Red cabbage contains a water-soluble pigment. In a highly acidic solution, the pigment turns bright red, and in a moderately acidic solution, it turns pinkish. In a highly basic solution, the pigment turns yellow, and in a moderately basic solution, it turns bluish.

Question

A student makes a pH indicator from red cabbage that has a reddish-purple color with a pH of approximately 7. The student pours the same amount of the cabbage solution into each of four different beakers. He then adds a different household solution to each of the four beakers until a color change is obtained. His results are shown in the table below.

The student finds the following chart online from someone else’s cabbage pH indicator investigation.

Based on the information in the passage, which household solution has the highest pH?

a
window cleaner
b
lemon juice
c
drain cleaner
d
club soda

Answer 1

To determine which household solution has the highest pH based on the information provided about the red cabbage pH indicator, we can analyze the solutions typically associated with the household items listed:

• Window cleaner: Usually has a basic pH, often around 10-12.
• Lemon juice: Highly acidic, typically with a pH around 2.
• Drain cleaner: Very strongly basic, often with a pH above 12, sometimes up to 14.
• Club soda: Slightly acidic to neutral, usually around a pH of 5-6.

Given this information, drain cleaner (c) is likely to have the highest pH since it is very strongly basic compared to the other options listed. Thus, the answer is:

c drain cleaner.