Methyl orange in an acidic solution is which color?

Methyl orange in an acidic solution is which color?

• A. Red
• B. Yellow
• C. Orange
• D. Pink

Answer: (A)

Color change of pH indicators depends on acidity; methyl orange is red in acidic solutions. It exists in two forms: a protonated red form in acidic conditions and a deprotonated yellow form in basic conditions. The acidic form is favored when there are many H+ ions, so the solution appears red. The transition range is about pH 3.1 to 4.4, with red in strongly acidic, orange in mid-range, and yellow in basic. So in an acidic solution, the observed color is red.

Color change of pH indicators depends on acidity; methyl orange is red in acidic solutions. It exists in two forms: a protonated red form in acidic conditions and a deprotonated yellow form in basic conditions. The acidic form is favored when there are many H+ ions, so the solution appears red. The transition range is about pH 3.1 to 4.4, with red in strongly acidic, orange in mid-range, and yellow in basic. So in an acidic solution, the observed color is red.