Question

describe how you make a 500ml solution contains the following compounds

1-5% glucose (MW=180)

2- .5M ethanol (MW= 46.07, Density= .789)

Answer 1

Solution:

A) Percent concentration =

(Mass of solute/Volume of solution) x 100

5 % glucose solution = (5 g /100 mL solution) x 100

Since, 100 mL solution requires 5 g glucose

Hence, 500 mL solution will required = 5 g x100 mL/ 500 mL

= 25 g

Thus, 25 g glucose is dissolved in water and make volume to 500 mL.

B) 0.5 M ethanol:

Molarity = Mass /Molar mass x volume in L

0.5 M = Mass / 46.07 gmol-1 x 0.500 L

Mass = 0.25 x 46.07 = 11.5175 g

Since,

Volume = Mass /Density

= 11.5175 g / 0.789 g mL-1 = 14.60 mL

Hence, 14.60 mL of ethanol is added in water and make the volume upto 500 mL.