Seek testing methods for concentrated hydrochloric acid
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As the title suggests, I need to know how to test concentrated hydrochloric acid. I would be extremely grateful if experts could give me some advice! Here are my thoughts: First, weigh a certain amount of concentrated hydrochloric acid using a weighing flask, then dissolve it in 100 ml of pure water. Use methyl orange as an indicator and proceed with titration using NaOH. I’m not sure if this method will work. My doubts are as follows: 1. Since concentrated hydrochloric acid is volatile, I’m not sure whether the mass measured in this way is accurate. 2. Is methyl orange an appropriate indicator? If not, please advise me on what indicator to use; it would be great if you could also provide instructions on how to prepare it.
The national standard specifies that hydrochloric acid should be added to a stoppered conical flask already containing water, and the difference in mass before and after addition is measured. Additionally, the indicator used for titration is methyl red. Here is a link for you: http://down.foodmate.net/standard/sort/3/11007.html You can take a closer look there.
1. Use a small iodine flask for weighing; it is actually sealed after the contents are added. 2. Use bromocresol green as an indicator
Refer to GB320-2006 \"Synthetic Hydrochloric Acid for Industrial Use\", available at http://bbs.hcbbs.com/viewthread.php?tid=26703&highlight=GB%2B320
Check the national standards; there are specific requirements in this regard
Do you mean reagent-grade hydrochloric acid (36-38%) when you talk about concentrated hydrochloric acid? To determine its concentration, we weigh about 3 grams of it in an iodine flask to which 15 ml of water has already been added; then we seal the flask with a water stopper, add a few drops of bromocresol green indicator, and titrate it using sodium hydroxide solution
Thank you all for your advice. What I need to measure is 36% hydrochloric acid, and your guidance has helped me get a better understanding of it!