What is the mass of 20 moles of fluorine?

380g

Explanation:

Given parameters:

Number of moles of Fluorine  = 20moles

Unknown:

Mass of Fluorine  = ?

Solution:

The number of moles is the unit of quantifying the amount of particles in a substance.

 So;

      Mass of a substance  = number of moles  x molar mass

Molar mass of F = 19g/mol

 Now;

     Mass of F = 20 x 19 = 380g

i think 4.44 moles

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e