Question

Calculate the ph when the following quantities of a 0.1M NaoH solution have been added to 50 mL of 0.1M Hcl solution 49.0mL

Answer 1

To calculate the pH when NaOH is added to HCl, determine the moles of acid and base, calculate the limiting reactant, find the moles of excess reactant, calculate the concentration of the excess reactant, and use it to find the pH using the equation pH = -log[H+].

Step-by-step explanation:

To calculate the pH when NaOH is added to HCl, we need to determine the moles of acid and base and use the stoichiometry of the reaction. The reaction between HCl and NaOH is:

HCl(aq) + NaOH(aq) -> H2O(l) + NaCl(aq)

1. Calculate the moles of HCl using the given volume and concentration:

• Moles of HCl = volume of HCl solution (L) x concentration of HCl (mol/L)

Calculate the moles of NaOH using the given volume and concentration:

• Moles of NaOH = volume of NaOH solution (L) x concentration of NaOH (mol/L)

Determine the limiting reactant, which is the reactant with fewer moles:

• In this case, it is the HCl as its moles are less than the moles of NaOH

Calculate the moles of excess reactant left:

• Moles of excess reactant = moles of limiting reactant - moles of reacted reactant

Calculate the concentration of the excess reactant in the final solution:

• Concentration of excess reactant = moles of excess reactant / volume of final solution (L)

Calculate the pH using the concentration of the excess reactant:

• pH = -log[H+]
• [H+] = concentration of excess reactant

Plug in the values into the equation to determine the pH.