Four student (a), (b), (c) and (d) measured the pH values of water, lemon juice and sodium bicarbonate solution. What is the correct decreasing order of pH values?
What are the colour of pH paper , approximate pH value, nature of substance for the following solutions :-
Saliva (before meal ) , saliva (after meal) , lemon juice, colourless aerated drink , carrot juice , coffee, tomato juice , tap water, 1M NaOH , 1M HCl