Physical or Chemical?
What is a process that produces chemical change (bonds broken and/or bonds formed/ title of chapter)?
A chemical reaction
Substances that are formed in a reaction
products
Energy released or given off
exothermic
The number of atoms in the reactants must equal the number of atoms in the products. What law?
What is law of conservation of mass?
Balancing of chemical equations by the grams
What is law conservstion of mass
What is changes in the substances apperance or phase of matter?
Physical change
The yields symbol always points
right
Temperature would decrease in the reaction and more energy in the products than the reactants
endothermic
The coefficient in front of a formula tells you the number of _________ of that element or substance.
molecules
N2 + 3 H2 -----> ___ NH3
2
The type of change when substances are dissolved
What is physical change?
The mass of a closed system reaction from the beginning to the end of the reaction does this since matter can't enter or leave
stays the same
Hydrogen and oxygen combine to from water
What is 2H2+ O2->2H2O+energy?
Like mathematical equations used to demonstrate a chemical reaction
What are chemical equations?
N2 + 3H2 --------> 2 NH3
What is produced when combining nitrogen and hydrogen?
What is ammonia (see Phet Balancing/demo sheet)
Change when a new substance is created/ combustion/ newspaper burning
What is a chemical change?
Balance the equation and identify the missing coefficient
4 Na + 02 ---> ___ Na2O
2
What is 2H2O -> 2H2 + O2? classify
decomposition
chemical name for water
dihydrogen monoxide
Atoms are not ____________ or _________ during a chemical reaction
Created ; destroyed
The substances that undergo a chemical change in a chemical reaction are called
reactants
Classify:
The reaction of hydrogen and oxygen to make water
synthesis
These type of reactions will always involve oxygen and iron Fe2O3
oxidation
classify the equation
AB + CD --------> AC + BD
What is double replacement
Balance the equation
__ H2O ----> __ H2 + __ O2
_2_ H2O ----> _2_ H2 + _1_ O2
or
_2_ H2O ----> _2_ H2 + __ O2