Calculate the [h30+] in a solution prepared by mixing 25.0mL of 1.0M HCl with 50.0mL of 0.50M KOH?

Step by step guide:

HCl+KOH--> H2O+KCL

Moles of HCL = (25/1000) * 1 = 0.025moles

Moles of KOH = (50/1000) * 0.5 = 0.025moles

Therefore all the acid and alkaline has reacted to produce a neutral solution (pH7)

Therefore [H3O+] = 0