Raina says : Glad chemistry is over, it's been 4 years. |
ryan5 says : FUCK THAT! Chemistry would have been better for me, if i had a decent teacher. Fair enough he was a good bloke n all, but man he could NOT teach. Physics, on other Hand, was AWESOME. But having said that, we only really scratched the surface of it. Edit: Before our holidays, we've started CARBON CHEMISTRY. . . and have forgotten some of what i learnt in the first lesson. |
miniradman says : citation :
hahaha I've been doing chemistry for about 9 months now. And it was only 2 days go that I was faced with the most difficult mathetical question of my entire life (even harder than maths B and anything I've come across in physics). I have to work out how much ethanol and water would go in to a 100ml solution with a 40mol ethanol :60mol water ratio... this might sound silly, but... does anyone know how to do this? |
miniradman says : hahaha I've been doing chemistry for about 9 months now. And it was only 2 days go that I was faced with the most difficult mathetical question of my entire life (even harder than maths B and anything I've come across in physics). I have to work out how much ethanol and water would go in to a 100ml solution with a 40mol ethanol :60mol water ratio... this might sound silly, but... does anyone know how to do this? |
Raina says : GOD, I hated those problems! Well, if I remember from college, water(H2O - 2 x H=1 and 1x O=16 is 18) weighs 18 g = 1 mol, density is 1 g = 1 ml. So for water 18 ml equals 1 mol. As for ethanol, I don't know the density and molecular Mass, so you should find out for yourself how much 1 mol ethanol = in ml... Now comes the part where I give bad advice , (since I'm positively convinced that chemistry is more cunning than to give 40% ethanol and 60% water) you then have 100 ml of solution, I'm absolutely sure there is another way, but i'd turn the 60 mol water into ml => 60 x 18 = 1080 ml then the the 40 mol ethanolin = x ml Then I'd use the x ml : 1080 ml ratio, you do the maths. Keep in mind that I almost failed this part (particularly the molarity, concentration solubility problems), and I might have said something stupid. |