What color does universal indicator show at pH 3?

What color does universal indicator show at pH 3?

• A. Red
• B. Orange
• C. Blue
• D. Purple

Answer: (A)

Universal indicator changes color as the acidity of a solution changes. The more acidic the solution (the lower the pH), the closer the color is to the red end of the spectrum. At pH 3, the solution is quite acidic, so the indicator sits in the red region. That’s why red is observed. If the pH were higher (closer to neutral or basic), you’d see colors moving toward orange, yellow, green, blue, and finally purple. Remember, this gives an approximate color corresponding to pH, not an exact value.

Universal indicator changes color as the acidity of a solution changes. The more acidic the solution (the lower the pH), the closer the color is to the red end of the spectrum. At pH 3, the solution is quite acidic, so the indicator sits in the red region. That’s why red is observed. If the pH were higher (closer to neutral or basic), you’d see colors moving toward orange, yellow, green, blue, and finally purple. Remember, this gives an approximate color corresponding to pH, not an exact value.