**Solution:**

To find the pH of the resulting solution, we need to calculate the concentration of the resulting solution after the mixing of HCl and NaOH.

**Step 1: Calculate the moles of HCl and NaOH:**

- Moles of HCl = Volume (in liters) x Concentration = 0.050 L x 0.1 M = 0.005 moles
- Moles of NaOH = Volume (in liters) x Concentration = 0.0499 L x 0.1 M = 0.00499 moles

**Step 2: Determine the limiting reactant:**

The limiting reactant is the one that is completely consumed in the reaction. In this case, HCl and NaOH react in a 1:1 stoichiometric ratio. Since the moles of NaOH is less than the moles of HCl, NaOH is the limiting reactant.

**Step 3: Determine the excess reactant:**

Since NaOH is the limiting reactant, HCl is the excess reactant. The remaining moles of HCl can be calculated as the difference between the initial moles of HCl and the moles used in the reaction.

- Moles of HCl remaining = Moles of HCl - Moles of NaOH used = 0.005 moles - 0.00499 moles = 0.00001 moles

**Step 4: Calculate the concentration of the resulting solution:**

The total volume of the resulting solution is the sum of the volumes of HCl and NaOH, i.e., 50 ml + 49.9 ml = 99.9 ml = 0.0999 L

The concentration of the resulting solution can be calculated by dividing the moles of the excess reactant (HCl) by the total volume of the solution.

- Concentration of the resulting solution = Moles of HCl remaining / Total volume of solution = 0.00001 moles / 0.0999 L = 0.100 M

**Step 5: Calculate the pH of the resulting solution:**

The pH of a strong acid solution can be calculated using the formula:

- pH = -log[H+]

Since HCl is a strong acid, it completely dissociates in water to give H+ ions. Therefore, the concentration of H+ ions is equal to the concentration of the resulting solution.

- pH = -log(0.100) = 1

Thus, the pH of the resulting solution is 1.

H+ conc . = N1V1 -N2V2 / V1 +V2


so H+ conc = 10^-4


therefore Ph = 4
hope u get it