How much water should be added to 1 liter of 0.12N HCl to prepare exactly 0.1N HCl?

0.12N * 1 l.=0.12 mol

Total volume required for 0.1 mol = 1.2l
Thus volume of water to be added is 1.2-1.0 = 0.2 litre

To prepare 0.1N HCl from 0.12N HCl, the concentration needs to be diluted.

The formula for dilution is given by:

C1V1 = C2V2

Where:
C1 = initial concentration (0.12N)
V1 = initial volume (1 liter)
C2 = final concentration (0.1N)
V2 = final volume (unknown)

Let's substitute the values into the formula:

(0.12N)(1 liter) = (0.1N)(V2)

0.12 liter-N = 0.1N × V2

Now, we can solve for V2 (the final volume):

V2 = (0.12 liter-N) ÷ 0.1N

V2 = 1.2 liters

Therefore, to prepare exactly 0.1N HCl from 1 liter of 0.12N HCl, you need to add 0.2 liters (200 mL) of water.

To calculate how much water should be added to 1 liter of 0.12N HCl to prepare exactly 0.1N HCl, we need to use the concept of normality (N). Normality represents the concentration of a solution in terms of its chemical equivalents or reactive capacity.

The formula to calculate normality (N) is:

N = (Molarity * Number of Hydrogen Ions) / Basicity or Acidity

In the case of HCl, it is a strong acid and its basicity is 1. Therefore, we can simplify the formula to:

N = Molarity * Number of Hydrogen Ions

Now, let's calculate the number of moles of HCl in the 0.12N solution:

0.12N = Molarity * Number of Hydrogen Ions

Number of Hydrogen Ions = 0.12N / Molarity

Since the molarity of the 0.12N HCl solution is 0.12 M, we can substitute the values:

Number of Hydrogen Ions = 0.12N / 0.12 M

Number of Hydrogen Ions = 1 moles / 1 liters (as the molarity and normality of an acid are numerically the same)

Therefore, the number of moles of HCl in the 0.12N solution is 1 mole.

Now, we need to calculate the volume of the 0.1N HCl solution that is desired. The formula to calculate the volume of a solution is:

Volume = (Number of Moles) / (Molarity)

Volume = 1 mole / 0.1 M

Volume = 10 liters

Since we have 1 liter of the 0.12N HCl solution and we need to prepare 10 liters of the 0.1N HCl solution, we need to add 9 liters of water.

Therefore, to prepare exactly 0.1N HCl from 1 liter of 0.12N HCl, you should add 9 liters of water.