Question

colbalt chloride hexahyrate has a formula weight of 237.9g/mol. How much would you use to make 0.5 liter of a 0.3 M solution?

Answer 1

Answer –

We are given, molarity of colbalt chloride hexahyrate = 0.30 M

Volume = 0.5 L

First we need to calculate the moles of colbalt chloride hexahyrate

We know,

Molarity = moles / volume (L)

So, volume (L) = molarity * moles

                          = 0.30 M * 0.50 L

                           = 0.15 moles

Now we are calculated moles of colbalt chloride hexahyrate and we are given molar mass of colbalt chloride hexahyrate,

So mass of colbalt chloride hexahyrate = moles * molar mass

                                                               = 0.15 moles * 237.9 g/mol

                                                                = 35.7 g

So, 35.7 g of colbalt chloride hexahyrate need to use make 0.5 liter of a 0.3 M solution