# How would you prepare 1.0 L of a o.500 M solution of potassium chloride?

Take a $1 L$ volumetric flask, and thru a funnel quantitatively transfer a $37.276 \cdot g$ mass of potassium salt. Fill the flask up to volume.
So all you have to do is accurately weigh the potassium chloride (of course if it's a bit out, you still know the accurate concentration). Potassium chloride has a molar mass of $74.5513 \cdot g \cdot m o {l}^{-} 1$; it is very (and easily) soluble in water, so you will have no difficulty in dissolving such a mass BEFORE you fill the flask to volume.