Amount of acid = Volume of solution × Concentration of acid

Amount of acid = 4 liters × 30%

Amount of acid = 1.2 liters

Step 2: Determine the desired amount of acid in the 25% solution

Let x be the amount of water that needs to be added. The total volume of the solution after adding water will be (4 + x) liters.

Desired amount of acid = Total volume of solution × Desired concentration

Desired amount of acid = (4 + x) liters × 25%

Desired amount of acid = 0.25(4 + x) liters

Step 3: Set up an equation and solve for x

Since the amount of acid remains the same before and after adding water, we can set up the following equation:

Amount of acid in the 30% solution = Desired amount of acid in the 25% solution

1.2 liters = 0.25(4 + x) liters

Solving for x, we get:

1.2 liters = liter + 0.25x liters

0.25x liters = 1.2 liters - liter

0.25x = 0.2 liters

x = 0.8 liters

Therefore, Jorge needs to add 0.8 liters of water to make the 25% acid solution.