Which of the following is the correctly balanced equation for the incomplete combustion of heptene, c7h14? explain how you got the answer. 2c7h14+ 21o2→ 14co2+ 14h2o c7h14+ o2→ c7o2+ 7h2 c7h14+ 7o2→ 7co + 7h2o c7h14+ 14o → 7co + 7h2o

C₇H₁₄ + 7O₂ → 7CO + 7H₂O

Explanation:

For any equation to be balanced the number of (C, H, and O) atoms in the reactants side should be the same in the products side.The first choice is wrong because it is unbalanced equation that the reactants side has 22 O atoms and in the products side there is 14 O atoms.The second choice is wrong because the incomplete combustion of heptene results CO and/or CO₂ and H₂O.The third choice is the right answer that it has 7 atoms of C, 14 atoms of H, and 14 atoms of O in both reactants and products sides.The fourth choice is wrong because the combustion of heptene occurs in O₂ not in O.

Covalent bonds are the only intramolecular force listed.  All of the other ones are intermolecular forces.  Intramolecular forces only act between the atoms within the molecule while intermolecular forces are the forces that act in between the molecules.

Intermolecular forces: dipole-dipole, London dispersion, ion-dipole, and hydrogen bonding.  (Van der Waal forces I think refer to intermolecular forces in general or it could just refer to London dispersion forces.  I can't completely remember)
intramolecular forces: covalent bonds, ionic bonds, and metallic bonds.  

I hope this helps.  Let me know in the comments if anything is unclear.