Final answer:
The coefficient in the chemical equation C10H16 + 8Cl2 → 10C + 16HCl is the number '8' in front of the Cl2, indicating that eight molecules of chlorine gas are needed.
Step-by-step explanation:
The number that represents a coefficient in the chemical equation C10H16 + 8Cl2 → 10C + 16HCl is the number placed in front of a chemical formula to balance the equation. In this case, the numbers in front of C10H16 and Cl2 are coefficients. 8 is the coefficient in front of Cl2 indicating that eight molecules of chlorine gas react with one molecule of C10H16.
In chemical equations, coefficients are used to balance the number of each type of atom on both sides of the reaction to satisfy the Law of Conservation of Mass. A properly balanced equation will have the same number of each type of atom on both the reactant and product sides of the equation. In this example, the coefficients ensure that there are indeed 16 atoms of chlorine on both sides of the equation.