Calculate the PH value of 1.00 L of a solution prepared by mixture of 1.00 mol HCl, 2.00 moles of NaOH and 1.50 moles of NH4Cl
Kb (NH3) = 1.8 * 10 ^-5
To calculate the pH value of the solution, we need to determine the concentration of hydroxide ions (OH-) in the solution. We can do this by first finding the concentration of ammonia (NH3) formed from the reaction between NH4+ and OH-.
1. Write the balanced chemical equation for the reaction between NH4Cl and NaOH:
NH4Cl + NaOH -> NH3 + H2O + NaCl
2. From the balanced equation, we can see that 1 mol of NH4Cl reacts with 1 mol of NaOH to produce 1 mol of NH3. Therefore, the concentration of NH3 will be the same as the concentration of NH4Cl.
Concentration of NH3 = 1.50 moles / 1.00 liters = 1.50 M
3. Since the reaction produced 1 mol of NH3 and 1.00 L of solution, the concentration of OH- formed from NH3 will also be 1.50 M.
4. Now, we need to calculate the concentration of OH- formed from the dissociation of water. At 25°C, the concentration of OH- formed from water can be considered as 1.00 x 10^-7 M.
5. Sum up the concentrations of OH- from NH3 and water:
Total OH- concentration = Concentration from NH3 + Concentration from water
Total OH- concentration = 1.50 M + 1.00 x 10^-7 M
6. Calculate the pOH value by taking the negative logarithm of the OH- concentration:
pOH = -log(Concentration of OH-)
7. Calculate the pH value using the formula:
pH = 14 - pOH
Substitute the values into the equation:
pOH = -log(1.50 M + 1.00 x 10^-7 M)
pH = 14 - pOH
By following these steps and performing the calculations, you can determine the pH value of the given solution.