The pale pink color of the titration solution at the end point will fade to colorless...

The pale pink color of the titration solution at the end point will fade to colorless after several minutes when exposed to the atmosphere. Account for this color change.

Expert Solution

1) The above mentioned observation seems to be happen during acid - base titration wherein a phenolphthalene indicator is being used to monitor end point.

2) Phenolphthalene indicator shows fait pink colour in slightly basic medium (this slightly basic medium neccesarily formed after slight excess addition of a base like NaOH beyound end point.

3) Further it's observed that this pale pink coloured solution when exposed to an environment for several minute fade to colourless. This reason for this can be the dissolution of CO2 which creates slighltly acidic envirnment following belowe equation,

CO₂ + H₂O -------------> H₂CO₃ <--------> H⁺ (aq.) + HCO₃^- (aq.)

These protons (H+) will neutralize excess HO- ions and makes sloution neutral as that of at end point of titration.

And in neutral medium phenolphthalene indicator will not exhibit any colour and hence solution fade to colourless.

=========================XXXXXXXXXXXXXXXXXXXX=========================

queen_honey_blossom answered 1 year ago

The half-equivalence point of a titration occurs half way to the end point, where half of...

The half-equivalence point of a titration occurs half way to the end point, where half of the analyte has reacted to form its conjugate, and the other half still remains unreacted. If 0.460 moles of a monoprotic weak acid (Ka = 1.0 × 10-5) is titrated with NaOH, what is the pH of the solution at the half-equivalence point? Calculate the [H ] and pH of a 0.000117 M iodoacetic acid solution. Keep in mind that the Ka of iodoacetic...

In mice the allele for blue coat color (B) pink coat color (b). The allele for...

In mice the allele for blue coat color (B) pink coat color (b). The allele for long tail (T) is dominant of the allele for short tail (t). 1) If alleles of the two genes Assort Independently, what types of gametes will BbTt mice produce? What is the expected frequency of each gamete among all gametes produced?

How do pH and Kf affect the end point of an EDTA titration?

Question 6 options: The color of the neutrophil's (?) is a very light pink or blue...

Question 6 options: The color of the neutrophil's (?) is a very light pink or blue and its nucleus has many (?) as it ages. Because it has the capacity to ingest and destroy certain intruders and or particles, it takes part in the process known as (?).

You wonder whether the proportion of children who have pink as their favorite color is different...

You wonder whether the proportion of children who have pink as their favorite color is different than the proportion of adults. You survey 100 children and 200 adults and find that 30% of children and 21% of adults have pink as their favorite color. Compute the value of the test statistic (in terms of children minus adults) that will allow you to test your hypothesis.

Flower color in buffalo clover is either white or some shade of pink to red. Pollen...

Flower color in buffalo clover is either white or some shade of pink to red. Pollen from a red individual was applied to white flowers in 1999. This seed was germinated in 2000 and four red plants were obtained in the progeny. These four red plants were allowed to self pollinate in summer 2000 to produce the next generation. Populations of progeny from each of the four plants were grown in the greenhouse in spring 2001 and the following data...

You have brown, pink, black, and white socks in a drawer (8 of each color). In...

You have brown, pink, black, and white socks in a drawer (8 of each color). In each of the following cases, what is the minimum number that you must take out to ensure that: a) You have a matching pair? b) You have two of different colors? c) You have at least 3 brown or 4 pink or 5 black or 7 white socks?

1- In the titration between potassium iodate and the sodium thiosulfate solution, if the titration is...

1- In the titration between potassium iodate and the sodium thiosulfate solution, if the titration is not performed immediately after the addition of the sulfuric acid, how would this likely affect the calculated concentration of your diluted sodium thiosulfate solution? 2- Why did the titrations performed need to be started immediately after adding the sulfuric acid? 3- A sample of bleach was analyzed as in this procedure. The only procedural difference is that the student weighed out the bleach solution...

Choose the statement that is true at the mid-point, or half-equivalence point, in the titration of...

Choose the statement that is true at the mid-point, or half-equivalence point, in the titration of a monoprotic weak acid and a strong base A)The moles of conjugate base and weak acid present in the solution are equal. B)The moles of strong acid and weak base present in the solution are equal. C)The moles of conjugate base and strong base present in the solution are equal. D)The moles of strong base and weak acid present in the solution are equal

What is special about the equivalence point in a titration?

Question