Chemistry question.

[woodie1]

I got this question in my email today. A friend sent me this-

"I have a problem---- I must maintain the acid concentration in a tank of liquid which consists of a mixture of hydrochloric acid and water. The proper concentration for my purposes is at a specific gravity of 1.09 --- the Hydrochloric acid which must be added is at 1.18 specific gravity

The tank holds 700 gal. of liquid--- because the concentration of the acid decreases with use and waste products build up that must be diluted, a certain amount of the old acid/ water mixture must be withdrawn from the tank and replaced with new acid---


volume in tank= 700 gal
target concentration = 1.09 specific gravity
concentration of pure acid = 1.18 specific gravity
concentration of spent acid= variable and must be determined experimentally before each adjustment

I need an mathematical statement (formula ) for calculating the amount of old acid ( unknown sp gr) to withdraw from the tank and replace with new acid ( 1.18 sp gr) in order to maintain the concentration of 1.09 sp gr in the tank while keeping the volume in the tank constant at 700 gal."


Any ideas? I sure could use some help.

TIA

 

You aren't making crystal meth or explosives are you ?

 

[woodie1]

No. This guy works at a plant that does chrome plating, I think.

I used to work at a place that had engineers who would know this but I can't remember any names to call so I thought the people here might be able to help.

 

[Mo0o]

i think its anthrax

 

[eakers]

conc.*volume(origional)=conc.*volume(desired)

solve.

is that what you want?

*kat. <-- not sure about specific gravity as she uses molarity.

 

[woodie1]

<< conc.*volume(origional)=conc.*volume(desired)

solve.

is that what you want?

*kat. <-- not sure about specific gravity as she uses molarity. >>



Huh?