Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: CraigM1279 on June 19, 2014, 10:56:43 PM
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Ok and so I took a chemistry in college and made an A but that was long ago....36 years to be exact and you truly loose what you don't use. I have some sodium hydroxide pellets and I want to make a 500ml 10% w/v solution in water and the same for a 30% w/v. Also I have some 20% hydrochloric acid and I want to reduce it to 500 ml 1% v/v . I need to know how much NaOH in terms of weight to add to what volume of water to make both the 10% and 30% solutions, also need the same for the HCL solution.
Thanks in Advance!!!!
**MOD Edit -- add a useful title**
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Forum rules require you show some work to receive help.
Please read forum rules.
Hint: 1 ml of water can be assumed to be 1 gram.
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LOL school has been out for a few weeks therefore that rules out any cheating. College classes still resume in the summer but this question is a bit remedial for that, and then there is the fact that I am 49 years old...HMMMMMM. I posted this on the High School forum because it is a High School level question. As far as showing my work ..well if I could do that then I would not need to ask the question on the first place. So the question stands and is anyone willing to help?
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You are missing the point.
We have plenty of students coming here and hoping someone will solve the problem for them. We can't know whether you are one of them, or not, so we treat everyone the same way. There are always places in the world where the school is not out.
Have you at least checked how these concentrations are defined? That's half of the success. And yes, that counts as an effort.
So the question stands and is anyone willing to help?
Only if you are willing to solve it.
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From GOOGLE
http://www.sciencecompany.com/Preparing-Chemical-Solutions-W174.aspx
Do you understand now?
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Some constructive hints.
For your first example you need specific gravity. Check in a tablebook or internet the value for 10%(30%) NaOH solution.
If you have this calculate from your given volume the mass and with the percentage you get the amount of solid NaOH.
The second one is more complicated because you asked for v/v. volume percent. This is not possible because no 100% HCl is existing in liquid, so far also no specific gravity. If you talking about w/v then its same way like with the NaOH.