, and the final concentration of ammonium chloride after reacting 2.01 M NH₃ with 1.03 M HCl is approximately 0.386 M.
Step-by-step explanation:
When ammonia (NH₃) reacts with hydrochloric acid (HCl) to form ammonium chloride (NH₄Cl), the reaction is a stoichiometric one where one mole of NH₃ reacts with one mole of HCl to produce one mole of NH₄Cl.
To calculate the concentration of NH₄Cl in the final solution, we first find out how many moles of each reactant are present initially. For NH₃, 100.0 mL of a 2.01 M solution contains 0.201 moles (100.0 mL × 2.01 mol/L × 1 L/1000 mL), and for HCl, 60.00 mL of a 1.03 M solution contains 0.0618 moles (60.00 mL × 1.03 mol/L × 1 L/1000 mL).
The reaction goes to completion, and NH₃ is in excess, so all the HCl reacts. The amount of NH₄Cl formed is equal to the initial amount of HCl, which is 0.0618 moles.
To find the concentration of NH₄Cl in the final solution, we must consider the total final volume, which is 100.0 mL + 60.00 mL = 160.00 mL or 0.160 L. The concentration of NH₄Cl is then 0.0618 moles / 0.160 L, which is approximately 0.386 M. Therefore, the final concentration of NH₄Cl in the solution is 0.386 M.