A technician measures 1.75 L of a standard solution of hydrochloric acid, HCI(aq), with a concentration of 9.00 mol/L. Determine the amount of water in litres that must be added to create a solution with a concentration of 2.50 mol/L

To determine the amount of water that must be added, we can use the formula:

C1V1 = C2V2

Where:
C1 = concentration of the initial solution (9.00 mol/L)
V1 = volume of the initial solution (1.75 L)
C2 = concentration of the final solution (2.50 mol/L)
V2 = volume of the final solution

Rearranging the formula to solve for V2:

V2 = (C1V1) / C2

V2 = (9.00 mol/L * 1.75 L) / 2.50 mol/L
V2 = 6.75 mol / 2.50 mol/L
V2 = 2.70 L

Therefore, 2.70 L of the final solution is needed. To find out how much water needs to be added, we subtract the initial volume of the acid solution from the final volume:

Amount of water = 2.70 L - 1.75 L
Amount of water = 0.95 L

So, 0.95 L of water must be added to create a solution with a concentration of 2.50 mol/L.