Name: ________________________________
Class period: ___________
Elephant Toothpaste Chemistry
Illustrate the experiment below.
After
Before
The following reaction occurs:
H2O2
Hydrogen peroxide
H2O +
Water
O2
oxygen
1. Balance the following equation?
2. How many atoms are present in 2H2O2? _____________
3. How many molecules of 2H2O2 are present? __________
4. Does this reaction demonstrate a chemical or a physical reaction, what evidence supports your
answer? ____________________________________________________________________________
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5. Dows this reaction release or absorb heat? How do you know? ________________________________
____________________________________________________________________________________
6. Is the reaction an endothermic or exothermic reaction? Explain your choice: _____________________
___________________________________________________________________________________
7. Is the heat a reactant or a product? ___________________________________
8. Identify the reactant(s) and the products.
Reactants: ______________________________
Products: _______________________________
9. Explain what happened in the experiment:
__________________________________________________________________________________________
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Review 1 Matter
Concepts: Physical and chemical reaction, exothermic and endothermic reactions, chemical formula, coefficient, subscript,
1. Balanced Equation:
H2O2
H2O +
O2
Products located on ______________
Reactants located on _____________
Coefficient is ____________________________________________________________________________
Subscript _______________________________________________________________________________
Chemical Formula ________________________________________________________________________
Complete:
NaHCO3
Pb(NO3)2
Sodium –
Pb-
Hydrogen –
N-
Carbon –
O-
Oxygen -
Define the law of conservation of matter: ________________________________________________________
__________________________________________________________________________________________
2. Chemical and Physical reactions:
Explain the difference between chemical and physical reactions: _____________________________________
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Give examples that identify that a chemical reaction or a physical reaction has taken place:
Physical reaction
Chemical reaction
Identify the KEY difference between endo and exothermic reactions: _________________________________
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Identify if the following are exothermic or endothermic reactions:
Freezing water- ___________________________
Photosynthesis - ___________________________
Melting ice cubes- _________________________
Evaporation - ______________________________
Cooking an egg - ___________________________
Splitting a gas molecule- _____________________
Baking bread - _____________________________
Explosions- ________________________________
This will be graded. It is due MONDAY