How much water needs to be added to 15.0cm³ of 16.0M HNO3 in order to dilute it to a 2.5M solution

Answer 1

To dilute a concentrated solution to a lower molarity, we can use the formula:

M1V1 = M2V2

Where:
- M1 = initial molarity of the concentrated solution
- V1 = initial volume of the concentrated solution
- M2 = final molarity of the diluted solution
- V2 = final volume of the diluted solution

Given:
M1 = 16.0 M
V1 = 15.0 cm³
M2 = 2.5 M
V2 = unknown

Rearranging the formula to solve for V2:
V2 = (M1 * V1) / M2
V2 = (16.0 * 15.0) / 2.5
V2 = 96 cm³

Therefore, the total volume of the diluted solution needs to be 96 cm³. To find out how much water needs to be added, we subtract the initial volume of the concentrated solution from the total volume of the diluted solution:

Volume of water to be added = V2 - V1
Volume of water to be added = 96 cm³ - 15.0 cm³
Volume of water to be added = 81 cm³

Therefore, 81 cm³ of water needs to be added to 15.0 cm³ of 16.0 M HNO3 to dilute it to a 2.5 M solution.