Question

If 2.891g of Mg Cl2 is dissolved in enough water to make 300.0mL of solution what is the molarity of the magnesium chloride solution? The molecular mass of magnesium chloride 95.3g/mol and the density of the solution is 1.22g/mol.

Answer 1

Find the moles of magnesium chloride, divide by volume of solution.

\(\sf moles=\dfrac{mass}{Molar~Mass}\)

\(\sf Molarity=\dfrac{moles~of~solute}{L~of~solution}\)

Answer 2

Its asking for the molarity of magnesium chloride within the solution.

Answer 3

these are the possible answers to the problem
.5505 Mol
5.782 Mol
5.782 x 10^-3 Mol
6.703 x 10^-2 Mol

Also just noticed but is supposed to be 500mL not 300 mL.

Answer 4

what i posted above is how you find the molarity of MgCl2 in the solution.

Answer 5

i got 0.06067 M

Answer 6

it's pretty much D, 0.06067 M = 6.07*10^-2 M

that digit is likely an error

Answer 7

what are you dividing?
I did 500/1.22 and got 409.83 moles of solution.
I did 2.891/95.3 and got 0.303357 moles of MgCl2
I did 500/95.3 and got 5.2465

Answer 8

"density of the solution is 1.22g/mol." this is wrong

mol is not a unit of volume, its a typographical error and they mean mL, 1.22 g/mL

you dont need the density to solve the question though.

i found moles, first \(\sf moles=\dfrac{2.891~ g}{95.3~ g/mol}\)

then divided by the volume of solution (in liters)

\(\sf Molarity=\dfrac{(\dfrac{2.891~ g}{95.3~ g/mol})} {0.5~L}\)

Answer 9

ok I got it now. thank you for the explaination.