[km]

How do I make 40 ml of KOH 0.5 N : EtOH (1:1 v/v)!!

[Nobby]

You need the molecular weight of pottasium hydroxide. From this you calculate how much a 0.5 n solution should be, You calculate down to 20 ml.
This amount you dissolve in 20 ml water. You add the same amount of alcohol.

[km]

You need the molecular weight of pottasium hydroxide. From this you calculate how much a 0.5 n solution should be, You calculate down to 20 ml.
This amount you dissolve in 20 ml water. You add the same amount of alcohol.

so is this how i do it?!
there will be 0.01 mol KOH in 20 ml. which is 0.5611 g KOH. so i dissolve 0.5611 g of KOH in 20 ml of water. and then add 20 ml of EtOH??!

[Nobby]

Yes correct.