On adding a few drops of universal indicator solution to three unknown colourless solutions `P,Q,` and `R` taken separately in three test-tubes shown in the diagrams, a student observed the changes in colour as green in solution `P` red in solution `Q` and violet in solution `R`.
The decreasing order of the pH of the three solutions is:

A student adds a few drops of the universal indicator solution to a dilute solution of sodium hydroencarbnonate taken in a test tube. Which of the following colour would he observe?

When a few drops of universal indicator were added to a dilute solution of HCl, it is observed that the colour of the solution changes from

When a few drops of universal indicator were added to a dilute solution of HCl, it is observed that the colour of the solution changes from

A student adds a few drops of the universal indicator to a solution of dilute hydrochloric acid in the way shown here. He would observe that the colour of the solution changes from colourless to:

A student took solution X in a test -tube and added a few drops of universal indicator to it. The solution turned blue. On addind another solution Y to this test tube drop wise, the colour of solution changed to green. When a yet another solution Z was added the solution turned yellow. Which of the following gives the correct conclusion of the student?