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 sample of soil is mixed with water and allowed to settle. The clear

1.	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?
Answer» Lemon juice Vinegar Common salt An antacid Solution :As pH paper turns greenish BLUE for weakly basic compound 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.