Module 2 Flashcards
How can chemical reactions be identified?
Energy changes
What are the two energy changes?
Exothermic reaction & Endothermic reaction
What is an exothermic reaction?
An exothermic reaction is an energy change that RELEASES energy to their surroundings, causing the temperature to INCREASE. The PRODUCTS will have LESS chemical energy than the REACTANTS.
What is an endothermic reaction?
An endothermic reaction ABSORBS energy, causing the temperature to DROP. The products will have MORE chemical energy than the reactants.
What are reactants in a word equation?
The substances that react together
What are the products in a word equation?
The substances formed after the reaction
What are the state symbols in a word equation?
Solid = (s)
Liquid = (l)
Gas = (g)
Aqueous solution = (aq) (means dissolved in pani)
What is a fuel?
A substance that BURNS in OXYGEN to release ENERGY
What is the composition of air?
Nitrogen (79%) Oxygen (19%) Carbon Dioxide (0.04%) Argon (1.96%)
What is combustion?
Combustion is another name for a chemical reaction of a fuel burning (in oxygen)
What does it mean when a substance burns?
Reacts with oxygen
What is the test for oxygen?
Oxygen relights a glowing splint.
When carbon burns in oxygen, what does it produce?
Carbon dioxide (CO₂). Or Carbon monoxide, if INCOMPLETE COMBUSTION takes place.
What is the test for carbon dioxide?
Carbon dioxide turns lime water cloudy.
What is incomplete combustion?
When a lack of oxygen is produced.