So I need to dilute 500ml of a 7% HCL solution down to 5%. How much water to add? I came up with 200ml but I’m not sure. Any help would be appreciated.
Help With Dilution Maths
So I need to dilute 500ml of a 7% HCL solution down to 5%. How much water to add? I came up with 200ml but I’m not sure. Any help would be appreciated.
you've been doing this for years
YEARS
Assuming these are volumes: 7% of 500 is 35ml.
35ml of how much is 5%?
I have no frickin idea
I that case hope you can repeat the school year to learn this.
Yeah well if I knew I wouldn’t be here asking. If it’s so fricking simple you could just tell me but like whatever I guess
I basically delivered the answer on a silver platter. You just need to pick it up. Take my words, make it into a formula and plug in the numbers. The stupid calculator won't teach you maths.
Also I’ve asked like everyone I know and no one knows. You act like this shot is common knowledge. Touch grass.
Did anyone of them graduate high school?
Not really, no. Think about what you want in the end. 35ml are 5%. How many ml are 100%?
175ml
I just showed you how
I know that you showed me and I said no because it's wrong. How can you tell that I saw your solution? I replied "no" to it.
35*5%=175ml
You need to be over 18 to post here
this is simple ass cross-multiplication
500/0.07x0.05=357mL
So I guess I’m using this calculator wrong?
yeah that calculator is wrong
Is it wrong or am I just using it wrong?
it's using volumetric concentration
you need to use molar mass concentration, you dumbass
It’s liquid though. Wouldn’t that be volume?
acids always use molar mass
volumetric is used for alcohol and stuff
Ok so then you must know the answer then. It’s a one time thing. I just need to figure this out one time and I can continue with my work. Yes I suck at math, I already know so I don’t need to hear it from anyone else.
So how come the bottle of acid I bought says 37% and nothing about molar mass?
If you're in genchem and they aren't teaching the unit conversions, someone needs to get anally ravaged.
(1/4)
(2/4)
(3/4)
(4/4)
Genchem? Lmao this has nothing to do with school you fricking geek. I’m making something with it.
Ok, neat. I hope you burn your house down, homosexual.
Chlorine dioxide isn’t flammable and neither is HCL. Yes I know that it has flammable gas already at higher concentrations. Why so hostile? Have sex.
You'll find a way to do it because you're moronic, so go on and impress us. I'm hostile because I attempted to help you, as a lot of others have, but you act like an entitled c**t in response. Don't ask for help next time.
No, I do appreciate the help. It was just banter, mate. No hard feelings. Those pics you posted make no sense to me but I appreciate the effort. Really I just need a definite answer because this is a mixture I have to make over and over for water purification. You put the 5% HCL into 27% sodium chlorite and it makes chlorine dioxide. This is a very abusive thread all around. No hard feeling man.
Also I know people in here are trying to help me but it seems like no one can agree on an answer and everyone is acting like it’s so easy. I think it’s 200 though but like what do I know?
Also not a single case of anyone burning anything making chlorine dioxide. I appreciate the thought though.
OP Sounds like a 7th grader. He can't find the solution with volumetric percentages. What makes you think that he's expected to solve this using molar mass?
So then it sounds like you know the answer. I’m using it to make something (CDS not drugs). I haven’t been in school for so long I forgot all this shit because I never use it. Yes I know I’m a brainlet. That’s why I’m here but you guys can’t even agree on an answer all the while everyone just comes in here to point out I’m a moron. Yes I already know I am. Why do you think I’m here asking you guys?
Are you fricking trolling me trying to get me to mix my shit wrong?
Forgot pic
Seems sensible to me
Ignore other answers and the calculator. If you found the answer you should be confident it's right, because it makes sense.
you have no business trying to answer this. Let me teach you something you absolute neophyte.
0.07(500)=0.05(500+x)
500+x=0.07(500)/0.05
x=0.07(500)/0.05-500=200ml
No you used it correctly.
>0.07(500)=0.05(500+x)
What abomination is this notation?
Holy fricking shit. I didnt believe the chemist brain. Now i do
what's the chemist brain? Do you have any funny pics of chemists being morons? I kinda dislike chemistry in general.
Literally getting confused by high school algebra
(not all chemists are moronic)
ah
well yeah obviously not all chemists are morons
but do you have funny pics of some chemists being morons?
lol this is blatantly wrong
Well is it frickin 200ml or not?
yes but after adding it, you cannot go back
Ok so that’s 2 of you saying it’s 200
Another says 357
Another says 175
There are multiple percentages in chemistry: https://en.m.wikipedia.org/wiki/Percentage_solution
This is why people specify which one they calculate beforehand.
The v/v doesnt care about molar mass, obviously.
The w/w does.
If we can believe anon above, w/w need to be used for acid solutions.
anon think about this
you have 5g in 100ml of solution, you add 100ml of water, now you have 5g in 200ml so 2.5% m/v
you have 5ml in 100ml of solution, you add 100ml of water, now you have 5ml in 200ml so 2.5% v/v
whether it is m/v or v/v doesn't matter here since we're diluting it, by multiplying the volume of solution by 2 you get a solution with half the concentration
It would be beneficial how many moles OP needs, because then he could make his solutions like a thinking man not a mechanical soulless drone, but asking whether it's m/v or v/v is not important here
c1 * V1 = c2 * V2
Black person you might as well be writing ancient Sanskrit. I have no idea how to execute that.
She's trans isn't she
Gtfo underage gay
Dude think about it.
500 ml is 7%
that means
1000 ml is 3.5%
that means
750 ml is 5.25%
that means
625 ml is 6,125%
That’s really not how it works though unfortunately
If you don't know this, you can't get to the solution
OP, can you tell us, how many moles of HCl are there in your 500ml of a 7% solution?
Nope
OP can you tell us the molecular weight of HCl?
Being a dumbfrick on this board should be a bannable offense.
v1c1=v2c2
what is the starting concentration c1? how much mg/ml is 7% HCl?
Stop doing what you are doing right now, you gonna kill someone.
which one? I want to help OP to get there in his own.
200ml is good
Based biochemists can do that purely mentally.
Doesn't even matter whether its m/v or v/v concentration. Going from 7 to 5 means diluting 5/7 times, i.e. the original solution is 5/7 of the final diluted one. 500ml is 5/7 => 700ml is 7/7.
Also 7% means 7 parts in 100ml, doesn't matter whether it's g or ml. 7 in 100 means 35 in 500. 5 in 100 means 5%, 35 in x means 5%. Knowing the multiplication table we know that
5*7=35
Hence 7*100 is the end volume
Start by drinking half the solution
I would dilute her maths, if you catch my drift
We want the end concentration to be 5%/7% = 5/7ths of it's current value, and hence we multiply the current volume of solvent by the reciprocal of this value
(7/5)*500 = 700,
and then to find the amount we need to add, we simply take the difference between our calculated end volume and our current volume
700 - 500 = 200.
Hence, we need to add 20 mL.
This all follows by basic properties of division/fractions and the fact that concentration of a substances is defined as the ratio S/T where S is the volume of the substance in question and T is the total volume of the solution. You are essentially solving the linear system
(5/7)F = S/T,
where F denotes the final concentration.