Answer is: X will turn blue and Y will turn red.
pH(liquid X) = 9; it is basic solution because pH is greater than 7.
pH(liquid Y) = 4; it is acidic solution, because pH is less that 7.
pH (potential of hydrogen) is a numeric scale used to specify the acidity or basicity an aqueous solution.
Neutral litmus paper turns red in acidic solutions and turns blue in alkaline solutions. At neutral pH, litmus paper does not change color.
