Balancing chemical equations – Beginner

Balance the following equation. What is the number in front of HCl?

H₃PO₄ +HCl → PCl₅ + H₂O

Balance the following equation. What is the number in front of H₂?

CO + H₂ → C₈H₁₈ + H₂O

Balance the following equation. What is the number in front of SrO?

SrO + Al → Sr + Al₂O₃

Balance the following equation. What is the number in front of HCl?

TiCl₄ + H₂O → TiO₂ + HCl

Balance the following equation. What is the number in front of Mg?

Mg + N₂ → Mg₃N₂