Question

A sample of soil is mixed with water and allowed to settle .The clear supernatant solution turns the pH paper yellowish - orange . Which of the following would change the colour of this pH paper to greenish- blue?
A. Lemon juice
B. Vinegar
C. Common salt
D. An antacid

Answer 1

Correct Answer - D
As pH p[aper turns greenish blue for weakly basic compund and antacids contain weak base like `Mg(OH)_(2)`. So an antacid would change the colour of this pH paper to greenish-blue . Other options (a) and (b) contain acids and option (c ) is a neutral salt.