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I have 60,000 LBS of a NaOH solution with a pH of 12.6. I need to be able to calculate the amount of 25% H2SO4 to add to bring the pH down to below 10. Is this possible to calculate?
mesa said:Someone on the board should check my numbers too! :)
mesa said:Small scale trial and error is also a good idea.
Borek said:...as we know nothing about accuracy of the initial numbers. They give a simple way of finding the order of magnitude type answer, but not the exact value.
MrSid said:I couldn't find a good density for 25% wt H2SO4
mesa said:for a pH of 10 you need 542.9mol so you can see a tiny change at this levels makes a huge difference in pH.
Just for numbers sake, that works out to about 18.865L of 25% H2SO4 by weight (about28.78M). Someone on the board should probably check these numbers too,
Borek said:1.1783 g/mL, 3.00M.
MrSid said:I couldn't find a good density for 25% wt H2SO4, but did find that baterry acid is typically a little more concentrated- it does appear that the molarity would not be as high as 28M since 100% H2SO4 is given as 18M.
The amount needed to bring down the pH depends on the initial pH level and the desired final pH level. You can use the formula: volume of acid = (initial pH - final pH) x (volume of solution) to calculate the amount of acid needed to lower the pH.
The pH scale is a measure of the acidity or basicity of a solution. It ranges from 0-14, with 7 being neutral. The lower the pH, the more acidic the solution is. Therefore, the lower the initial pH, the less amount of acid is needed to bring down the pH.
The choice of acid depends on the initial pH and the desired final pH. Strong acids, such as hydrochloric acid or sulfuric acid, are more effective at lowering the pH than weak acids, such as acetic acid. It is important to also consider the potential hazards and safety precautions when choosing an acid.
The accuracy of the calculated amount can be affected by factors such as the concentration and purity of the acid, the accuracy of the initial pH measurement, and any other substances present in the solution that may react with the acid. It is important to use precise measurements and perform multiple trials for more accurate results.
Theoretically, the pH can be lowered to 0, but in practicality, it is difficult to achieve such a low pH without extreme measures. It is also important to consider the potential hazards and safety precautions when working with highly acidic solutions. Generally, a pH of 1-2 is considered extremely acidic and should be handled with caution.