Question

How do you Calculate the number of liters of solution necessary to prepare 2.00 grams of Sodium bromide from a 0.10 m solution?

Answer 1

`~~0.198 L` if the solution is water

Explanation:

Given: 2.00 grams of Sodium Bromide (NaBr) from a 0.10 m solution.

Calculate the molar mass of NaBr:
`22.990 + 79.904 = 100.894 g/(mol)`

Calculate moles of NaBr:

`2.00 "g NaBr" xx (1 " mol NaBr")/(100.894" g NaBr") = 0.0198 " mol NaBr"`

molality `m = ("moles of solute")/("kg of solution")`

`0.10 = (0.0198 " mol NaBr")/(x" kg solution")`

`x" kg solution" = (0.0198 " mol NaBr")/0.10 = .198" kg solution"`

1 kg of water = 1 L of water because of the density of water

So, if the solution is water, the liters `~~0.198 L`