Videos

What triggers a chemical reaction?

Added Jun 09, 2017 •

Copy this URL:
Embed code:	<iframe class="edlio-embed-player" type="text/html" width="640" height="360" src="//colliervillehs.colliervilleschools.org/apps/embed/?v=150185" frameborder="0" allowfullscreen></iframe> Change dimensions

Show Transcript

you know how sometimes you go to bake a cake but you're bananas all gone rotten your utensils and rusted you trip and pour all of your baking soda into the vinegar jug and then your oven explodes my friend you and your chemical factions have fallen victim to enthalpy and entropy and boy are they forces to be reckoned with now your reactants are all products so what are these keywords and what's their big idea what start with enthalpy and increase or decrease of energy during a chemical reaction every has a certain amount of chemical potential energy stored within the bonds between its atoms chemicals with more energy or less stable and Thuss more likely to react let's visualize the energy flow in a reaction the combustion of hydrogen and oxygen by playing a round of crazy our goal is to get a ball the reactant of a small rise and down the other much steeper slope where the hill goes up we need to energy to the ball and where it goes down the ball releases energy into its surroundings the whole represents the product or result of the reaction when the reaction. Ends the ball is inside the hole and we have our product water this like when our oven exploded is an exothermic action meaning that the chemicals final energy is less than its starting energy and the difference has been added to the surrounding environment as light and heat we can also play out the opposite type of reaction an endothermic reaction where the final energy is greater than the starting energy that's what we were trying to play by baking our cake the added heat from the oven would change the chemical structure of the proteins in the eggs and various compounds in the butter and filthy as you might suspect exothermic reactions are more likely to happen than endothermic ones because they require less energy to occur but there's another independent factor that can make reactions happen entropy entropy measures of chemicals Randomness here's an enormous turn it up golf balls it's ordered structure means it has low entropy however when it collapses we have chaos everywhere balls bouncing high and why so much so that some even go over the hill this shift to instability or higher entropy can allow reactions to happen as with the golf balls in actual chemicals this transition from structure to disorder get some reactants past the hump and let them start a reaction you can see both enthalpy and entropy at play when you go to light a campfire to cook dinner your match as enough energy to activate the XO make reaction of combustion converting the high-energy combustible material in the wood to lower energy carbon dioxide and water entropy also increases and helps the reaction along because the neat organized log of wood is now converted into randomly moving water vapor and dioxide the energy shed by this exothermic reaction Powers the endothermic reaction of cooking your dinner bone appetit

Uploaded by Michelle Martin.

Videos

What triggers a chemical reaction?

More videos from Michelle Martin