Question

For each of the solutions described below, determine the pH range for the solution using the information given and the indicator chart Solution A Indicator Used alizarin yellow Indicator color Yellow bromthymol blue yellow methyl violet violet Range bear the 21 less than 7.6 leathen lib really them 5.1 Gooher the 3.2 bromcresol green green methyl red red The pH range for solution A is 3.2 7.6 Solution B Indicator Used methyl red Indicator color yellow Range leroth 67 alizarin yellow R yellow phenol red red Teater R1 greater than 8.4 greater than 44 len the 9,3 methyl orange yellow thymolphthalein colorless The pH range for solution B is 1.1. Suppose you have done an analysis of some pond water for a friend. Using a pH meter, you determine the pH of the water to be 6.25. Which TWO indicators could you use to demonstrate to your friend that the pH is close to 6.257 List the indicators, the colors you would expect and the range you would show your friend using the two indicators. Use mothyl and to obtorn yellow for the expit teloge ir who has

Answer 1

7. From the pH indicator chart we can say that

Range of pH indicator:

Alizarin yellow R: 10.2 to 12

Bromothymol blue: 2.8 to 7.6

Bromocresol green: 3.8 to 5.4

Methyl orange: 3.1 to 4.4

Methyl red: 4.4 to 6.3

Methyl violet: 0.15 to 3.2

Phenol red: 6.8 to 8.4

Thymolphthalein: 9.3 to 10.5

From this data we can fill the table as:

Indicator color Ronge solution A Indicator used Indicator color Range . alizarin yellow R Yellow Less than 10-2 bromdhymol blue Yellow 2.8 to 7:6 Methyl violet violet 0.15 3.2 bromo cresol green goles Less than 3-8 Methyl red red Less than 44 . The pH range for solution A is 28 to 3-2. solution B Indicator usech. Methyl red Yellow 42-6-3 Alizarin yellow R Yellow Less thom 10.2 phenol red 6.8-8.4 methyl orenge yellow 31-4.4. thymolphthalein Colorless Less than 9.3 - The pH range for solution Bis 3.1-8.4. 8. Given pH of the water is 60.25. As the pt of the solution is 6.25, so the two indicators will be - - i) Methyl red as it's range is 4.4 to 6.3 S and it will change from Red to yellow color. ii) Resaurin as it's range is 3:8 to Gol ... and it will change from orange to violet. Red