Types of Reactions
Which of the following is an example of an exothermic reaction?
A) Ice melting
B) A candle burning
C) Baking soda reacting with vinegar
D) Cooking an egg
A. A candle burning
Which of the following is a sign that a chemical reaction has occurred?
A) A new substance is formed
B) The substance freezes
C) The substance changes shape
D) The temperature remains the same
A. A new substance is formed
Which of the following is an example of a physical change?
A) Iron rusting
B) Water boiling
C) Wood burning
D) Baking a cake
B. Water boiling
02
What do you call the small number after the element symbol?
Subscript
What is the role of a catalyst in a chemical reaction?
A) It speeds up the reaction without being consumed
B) It absorbs energy from the reaction
C) It is consumed during the reaction
D) It creates a new product in the reaction
A. It speeds up the reaction without being consumed.
In an endothermic reaction, energy is __________.
A) Released into the surroundings
B) Absorbed from the surroundings
C) Neither released nor absorbed
D) Destroyed
B. Absorbed into the surroundings
What is the law that states that matter cannot be created or destroyed, only transformed?
What is the Law of Conservation of Mass
Is painting a wall yellow a chemical or physical change?
A physical change
2H202
What do you call the 2 in front of hydrogen?
a coefficient
What happens to the mass of the reactants in a chemical reaction?
A) It decreases
B) It increases
C) It stays the same
D) It disappears
C) It stays the same
Which type of reaction occurs when one element replaces another in a compound?
A) Synthesis reaction
B) Decomposition reaction
C) Single replacement reaction
D) Double replacement reaction
C. Single replacement reaction
What is produced when a chemical reaction releases heat or light?
What is energy.
"Is dissolving sugar in water a chemical or physical change?"
a physical change
What are the results of a chemical reaction called?
Which of the following is an example of a combustion reaction?
A) Two elements combine to form a compound
B) A substance reacts with oxygen to produce heat, light, carbon dioxide, and water
C) One element replaces another in a compound
D) A compound decomposes into simpler compounds
B) A substance reacts with oxygen to produce heat, light, carbon dioxide, and water
What happens in a synthesis reaction?
A) Two or more substances combine to form a new substance
B) A substance breaks down into simpler substances
C) One element replaces another in a compound
D) Two compounds exchange parts
A. Two or more substances combine to form a new substance.
What is the term for the process by which matter is transformed from one form to another, but the total mass remains the same?
Which of the following is not a sign of a chemical reaction?
A) Formation of a solid ( precipitate)
B) Formation of a gas (bubbles)
C). Increase in volume
D.) Rapid temperature change
C. Increase in volume
What is the term for a substance that is made up of two or more different types of atoms that are chemically bonded together?
A compound.
What is the Law of Conservation of Mass?
A) Mass is created during a chemical reaction
B) Mass is destroyed during a chemical reaction
C) The total mass of reactants equals the total mass of products
D) Mass changes during a reaction depending on the type of reaction
C) The total mass of reactants equals the total mass of products
What are the four major types of chemical reactions?
Combustion
Single replacement
Double replacement
Synthesis
What signs of a chemical reaction were present when we created elephant's toothpaste.
List 2 signs (think carefully about the role of the soap that formed bubbles, you may not use formation of bubbles)
* Change in temperature
* Production of a gas
Fill in the blank
A chemical change will always involve changes in chemical _ _ _ _ _.
bonds
A chemical formula simply describes the composition of a single compound by listing its elements and their quantities, while a chemical equation represents a complete chemical reaction, showing the reactants on the left side and the products on the right, using chemical formulas for each substance involved in the reaction
NaCl is the chemical formula for which substance?
salt