Question

a student uses red litmus paper to test the ph value of different solutions. which would result in a color change of the litmus paper?
soap
vinegar
lemon juice
antifreeze

Explanation:

Red litmus paper changes color to blue in the presence of a basic solution. Soap is basic. Vinegar and lemon - juice are acidic and antifreeze is usually neutral or slightly acidic. So only soap can change the color of red litmus paper.

Answer:

A. soap