Question

How do we make a `1*L` volume of a solution that is `0.5*mol*L^-1` with respect to `HCl` from a solution that is `10.6*mol*L^-1` with respect to `HCl(aq)`?

Answer 1

Given proper attire, with conc. acid THE PRIMARY PRACTICAL CONSIDERATION IS `"ADD YOUR ACID TO WATER"` and NEVER `"VICE VERSA"`. We need approx. a `50*mL` volume of conc. acid.

Explanation:

And why so?

`"Because if you spit in acid, it spits back!"` I kid you not......

See [this older answer.](https://socratic.org/questions/how-should-you-dilute-concentrated-acid)

And other practical considerations. Wear a pair of SAFETY SPECTACLES to protect your mince pies; and wear a lab coat to protect your clothing......You should do this automatically in a lab (if you are a speccy, your prescription glasses are an adequate protection). Most chemists upon entering a lab will IMMEDIATELY put on a pair of safety spex from a tray, or put on the safety spec that they carry in their pocket. This is certainly a habit to develop.

And to make a `1*L` volume of `0.5*mol*L^-1` `HCl`; we use the relationship.....

`C_1V_1=C_2V_2`, and we solve for `V_1`.....

`V_1=(C_2V_2)/C_1=(0.5*mol*L^-1xx1*L)/(10.6*mol*L^-1)~=50*mL`.

And remember to add the `"WATER to YOUR ACID..............."`