10. Сумма коэффициентов в уравнении взаимодействия водорода с хлором:

The balanced chemical equation for the reaction between hydrogen (H2) and chlorine (Cl2) to form hydrogen chloride (HCl) is: H2 + Cl2 → 2HCl. The coefficients are 1 for H2, 1 for Cl2, and 2 for HCl. The sum of the coefficients is 1 + 1 + 2 = 4.