Aburning splint will burn more vigorously in pure oxygen than in air because a burning splint will burn more vigorously in pure oxygen than in air because nitrogen is a product of combustion and the system reaches equilibrium at a lower temperature oxygen is a catalyst for combustion oxygen is a reactant in combustion and concentration of oxygen is higher in pure oxygen than is in air oxygen is a product of combustion nitrogen is a reactant in combustion and its low concentration in pure oxygen catalyzes the combustion

A burning splint will burn more vigorously in pure oxygen than in air because oxygen is a reactant in combustion and concentration of oxygen is higher in pure oxygen than is in air.
Oxygen concentration in air is approximately 20%, the rest of are nitrogen, carbon dioxide and other gases. Oxygen is oxidazing reactant, that means oxygen give electrons in chemical reactions.

A burning splint will burn more vigorously in pure oxygen than in air because  oxygen is a reactant in combustion and concentration of oxygen is higher in pure oxygen than is in air.

Explanation:
                    As splints a basically made up of wood and is used in testing oxidizing gases like oxygen

                                     C  +  O₂  →  CO₂  

Also we know that pure oxygen contains 100% oxygen, while that %age of oxygen in air is only 20.95 %. Therefore, combustion reaction will be much faster in pure oxygen due to high concentration of oxygen.