Answer: The molarity of the juice decreases.
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per kg of the solvent.
where,
n = moles of solute
= volume of solution in L
As volume of solution is inversely proportional to molarity, as water is added to juice, the volume of solution increases and thus the molarity decreases.
The moles remain fixed on adding water to juice.