At the complete combustion of butane the carbon dioxide and water are formed.
2C₄H₁₀ + 13O₂ = 8CO₂ + 10H₂O
C₄H₁₀ ⇒ 4CO₂, 5H₂O ⇒ 13O ⇒ 6.5O₂
we use integer coefficients: 8CO₂, 10H₂O, 13O₂
The subscript is the amount of atoms in each molecule and the coefficient is the amount of molecules. there are 4 Hydrogen, 2 Sulfur, and 8 Oxygen in this particular substance.
When a system experiences a disturbance ( such as concentration, temperature, or pressure changes), it will respond to restore a new equilibrium state.