Question

Convert 26.02 x 1023 molecules of C2H8 to grams. Round your answer to the hundredths place.

Answer 1

No of molecules=26.02×10²³molecules

No of moles

• 26.02×10²³/6.023×10²³
• 4.3mol

Molar mass

• C2H8
• 2(12)+8(1)
• 24+8
• 32g/mol

Mass

• Moles×Molar mass
• 32(4.3)
• 137.6g

Answer 2

`\\ \tt{:}\longrightarrow No\:of\:moles=(Molecules)/(Avagadro\:no)`

`\\ \tt{:}\longrightarrow No\:of\:moles=(26.02* 10^(23))/(6.023* 10^(23))`

`\\ \tt{:}\longrightarrow No\:of\:moles=4.32mol`

• Molar mass of Ethane=32g/mol

We need the mass

`\\ \tt{:}\longrightarrow No\:of\:moles* molar\:mass`

`\\ \tt{:}\longrightarrow 32(4.32)`

`\\ \tt{:}\longrightarrow 138.24g`