Vocabulary
Balancing Equations
Rate of Reaction
Energy
Reaction Types
100
What is a product?
A substance that forms in a chemical reaction
100
_________________ uses symbols to represent a chemical reaction and shows the relationship between the reactants and products of a reaction.
Chemical Equation
100
List the 5 factors that affect the rate of reaction.
Temperature
Concentration
Surface Area
Catalysts
Nature of the Reactants
100
How does a chemical reaction occur?
Chemical Reactions occur when substances go through chemical changes to form new substances.
100
Define the term molar ratio and explain what this term is used for.
(Be sure to include an example of a molar ratio in order to receive full points.)
A balanced equation tells you the mole ratio or proportion of reactants to products in a chemical reaction.
Ex. For every 2 mol of Mg you need 1 mol of O
Mole ratios tell you the relative amounts of reactants and products.
Mole ratios can be converted to masses.
200
_______________ is a substance that participates in a chemical reaction.
Reactant
200
Equations are balanced by adding ______________ on front of one or more formulas.
Coefficients.
Balanced chemical equations account for the conservation of mass.
200
True or false: Most reactions go faster at lower temperatures.
False.
Most reactions go faster at higher temperatures.
When you increase temperature, the speed of particles increases which means there are more chances for particles to react.
200
____________ must be added to break bonds.
Energy
200
Define the term reaction types and list the 4 different types of reactions we discussed in class.
Patterns used to identify types of chemical reactions and predict products.
Four main types of Reactions:
Synthesis
Combustion
Decomposition
Replacement (Displacement)
300
_______________ is the energy in a chemical bond.
Chemical Energy
300
Balance the chemical equation below:
CH4 + Cl2 → CCl4 + HCl
CH4 + 4Cl2 → CCl4 + 4HCl
300
True or false: Cutting a potato up into pieces will take longer for it to boil than trying to boil the entire potato. When cut the surface area becomes smaller.
False.
Boiling a whole potato will take longer than boiling cut pieces. When cut the surface area becomes larger.
The same thing happens with reactions the smaller the pieces the faster the reaction.
300
True or false: a chemical reaction creates new atoms.
The reaction does not create new atoms it just rearranges them.
300
What type of reaction(s) is occurring in the example below? Be sure to define the reaction type(s) as well as name it/them.
A) H2CO3 → H2O + CO2
B) 2Na + Cl2 → 2NaC
A) Decomposition Reaction
AB → A + B
A chemical reaction in which a single compound breaks down into two or more elements or new compounds.
In this example reaction, carbonic acid decomposes to form water and carbon dioxide gas. Hence, this is the example of a decomposition reaction.
B) Synthesis Reaction
A chemical reaction in which two or more substances react to produce a single product.
A + B → AB
400
What is an exothermic reaction? Provide an example.
(Must include which has more energy in this reaction, the products or the reactants, in order to receive full points.)
Reactions that release energy are EXOTHERMIC.
A reaction in which energy is released to the surrounding area as heat.
The products have less energy than the reactants.
Ex: lighting a candle, starting a fire
400
Balance the chemical equation below:
Fe + O2 → Fe2O3
4Fe + 3O2 → 2Fe2O3
400
Explain the rate of reaction regarding concentration provide an example.
Higher concentrations of reactants react faster.
Just like with surface area, if you have a greater amount of small pieces the reaction will happen faster.
Ex. Setting up a bonfire, the more wood you put the reaction will speed up.
400
Explain the ways that energy can be transferred.
Energy can be transferred as a spark, electricity, sound or light.
When enough energy is transferred to separate atoms, bonds can break.
400
What type of reaction is occurring below? Be sure to define the reaction type as well as name it.
K + H20 → KOH + H2
Replacement Reaction
A + BC → B + AC
A chemical reaction in which an element or two is replaced by atoms of another element.
An example of a single replacement reaction occurs when potassium (K) reacts with water (H2O). A colorless solid compound named potassium hydroxide (KOH) forms, and hydrogen gas (H2) is set free.
500
What is an endothermic reaction? Provide an example.
(Must include which has more energy in this reaction, the products or the reactants, in order to receive full points.)
Reactions that absorb energy are ENDOTHERMIC.
A reaction in which more energy is required to break the bond.
The reactants have less energy than the products.
Ex: Photosynthesis is endothermic
500
Balance the chemical equation below:
Fe2O3 + C → Fe + CO2
500
Explain the rate of reaction regarding a catalyst and provide an example.
(Be sure to include your definition of a catalyst and explain the various components associated with a catalyst in the real world. You may also consider drawing a picture to support your answer.)
Catalyst- substance added to a reaction to increase the rate.
Ex. In real life Enzymes are catalyst for living things.
Enzymes attach themselves to a reactant called a substrate.
500
True or false: forming new bonds absorbs energy.
False.
Forming bonds releases energy.
When new bonds form energy is released. For example when gasoline burns, energy in the form of heat and light is released as a product.
500
What type of reaction is occurring below? Be sure to define the reaction type as well as name it.
Fuel + O2 → CO2 + H2O.
Combustion Reaction
The products of a complete combustion reaction include carbon dioxide (CO2) and water vapor (H2O). The reaction typically gives off heat and light as well.