Question

Octane C8H18 is an ingredient in gasoline. How many carbon atoms are in 20 kg of octane? help please

Answer 1

Octane is a hydrocarbon and an alkane with the chemical formula C 8 H 18, and the condensed structural formula CH 3 (CH 2) 6 CH 3.Octane has many structural isomers that differ by the amount and location of branching in the carbon chain. One of these isomers, 2,2,4-trimethylpentane (commonly called iso-octane) is used as one of the standard values in the octane rating scale.

Chemical formula: C₈H₁₈

Molar mass: 114.232 g·mol−1

Melting point: −57.1 to −56.6 °C; −70.9 to −69.8 °F; 216.0 to 216.6 K

Solubility in water: 0.007 mg dm−3 (at 20 °C)

Answer 2

Step-by-step explanation:

Octane is C8H18, carbon is C. Therefore, for every mol of C8H18 there will be 8 mols of carbon.

Convert 20 kg of octane to mols octane using molar mass of octane.

Molar Mass octane = (8*12.011)+(18*1.008)=114.23 g/mol, where 8 and 18 are the atoms in the molecule and 12.011 and 1.008 are the respective molar masses of carbon and hydrogen.

20kg C8H18 *1000g/kg * mol C8H18/114.23g C8H18 = 175.1 mols octane.

Now convert that number of mols to mols carbon:

175.1 mol C8H18 * (8 mol C/mol C8H18)=1400.8 mol C.

Now remember that a mol of any given atom=6.022*10^23 atoms.

So 1400.8 mol C=1400.8*(6.022*10^23) atoms C, which is equal to your final answer, 8.4*10^26 atoms. (round to 2 significant digits since the initial number given, 20, has 2 significant digits.)

The main thing you want to look for here is your conversion factors. Once you have those down it is simple algebra from there, so be sure to practice those!