Notes on the video
Students should notice the following:

	White ‘smoke’ appears in the glass tubing, and gets thicker. (At this point you could pause the video and ask what they think is causing the smoke).
	Prodding the bags makes more smoke (it is helping the two substances to mix)
	The bags crumple. (You could ask what this tells them: This is evidence that there is less and less gas in each of the bags, so there cannot be much/any ammonia or hydrogen chloride left or any other gas, as this would have kept the bags more inflated).
	Inside the glass tube is some white powder coating the sides.

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