Question

How many ethyne molecules are contained in 84.3 grams of ethyne (C2H2)?

Answer 1

(~26grams/mole) and Avogadros # (6.022x10^23) 84.3grams x 1mole/26grams x 6.022x10^23 molecules/mole = 1.95x10^24 molecules of C2H2

Answer 2

Step-by-step explanation:

According to the mole concept, there are
`6.022 * 10^(23)` atoms or molecules present in 1 mole.

As, it is given that mass of ethyne is 84.3 g. Hence, calculate its number of moles as follows.

No. of moles =
`\frac{mass}{\text{molar mass}}`

=
`(84.3 g)/(26.04 g/mol)`

= 3.24 mol

Therefore, calculate number of ethyne molecules as follows.

`3.24 mol * 6.022 * 10^(23)` atoms

=
`19.51 * 10^(23)` atoms

Thus, we can conclude that there are
`19.51 * 10^(23)` atoms in 84.3 grams of ethyne.