Table of Contents
- 1 Why is methyl orange used instead of phenolphthalein?
- 2 Why methyl orange is used as an indicator in titration of HCl and NaOH?
- 3 What happens when methyl orange is added to HCl?
- 4 Why can’t phenolphthalein be added to the titration mixture used in the determination of PKA?
- 5 When to use methyl orange or phenolphthalein as indicator in titration?
- 6 What happens if you titrate phenolphthalein at an acid pH?
Why is methyl orange used instead of phenolphthalein?
In the same way in the Titration of weak base versus strong acid there is a sudden change in the pH of 3.5 to 8.0,near the neutralisation point. So Phenolphthalein can’t be used since its pH range is 8.3 to 10.0. So Methyl orange is used as the indicator in this case.
Why is methyl orange used as an indicator for HCl?
Methyl orange is a pH indicator frequently used in titration because of its clear and distinct color variance at different pH values. Methyl orange shows red color in acidic medium and yellow color in basic medium. Because it changes color at the pKa of a mid strength acid, it is usually used in titration for acids.
Why phenolphthalein is not used in HCl titration?
In the same way in the Titration of weak base versus strong acid there is a sudden change in the pH of 3.5 to 8.0,near the neutralisation point. So Phenolphthalein can’t be used since its pH range is 8.3 to 10.0.
Why methyl orange is used as an indicator in titration of HCl and NaOH?
If a chemical indicator is used—methyl orange would be a good choice in this case—it changes from its basic to its acidic color. Titration of a weak base with a strong acid: A depiction of the pH change during a titration of HCl solution into an ammonia solution.
Why is methyl orange indicator used in HCl and Na2CO3 titration?
Purpose of Titration HCl gradually reduces the alkalinity of the solution until the pH is 7. Because the reaction between sodium carbonate and hydrochloric acid proceeds in two stages, you can use more than one indicator. Phenolphthalein is suitable for the first stage, and methyl orange is best for the second.
Why is Methyl Red used and not methyl orange is used as the indicator?
Soc., 1910, 97, 2477) concluded that g L as an indicator methyl red is greatly superior to methyl orange, as the colour curves show. It is quite true that the end-point with methyl red is sharper than with methyl orange when these indicators are simply tested in water with acid or alkali.
What happens when methyl orange is added to HCl?
When methyl orange is added to dilute hydrochloric acid, the color of the solution gets converted into red. When methyl orange is used as an indicator with acid, the color of the solution turns red. When methyl orange is used as an indicator with base, the color of the solution turns yellow.
Why methyl orange is used in titration of HCl and na2co3?
Methyl orange changes color in the pH range 3.0 to 4.4 when only one mole of $HCl$ reacts with one mole of sodium carbonate. Phenolphthalein changes color in the pH range of 8.0 to 9.8 when one mole of sodium carbonate is completely neutralized with two moles of $HCl$. Hence the correct option is (B).
When phenolphthalein is used as the indicator in a titration of an HCl?
When phenolphthalein is used as the indicator in a titration of an HCl solution with a solution of NaOH, the indicator undergoes a colour change from colourless to poink at the end point of the tiration.
Why can’t phenolphthalein be added to the titration mixture used in the determination of PKA?
Although the pH range over which phenolphthalein changes color is slightly greater than the pH at the equivalence point of the strong acid titration, the error will be negligible due to the slope of this portion of the titration curve.
Why is methyl orange used in carbonate titration and not phenolphthalein?
When titrating carbonates, which are weak acids, we typically use strong acids. When we use something like phenolphthalein as the end-point indicator, the color change corresponds to the first reaction. Methyl orange is a pH indicator frequently used in titrations because of its clear and distinct colour change.
What happens when methyl orange is added to hydrochloric acid?
When to use methyl orange or phenolphthalein as indicator in titration?
When you titrate a strong base ( such as NaOH) with a strong acid (such as HCl , it is acceptable to use either methyl orange or phenolphthalein as indicator. These two indicators have colour changes at different pH , – MO changes from red → yellow orange at pH 3.1 – 4.4 and phenolphthalein changes from colourless →purple at pH 8.2 – 9.8 .
Is methyl orange an acid or base or neutral?
In acidic medium, methyl orange is red, and when basic, it is yellow. At neutral pH, it is orange. However as a mid-strength acid, it is therefore it’s used usually in titration of acids. (Methyl orange is not typically used in strong acid-strong base titrations.)
What is the difference between phenolphthalein and Mo indicator?
These two indicators have colour changes at different pH , – MO changes from red → yellow orange at pH 3.1 – 4.4 and phenolphthalein changes from colourless →purple at pH 8.2 – 9.8 . On the face of it neither should be suitable for a titration where the equivalence point is at pH = 7.00.
What happens if you titrate phenolphthalein at an acid pH?
In addition, at an acid pH the metals will stay in solution, whereas if you used phenolphthalein (changes around pH 9) the solution will go murky with precipitated hydroxides (e.g. rust) and this will also affect the titration. 8 clever moves when you have $1,000 in the bank.