Complete combustion of 3.10 g of a hydrocarbon produced 9.90 g of CO2 and 3.55 g of H2O. What is the empirical formula for the hydrocarbon

C9H16

Explanation:

molar mass C = 12.011, H = 1.008, O = 15.999, CO2 = 44.01, H2O = 18.00

9.9g CO2 = 0.225 mol, 3.55 g H2O = 0.200 mol

long way

molecules CO2 = 1.355x10^23 —> atoms of C

molecules H2O = 1.204x10^23 —> molecules H2

C:H2 = 1.355/1.204 = 1.125. —> C9H16

short way

molar massesCO2:H2O = 0.225:0.2 = 9:8

–> C9H16

verify

molar mass C9H16 =124

3.1g = 0.025 mol

oxidise C9H16 + 13O2 —> 9CO2 + 8H2O

0.025 mol + 13*0.025 mol (0.35mol) —> 9*0.025 + 8*0.025 —> 0.0.225 + 0.2

vanderwaal's forces of attraction are the electrostatic intermolecular forces that exist in a molecule due to the temporary or permanent dipoles that are developed in a molecule. in , the major intermolecular forces are dipole-dipole interactions as the molecule is polar (bent structure). so the vanderwaal's forces of interaction in between molecules are the permanent dipole-dipole interactions that develop due to the dipole that exists in between the polar h - s bond. the positively charged hydrogen atom is attracted towards the negative end of the dipole that is sulfur of the adjacent molecule. therefore, these forces of attraction are relatively stronger than that of london dispersion forces that exist in non polar molecules.

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-