Question

What is the ph of a solution made by mixing 25.00 ml of 0.100 m hcl with 40.00 ml of 0.100 m koh? assume that the volumes of the solutions are additive. what is the ph of a solution made by mixing 25.00 ml of 0.100 m hcl with 40.00 ml of 0.100 m koh? assume that the volumes of the solutions are additive. 1.64 0.64 13.36 12.36?

Answer 1

Answer: The HCl and KOH will react until one or the other is gone. As you have a larger volume of an equal concentration of HCl, the KOH will go first. moles HCl = 0.04000 L * 0.100 M = 0.00400 moles moles KOH = 0.02500 L * 0.100 M = 0.00250 moles moles HCl left = 0.00400 - 0.00250 = 0.00150 moles Your total volume is now 65.00 mL, so the [HCl] = 0.00150 moles / 0.06500 L = 0.0231 M = [H+] pH = -log [H+] = -log (0.0231) = 1.64