1. A student wishes to determine the concentration of a solution of KOH. The student adds 5.0mL of the KOH sol

1. A student wishes to determine the concentration of a solution of KOH. The student adds 5.0mL of the KOH solution to 150mL of water, adds an idicator and titrates with 0.1206M HCL. If the titration requires 27.35mL, of acid, what is the concentration of the KOH solution? 2. A HCL solution has a density of 1.27g/ml and is 37.5% HCL by mass. What is the molarity of this HCL solution.

1. A student wishes to determine the concentration of a solution of KOH. The student adds 5.0mL of the KOH sol
1)find moles of HCL


using equation


moles = molarity x vol (in litres)





moles = 0.1206x 27.35x10^-3


moles HCl = 3.298 x 10^-3





one mole of KOH neutralised by one mole of HCL


therefore moles HCL = moles of KOH


now we can find molarity of KOH using as equation





moles = molarity x vol (litres)


3.298 X10^-3 = molarity x 155x10^-3 ( 150ml of water + 5mlKOH)


Thus molarity = (use your calculator should be approximately 0.02moldm-3)





2) i have an answer for this part but i get a really large number (13.06moldm-3), so I'm sure it is wrong!





hope this helps!


xxx