Final answer:
NaN₃ is inorganic, C₄H₈, C₂H₂, and C₂H₅ are organic compounds.
Step-by-step explanation:
NaN₃ is classified as inorganic because it contains the inorganic element sodium.
C₄H₈ is classified as organic because it contains carbon, which is a key characteristic of organic compounds.
C₂H₂ is classified as organic because it contains carbon.
C₂H₅ is classified as organic because it contains carbon.