Describe how do you prepare 1.00 L of 0.646M HCl solution starting with 2.00M HCl?

Answer 1

This method assumes that a volumetric flask with capacity of 1.00 L is available, along with apparatus for measuring an arbitrarily chosen volume between 0 and 1 L to three significant digits of precision:

First calculate how many moles of HCl are needed for the volumetric flask. Since "M" means moles per liter, this value is 0.646 moles.

The calculate how large a volume of the 2.00 M solution is required to contain 0.646 moles of HCl. This value is (0.646 moles)/(2.00 moles/liter) or 0.323 liters.

Then transfer this amount of the 2.00 M solution into the volumetric flask and dilute to the capacity mark with distilled or otherwise purified water.