Question

A solution is made by dissolving 0.565 g of potassium nitrate in enough water to make up 250. mL of solution. What is the molarity of this solution?

Please explain and show work.

Answer 1

`\: \: \: \: \: \: \: \: \:`

Answer 2

Molar mass of Potassium Nitrate:-

`\\ \large\sf\longmapsto KNO_3`

`\\ \large\sf\longmapsto 39u+14u+3(16u)`

`\\ \large\sf\longmapsto 53u+48u`

`\\ \large\sf\longmapsto 101u`

`\\ \large\sf\longmapsto 101g/mol`

Now

`\boxed{\sf No\:of\:moles=(Given\:mass)/(Molar\:mass)}`

`\\ \large\sf\longmapsto No\:of\:moles=(0.565)/(101)`

`\\ \large\sf\longmapsto No\:of\:moles=0.005mol`

We know

`\boxed{\sf Molarity=(Moles\:of\:solute)/(Vol\:of\:Solution\:in\:L)}`

`\\ \large\sf\longmapsto Molarity=(0.005)/((250)/(1000)L)`

`\\ \large\sf\longmapsto Molarity=(0.005)/(0.250)`

`\\ \large\sf\longmapsto Molarity=0.02M`