A compound gives H+ and Cl– ions when dissolved in water. What will be the change in the colour of methyl orange if it is treated with above compound? Why?
Answers
Answer:
(a) Acids are : HCl and lemon juice because the pH is less than 7.
(b) Alkaline or basic solution turns phenolphthalein pink.
(c) Neutral solutions : Distilled water and NaCl.
(d) HCl is the strongest acid and NaOH is the strongest base.
Answer:
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. Unlike a universal indicator, methyl orange does not have a full spectrum of color change, but it has a sharp end point. In a solution becoming less acidic, methyl orange changes from red to orange and, finally, to yellow—with the reverse process occurring in a solution of increasing acidity.