Can you use methyl orange and phenolphthalein fro weak acid weak base titrations?
first of all remember that titr'n b/w weak acid and weak base is impossible.
weak acid*strong base-phenolphthalein
str acid*weak base-methyl orange
if both are strong can use both.
Methyl orange is a pH indicator frequently used in titrations. It is often chosen to be used in titrations because of its clear colour change. Because it changes colour at the pH of a mid-strength acid, it is usually used in titrations for acids. Unlike a universal indicator, methyl orange does not have a full spectrum of colour change, but has a sharper end point. Check out the Related Link for more details.
When you add an acid to an alkali it changes to a neutral which colour change would this show with an indicator?
It depends on the indicator and there are quite a few. Methyl Red, Methyl orange and Phenolphthalein are 3 such acid-base indicators. If phenolphthalein is used as the indicator and added to the base it would immediately turn red/pink. As acid is titrated in, the red/pink will disappear and go colorless.
acid base indicator or pH indicator Some examples of acid base indicators are: gentian violet, malachite green, thymol blue, methyl yellow, bromophenol blue, congo red, methyl orange, screened methyl orange, bromocresol green, methyl red, methyl purple, phenolphthalein, indigo carmine, hydrangea flowers, anthocyanin, litmus, red cabbage, and purple cauliflower.
There are various ways to test for an acid and an alkali. For acidic solution: Litmus paper/ litmus solution --> red Phenolphthalein --> colorless Methyl orange --> pink Universal Indicator (changes color according to the strength of acid) --> red to yellow. For alkaline solutions: Litmus paper/ litmus solution --> blue Phenolphthalein --> pink Methyl orange --> yellow Universal Indicator --> blue green to purple
Alkalinity is different from basicity, which is directly related to the pH. The higher the pH, the more basic the water. Like acidity, there are different ways to measure and report alkalinity; The first is to titrate the water with acid titrant to the phenolphthalein end point. This is called the phenolphthalein alkalinity. Since phenolphthalein changes color at pH~8.3, this corresponds to a pH where all the CO32- present would be protonated. Second, acid titration…
universal indicator, bromine can be used as an indicator for alkenes this will go from orange to colourless if in the presence of an alkene, phenolphthalein will turn from red to colourless if you add an acid to an alkali but not the other way around to test for an alkali that has been added to an acid use methyl orange which will turn from yellow to red.
Methyl orange is also known as p-dimethylamino-azobenzenesulfonic ACID. As stated on wikipedia, hence I would have to say that it is in fact an acid, interestingly, it is an acid that tells us whether a substance is an acid or alkali, by changing colour. It is known as an INDICATOR. In: Acid=Red. Alkali=Yellow. Neutral=Orange, thus the name methyl orange. HAHA. There you go. A decent answer. Hope this helps.
there are many types of acid base indicators - see chart at http://chemistry.about.com/library/weekly/aa112201a.htm Common indicators: Methyl orange - acid=red, base=orange Bromcresol green - acid=yellow, base=blue Bromphenol blue - acid=yellow, base=blue Phenolphthalein - acid=colorless, base=red it is also easy to use litmus paper - acid=red, base=blue
Because the end-points of these titrations have different pH values. A strong acid / strong base titration has an endpoint of pH 7, and an indicator that changes near 7 is useful. Phenolphthalein changes around pH 8.5 which is close enough for government work (so to speak). A strong acid - weak base titration will have an endpoint below 7, and so an indicator that changes over a range that is less than 7 should…
Acids burn and irritate the skin. They change; Litmus from blue to red Phenolphthalein from pink to colourless Methyl orange and methyl red from yellow to red They react with; Metals to give hydrogen gas Carbonates to give CO2 Alkali to give a salt and water Metal oxides to give a salt and water All have hydrogen in their formulas and they do need water or moisture to behave as an acid.