Reaction basics
What is a reactant?
“a substance or molecule that participates in a chemical reaction”.
What is a synthesis reaction?
“a reaction in which two or more substances combine to form a new compound”.
What is a chemical equation?
“a representation of a chemical reaction that uses symbols to show the relationship between the reactants and the products”.
What is a catalyst?
“a substance that changes the rate of a chemical reaction without being consumed or changed significantly”.
What does the arrow "->" mean in an equation?
Yields, produces, or makes
What is a product?
“a substance that forms in a chemical reaction”.
What is a decomposition reaction?
“a reaction in which a single compound breaks down to form two or more simpler substances”.
Balance the equation: H + O2 -> H2O
4H + O2 -> 2H2O
What is an enzyme?
a type of protein that speeds up metabolic reactions in plants and animals without being permanently changed or destroyed”.
What is an exothermic reaction?
“a chemical reaction in which heat is released to the surroundings”.
What is an endothermic reaction?
“a chemical reaction that requires heat”.Absorbs heat and the temperature drops.
What is a combustion reaction?
“the oxidation reaction of an organic compound, in which heat is released”.
Balance the equation: K + Br2 -> KBr
2K + Br2 -> 2KBr
Identify which of the following is a chemical reaction:
a. melting ice c. rubbing a marker on paper
b. burning a candle d. rusting iron
b and d
Classifythe following reaction by type:
a. H2 +02 → H2O
Synthesis or combustion
What is chemical energy?
“the energy released when a chemical compound reacts to produce new compounds”.
What is a single displacement reaction?
“a reaction in which one element or radical takes the place of another element or radical in a compound”.
Balance the equation:H3PO4 -> H4P2O7 + H2O
4H3PO4 -> 2H4P2O7 + 2H2O
List four forms of energy that might be absorbed or released during a chemical reaction.
Heat, electricity, sound, and light can be absorbed or released during a chemical reaction.
Classify the following reaction by type:
Zn + 2HCl → ZnCl2 + H2
Single Displacement
List three signs that could make you think a chemical reaction might be taking place.
A change in temperature, fizzing, or a new substance with new properties being made.
What is a double displacement reaction?
“a reaction in which a gas, a solid precipitate, or a molecular compound forms from the apparent exchange of atoms or ions between two compounds”.
Balance the Equation: SiCl4 + H2O -> H4SiO4 + HCl
SiCl4 + 4H2O -> H4SiO4 + 4HCl
List five factors that may affect the rate of a chemical reaction.
Temperature, surface area, concentration, pressure, and molecular size may affect the rate of a chemical reaction.
Classify each of the following reactions by type:
c. S8 + 8O2 → 8SO2 + heat
d. NaCl + H2SO4 → Na2SO4 + HCl
c. combustion
d. double displacement