Question

What is the mass, in g, of one molecule of ethane, C2H6?
A. 3.0 x 10-23
B. 5.0 x 10-23
C. 30
D. 1.8 x 1025​

Answer 1

Answer:

B. 5.0 x 10^(-23)

Explanation:

m= n × MM

where

m is mass

n is moles

MM is molecular mass

One molecule of a substance is 1/ 6.022 ×10^23 moles

The molecular mass of C2H6 is the sum of the atomic masses of each of the atoms present in the molecule. 2 carbon atoms + 6 hydrogen atoms. This gives

30.07.

So m= (1/(6.022×10^23)) × 30.07 = 5.0 ×10^(-23)

Answer 2

Mass of a substance can be calculated by using the formula:

Mass (m) = moles (n)  ×  Molar mass (M)

The correct answer is:

Option B. 5.0 × 10²³

Explanation for this is:

• Moles is used for measuring a large quantity of small entities like molecules and atoms.

• 1 molecule of substance = 1 / 6.022 ×10²³ moles

• The molecular mass of C₂H₆ ethane can be calculated by adding the mass of each atom present in it.

• Mass of 2 carbon atoms + Mass of 6 Hydrogen atoms

       = 2(12) + 6(1)

       = 24+6

       = 30

• So, mass (m) = 30 × 1/6.022 × 10²³

       = 5.0 × 10²³gm

Therefore, 5.0 × 10²³ gm is the mass of one molecule of ethane.

To learn more about mass, moles and molecular mass refer to the link:

https://brainly.com/question/24191825