Respuesta :

kenmyna
   The  molarity  of a  27%(v/v) aqueous  ethanol  solution  is 4.63 M

         calculation
convert  27%(v/v) to  fraction  = 27ml/100 ml

use  density to  convert  27ml  to grams =  27 ml  x0.79 g/ml = 21.33 g

find  the number  of moles  of C2H6O

moles = mass/molar mass of C2H6O(46.07 g/mol)

moles is therefore = 21.33 g /46.07 g/mol =0.463  moles

find the  molarity =   moles /volume in liters

volume in liter =  100 ml/1000 = 0.1 L

molarity  is therefore =  0.463 mole/0.1 L = 4.63  M
sebassandin

Answer:

[tex]M=4.63M[/tex]

Explanation:

Hello,

In this case, with the given by-volume percentage and considering the molarity as:

[tex]M=\frac{n_{Ethanol}}{V_{solution}}[/tex]

We assume the solution having 100 mL of volume in total, thus, the volume of ethanol is 27.0 mL, therefore, the moles:

[tex]n_{Ethanol}=27.0mL*\frac{0.790g}{1mL}*\frac{1mol}{46.07g}=0.463molEthanol[/tex]

Moreover, the volume of the solution in liters is:

[tex]V_{solution}=100mL*\frac{1L}{1000mL} =0.1L[/tex]

Finally, the molarity is:

[tex]M=\frac{0.463mol}{0.1L}\\ M=4.63M[/tex]

Best regards.

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