Is having a pint glass of 100% alcohol mixed at a 40:60 ratio of alcohol:mixer the same as having a pint glass of 40% alcohol

Work it out!

If you have 100% alcohol mixed at a ratio of 40:60, it's like you put 40 mL of 100% alcohol in 60 mL of water. The total is 100 mL

And another one, where you put directly 100 mL of 40% alcohol.

Do you think they are the same?

That's why I'm asking, my mate says it's the same, I don't think it is.

Ok, let's see it this way:

Say that alcohol is represented by a tiny particle. In a 100% alcohol, say there are 100 particles of alcohol for 100 mL of that alcohol. (Similarly, 20% will mean 20 particles in 100 mL, 50% will mean 50 particles in 100 mL, etc)

In the first case, you are putting 40 mL of 100% alcohol in water, which gives 40 particles of alcohol, assuming the alcohol particles are evenly arranged in the liquid. Then you add 60 mL of water until you reach 100 mL, where no alcohol particle was added. How many alcohol particles are there? You initially put 40 particles, and none were added.

In the second case, you take 100 mL of 40% alcohol. Now, 40% alcohol means that there are 40 particles of alcohol in 100 mL of alcohol.

Now do you understand? :)

Reply if you still have problems.

I understand the mathematics of the question, I have from the start. But as it is alcohol does this mean it is the same strength, i.e. would they both have the same effect on the same person if both situations were exactly the same?

Thanks for replies by the way.

Well, assuming that the liquid used together with the alcohol (here, I used water) is the same, then yes, it would have the same effect.

By this, I mean that the company providing the 40% alcohol drink uses water to dilute the alcohol and the person preparing the pint of alcohol from the 100% alcohol uses water as well.

(Chemistry point of view)
Alcohol is a molecule and the number of molecules of alcohol only depends on the volume and concentration of the alcohol. If the volume is the same (1 pint) and you are using the same concentration (40%) the number of alcohol molecules will be the same, hence, same strength.

Thanks this is what I was looking for, thanks for the answer... although it seems I was wrong, tsk