I have 5ml of 0.07 mol/l Hcl I want to increase the molarity to 1 mol/l by adding minimum volume of hcl 31.2%

density 1.15 kg/l how much I have to add

To determine how much of the concentrated HCl solution you need to add to increase the molarity of the solution, we can use the equation:

M1V1 = M2V2

Where:
M1 = initial molarity = 0.07 mol/L
V1 = initial volume = 5 mL (which is equivalent to 0.005 L)
M2 = final molarity = 1 mol/L
V2 = final volume (unknown)

First, let's rearrange the equation to solve for V2:

V2 = (M1V1) / M2

Plugging in the values:

V2 = (0.07 mol/L * 0.005 L) / 1 mol/L

V2 = 0.00035 L (which is equivalent to 0.35 mL)

So, to increase the molarity of your 5 mL solution from 0.07 mol/L to 1 mol/L, you need to add 0.35 mL of the concentrated HCl solution.