Question

Calculate ph of 1L solution containing 10 mL of 5m NaOH.

Answer 1

To calculate the pH of the solution, we first need to calculate the concentration of hydroxide ions ([OH-]). Then, we can use this concentration to calculate the concentration of hydronium ions ([H3O+]). Finally, we can find the pH by taking the negative logarithm of the hydronium ion concentration.

Step-by-step explanation:

To calculate the pH of a 1L solution containing 10mL of 5M NaOH, we need to first calculate the concentration of hydroxide ions ([OH-]) in the solution.

1. Given that the volume of NaOH solution is 10mL and its concentration is 5M, we can calculate the moles of NaOH:

• Moles of NaOH = (volume of NaOH solution) x (concentration of NaOH) = 10mL x 5M = 50mmol

Since NaOH is a strong base, it dissociates completely in water to give hydroxide ions (OH-) and sodium ions (Na+).In a 1L solution, the total volume is 1L = 1000mL.Therefore, the total volume of the solution = 1000mL + 10mL = 1010mL.To calculate the concentration of [OH-] in the final solution, we can use the formula:

[OH-] = (moles of NaOH) / (total volume of solution in liters)

1. Using the values we calculated:

[OH-] = 50mmol / 1.01L = 49.5mM

1. To calculate the pH, we need to find the concentration of hydronium ions ([H3O+]). However, since we have the concentration of hydroxide ions ([OH-]), we can use the formula:

[H3O+] = 10^-14 / [OH-]

1. Substituting the value we calculated for [OH-]:

[H3O+] = 10^-14 / 49.5mM = 2.02 x 10^-16M

1. Finally, calculating the pH:

pH = -log [H3O+] = -log (2.02 x 10^-16) = 15.7