Matter
Energy In Chemical Reactions
Types of Chemical Reactions
Chemical Equations
Mixed Bag
100
What is the difference between the formula CO and the symbol Co?
CO is the compound carbon monoxide and Co is the element cobalt.
100
What is required for a chemical bond to break?
Energy
100
In which kind of chemical reaction do two or more substances combine to form one new compound?
synthesis reaction
100
All molecules on the left side of the arrow in a chemical equation are called this.
What are reactants?
100
What is the force that holds atoms together called? a. a chemical solution b. a chemical mixture c. a chemical reaction d. a chemical bond
d. a chemical bond
200
Write the chemical formula for nitrogen dioxide.
NO2
200
Which of the following is NOT a sign of a chemical reaction? a. gas formation b. solid formation c. energy change d. state change
d. state change
200
In what type of reaction do elements in different compounds switch places?
Double-displacement reaction
200
This important scientific law states that during a chemical reaction, mass can never be created or destroyed.
What is the Law of Conservation of Mass?
200
If a chemical symbol in a chemical formula has no subscript, it means: a. the chemical symbol is written without any numbers. b. the element has no charge. c. the chemical is listed last in the formula. d. only one atom of the element is in the molecule.
d. only one atom of the element is in the molecule.
300
Which is the chemical name for the compound NaCl? a. sodium chlorine b. sodium chloride c. chlorine sodium d. sodium clorox
b. sodium chloride
300
What happens in an endothermic reaction? a. energy is destroyed b. energy is released c. energy is created d. energy is taken in
d. energy is taken in
300
Which of the following is an example of a chemical reaction? a. a tire losing air b. water boiling c. a solid forming in solution d. ice melting
c. a solid forming in solution
300
This number is the number of oxygen molecules in the following equation: 2H2 + O2 --> 2H2O
What is two?
300
How can you be sure a chemical reaction is happening? a. a solid dissolves b. a new substance is formed c. water turns to steam d. a mixture is made.
b. a new substance is formed
400
How many valence electrons should an element have to react with an element with seven valence electrons? a. one b. two c. three d. four
a. one
400
Which of the following shows an exothermic reaction? a. 2Na + Cl2 --> 2NaCl + energy b. 2H2 + O2 --> 2H20 c. 2H20 + energy --> 2H2 + O2 d. 6CO2 + 6H20 + energy --> C6H12O6 + 6O2
a. 2Na + Cl2 --> 2NaCl + energy
400
Which of the following chemical reactions illustrates a single-displacement reaction? a. 2H20 --> 2H2 + O2 b. 4H2 + 2O2 --> 2H2O c. 6CO2 + 6H20 + energy -->C6H12O6 + 6O2 d. 4KI +2Cl2 --> 4KCl + 2I2
d. 4KI +2Cl2 --> 4KCl + 2I2
400
This is the only type of number in a chemical equation that you can change.
What is a coefficient?
400
Which phrase describes what happens to atoms in a chemical reaction? a. sometimes lost, never rearranged b. sometimes lost, gained, or rearranged c. never lost or gained, just rearranged. d. lost or gained, never rearranged.
c. never lost or gained, just rearranged.
500
Atomic number on the periodic table refers to what? a. number of ways an element can be combined with other elements. b. the number of protons in each atom of an element. c. number of atoms in a cubic centimeter of an element. d. number of neutrons added to the number of protons found in an atom of an element.
b. number of protons in each atom of an element.
500
Use the graph to answer the question
Graph 1 represents an exothermic reaction because the total energy of the system decreases, so energy must be released in the reaction.
500
What is the difference between a synthesis reaction and a decomposition reaction?
In a synthesis reaction, two or more substances combine to form a single compound. A decomposition reaction is the reverse of a synthesis reaction because a single compound breaks down to form two or more simpler substances.
500
How many atoms are present in the formula CaCO3?
five
500
Sodium and chlorine can react chemically to form table salt. How does the mass of the table salt formed in this reaction compare to the mass of the sodium and chlorine before the reaction takes place? a. the mass of the table salt formed is less than the sodium and chlorine. b. the mass of the table salt formed is greater than the sodium and chlorine. c. the mass of the table salt formed is twice the mass of the sodium and chlorine. d. the mass of the table salt formed is the same as the mass of the sodium and chlorine.
d. the mass of the table salt formed is the same as the mass of the sodium and chlorine.
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