2007-02-21 00:44:56 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
The term strong and weak acid refers to the dissociation of the acid and NOT the concentration. Strong acids are acids that dissociate 100%. Weak acids do not dissociate completely.
If you know the concentration of the acid and its valency (if it gives 1H+ or 2 H+ more per molecule), you can calculate the expected pH value for a strong acid. Then you can measure the pH and if you find that it is much higher than what you calculated, then it is a weak acid.
If you don't know anything about your acid, then you have to do a titration with a strong base, like a NaOH solution and follow the change of pH with a pH-meter as you add the base.
By plotting pH vs mL of base added you get a plot whose shape will tell you if it is a strong or a weak acid, if it is monoprotic or polyprotic and if it is weak it will allow you to calculate the dissociation constant Ka, which is the true measure of the strength of an acid .
2007-02-21 03:50:55 · answer #1 · answered by bellerophon 6 · 0⤊ 0⤋
Add alkaline solution and see how much is required to neutralize the acidic solution to neutral. Use an indicator to check for pH.
2007-02-21 08:55:47 · answer #2 · answered by Anonymous · 0⤊ 1⤋
Use universal indicator fluid - as this turns deeper and deeper red the stronger the acid.
Universal indicator also normally comes with a colour chart so you can precisely match the colour to the chart to get an accurate PH value.
2007-02-21 08:53:13 · answer #3 · answered by Doctor Q 6 · 0⤊ 1⤋