What volume of a 0.55m solution of potassium hydroxide can be made with 19.9 g of potassium hydroxide And please show me how to figure this out?

Answer 1

The first thing you need to do is convert your grams of potassium hydroxide into moles.

Potassium hydroxide has the formula KOH. The atomic weights are as follows:

K: 39.098 g/mol

O: 15.999 g/mol

H: 1.0079 g/mol

Add them together and you get a formula mass of 56.1049 g/mol. So now divide the mass by this value.

19.9g/56.1049 g/mol = 0.354 mol.

Molarity is moles divided by volume.

M=n/V

Since we are solving for volume we have to rearrange the equation.

M*V=n

V=n/M

So we divide the number of moles by the molarity to get the volume.

0.356 mol/0.55M =0.64 l.

So you would need 0.64 liters of water to obtain the desired concentration.