Answer:
Mass of ethane which is contained in 50 mL is 4.25 g
Step-by-step explanation:
13.9% by mass, means that in 100 g of solution, we have 13.9 grams of solute.
Density of solution is 0.611 g/mL
Volume of solution is 50 mL
Density = mass of solution / 50mL
0.611 g/mL . 50 mL = mass of solution → 30.55 g
Now, the rule of three.
In 100 grams of solution we have 13.9 grams of solute
30.5 grams of solution we have (30.55 . 13.9) / 100 = 4.25 g