Orange juice has a pH of 4. Based on this lab, what color would you expect the paper test strip to be after it is dipped in a sample of orange juice?

The pH scale measures the hydrogen ion concentration in a solution to determine how acidic or basic it is. Pure water has a pH of 7, while solutions with lower pH numbers are more acidic and those with higher numbers are more basic.
Universal Indicator paper can be dipped into the solutions to get a read for the hydrogen ion concentration. The colors represented by the paper have a range that is similar to the colors of the rainbow. Red paper indicates a low pH, while a gradient of orange is not quite as acidic, but not yet balanced. Green or gray colors are indicative of neutral solutions, and blue to purple results express basic solutions.
Orange juice has a pH of 4, indicating it's more acidic than neutral. The Universal Indicator paper would turn a color ranging from orange to yellow depending on the particular brand of test strips. Packages of strips come with a color scale to match and give an exact indication of the pH level.
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