Question

There are 3 containers X, Y and Z. X contains
10ml of water and Z contains 10 ml of milk. Y
contains 5ml of milk (same as in container Z)
mixed with 5 ml of water. All 3 containers have
pH value of 6.5. P amount of Acetic acid is
added to container X, Q amount to Y and R
amount to Z. Such that the final pH value in
each container is 5.5. Then which of the
following is true?
(1)P<Q<R
(2) P<R=Q
(3) P = Q = R
(4) P<R<Q​

Answer 1

Answer:

P < Q < R

Explanation:

Answer 2

The correct option is (4) P<R<Q.

• When P amount of acetic acid is added to container X the acetate ion reacts with the proton of water so, its acidity rapidly decreases. Thus to keep the 5.5 pH of the container we have to add a small amount of acetic acid.
• When R amount of acetic acid is added to container Z which contain milk, the acidity decreases. Thus to keep the 5.5 pH of the container we have to add a higher amount of acetic acid.
• When Q is added to a container Y containing milk and water, the pH decreases slowly. So, a larger amount of acetic acid is added.