British Sign Language Glossaries of Curriculum Terms

BSL Chemistry Glossary - reaction - Laboratory video

I'm going to show you a good (example) of a reaction.

I have two reactants here - potassium iodide and lead nitrate. I'm going to pour them into this beaker and these reactants will react to form a new product - have a look ...

What a beautiful yellow colour! This is the product. These two reactants have reacted to create this product. The yellow liquid that has been made is lead iodide which is insoluble in water. Both of these reactants are solutions and both are soluble whereas this yellow liquid is insoluble.

We can remove the water by filtering it (filtration). There are two products in here - the colourless liquid that is coming out of the funnel is potassium nitrate; the yellow solid is lead iodide which because it's a solid won't pass through the filter paper (we call this a precipitate) - you can see them separating into this colourless liquid at the bottom and yellow solid at the top.

(2:50) These two reactants (on my left) have reacted together to make a product which we can separate using filtration. Next I'm going to take this beautiful yellow compound (lead iodide) and in the conical flask we have potassium nitrate which is still in solution whereas the lead iodide is a solid. This is why it's easy to separate them, because lead iodide can't pass through the filter whereas the potassium nitrate can.