What is the mass percent of alcohol in a solution containing 62 mL of ethyl alcohol mixed into 200 mL of water? (Note: Density of ethyl alcohol = 0.8 g/mL; density of water = 1 g/mL.)

The mass percent of alcohol in a solution is 19.8 %

Explanation:

First of all we calculate the mass of each compound from the solution.

Solute → Ethyl alcohol

Solvent → Water

To determine the mass, we use density

Density = mass / volume → Mass = Density . volume

Mass of solute: 0.8 g/mL . 62 mL = 49.6 g

Mass of solvent:  1 g/mL . 200 mL = 200 g

Mass of solution = Solvent's mass + Solute 's mass

200 g + 49.6 g = 249.6 g

Mass percent of alcohol → (mass of alcohol / Total mass) . 100

(49.6 g / 249.6 g) . 100 = 19.8 %

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8