My favorite is when a movie/TV show etc has a lab - especially a genetics lab such as I worked in - and every glass container has some vividly colored fluid in it. When I worked in a lab most of the glassware was empty - sterilized and ready for use - and of those which had any sort of fluid in them - the most colorful was growth media which was kinda beige. They do at least generally get pictures of DNA comparisons right.

While I haven't seen any videos of an entire bottle of gun powder set on fire - there is this video https://www.youtube.com/watch?v=fvlkeK7UF_Q which shows a small bit of gun powder lit up and it does burn quickly and brightly - but no explosion - of course to get any kind of pop you would need a container. What makes a firearm so effective is that the container in which the gunpowder is ignited is strong enough to trap ALL the combustion products inside the case / chamber / barrel behind the projectile. Any other container such as a plastic bottle is going to rupture or split open or melt long before you have enough o the combustion product produced to cause an explosion as you would expect to see with a high explosive.
This video is at least closer with a full pound - https://www.youtube.com/watch?v=K6hOWo2h-dg - but uses black powder taped into a cardboard tube - although not quite professional at least an attempt was made to contain the black powder during combustion.