Question

the chemical formula for octane is: ch₃(ch₂)₆ch₃. calculate the molar mass of octane. round your answer to 1 decimal place. g·mol⁻¹

Explanation:

Step1: Identify the atoms and their counts

Octane ($CH_3(CH_2)_6CH_3$) has 8 carbon (C) atoms and 18 hydrogen (H) atoms.

Step2: Determine the atomic masses

The atomic mass of carbon is approximately 12.01 g/mol and hydrogen is approximately 1.01 g/mol.

Step3: Calculate the molar - mass contribution of carbon

The contribution of carbon to the molar mass is $12.01\times8 = 96.08$ g/mol.

Step4: Calculate the molar - mass contribution of hydrogen

The contribution of hydrogen to the molar mass is $1.01\times18=18.18$ g/mol.

Step5: Calculate the molar mass of octane

Add the contributions of carbon and hydrogen: $96.08 + 18.18=114.26$ g/mol.

Step6: Round the answer

Rounding 114.26 to 1 decimal place gives 114.3 g/mol.

Answer:

114.3 g/mol