"If you take a firecracker apart and light the powder, you’ll get a flash and a lot of smoke, but no bang. The explosion comes from the pressure building up in an enclosure."

True. But if you open enough firecrackers and put the powder in a small plastic container you will not get a bang but a buff and a fireball the size of a car.

Disclaimer: I am a chemist and a former very unwisely curious kid