need to make a 50% solution
Answers (1)
The first question in chemistry is always "What the heck are you talking about?" When you say "percent" you have to mention what is a percent of what, since the word only means "per hundred". A hundred what? It might be 100% of what is possible to dissolve, or a number of other things.
Second, you say "how much solution", and that is a mistake because you don't add solution, you add solvent.
Chemistry is the science of measuring things, and it is a lot like learning a new language.
1 ml
You need to be perfectly prepared in arithmetic to do well in chemistry. Get a ruler in your hands. Measure things until you start to understand how a ruler works. Measure some stuff and figure out where the center is. Say you measure a book and it's 7/8" thick. You look at your ruler and see that every eighth is divided into two sixteenths, so obviously half of 7/8" is going to be 7/16". If you write that out you have 1/2 x 7/8 = 7/16. And you notice that 1/2 is divided into 2/4 and then into 4/8 and so on, so you can convert anything to anything by multiplying all the numbers on top and then all the numbers on bottom.
Other rulers are divided into 10 and 100 parts. But an inch is still an inch, so anything on one ruler can be translated to the other ruler. A half inch on one ruler is 5/10 or 50/100 on the other. An eighth inch is just 12.5 marks when you have 100 marks per inch. A metric ruler divides an inch into 25.4 parts, so a half inch would be 12.7 of those parts. Pretty simple, isn't it? Practice this a bit and people will think you went to wizard school.
Percent is simply a ruler with 100 marks. The only confusion is trying to keep track of what the marks represent, since that changes from time to time.
i want to dilute a 100% compound, to half the strength. i have 1ml (100%), how much solvent do i need to use. to make it half the strength.