Answer :
(7) When phenolphthalein is added to the solution of pH 10 (basic) then the color will be pink.
(8) When the litmus is blue in a solution that means the solution is basic in nature.
(9) The range of methyl orange is 3.2 - 4.4 (red-yellow).
The range of bromothymol blue is 6.0 - 7.6 (yellow-blue).
Explanation :
Part 7:
As the phenolphthalein is a synthetic indicator which is used to detect color change when an acid and a base is added to it. The neutral color of phenolphthalein is colorless.
Phenolphthalein indicator is colorless in acidic solution.
Phenolphthalein indicator gives pink color in basic solution.
When phenolphthalein is added to the solution of pH 10 (basic) then the color will be pink.
Part 8:
As the most common indicator used in the laboratory for testing acids and bases is litmus paper.
Litmus paper is of two types which are blue litmus and red litmus.
As the solution is acidic in nature then the litmus paper turns blue to red and as the solution is basic in nature then the litmus paper turns red to blue.
According to the question, when the litmus is blue in a solution that means the solution is basic in nature.
Part 9:
The range of methyl orange is 3.2 - 4.4 (red-yellow).
The range of bromothymol blue is 6.0 - 7.6 (yellow-blue).
