Exothermic vs. Endothermic
Endothermic reactions ______________ energy at the beginning of a chemical reaction
Absorb
The arrow in a chemical equation always points to what?
The products
How many atoms of Chlorine (Cl) are there?
4 Cl2
8
The masses of each side of a chemical equation should be ______
The same
Changes between states of matter are often which change?
Physical
Exothermic reactions ______________ energy at the end of a chemical reaction
Release
Reactants are what the chemical equations ________ with. AND Products are what the chemical equations ________ with.
Starts, Ends
How many atoms of Chlorine (Cl) and Sodium (Na) are there?
2Na + 2Cl --> 2NaCl
2 Na, 2 Cl
If the number of atoms on the reactant side is 12g, what should the number of atoms on the product side be?
12g
Bubbles forming is an example of what change?
Chemical Change
If two chemicals are mixed together and the temperature unexpectantly goes DOWN. What type of change occurred?
Endothermic
After a chemical reaction, the physical and chemical properties of the products will be _________________ than those of the reactants.
Different
How many elements are there in this equation?
P4O10+6H2O --> 4H3PO4
3
The amount of matter in an object is called ____________
Mass
Atoms in a chemical reaction are ____________ to make new substances
Rearranged
Two chemicals are mixed together, the test tube after the reaction caused it to be warm to the touch. What type of change occurred?
Exothermic
CH4 + 2O2 → CO2 + 2H2O What is the product?
CO2 and 2H2O
The ___________ in a chemical equation shows how many atoms of a specific element are present in a compound.
Subscript
The law of conservation of mass state that matter is never _________ or ________
Created, Destroyed
Which of these is NOT evidence that a chemical reaction has taken place?
Color change, Melting, Gas bubbles produced, Unexpected color change
Melting
What will happen to the rate of an exothermic reaction if the temperature is increased?
It will increase
6CO2 + 6H2O → 6O2 + C6H12O6 What is the reactant?
6CO2 and 6H2O
Sulfuric Acid (H2SO4) is made of (contains) ________, ________ and ___________. How many of each do you have?
Hydrogen, Sulfur, and Oxygen.
2,1,4
How much H2O should you have?
P4O10+6H2O --> 4H3PO4
24g 40g
16g
What are the two types of chemical reactions
Exothermic, Endothermic