Chapter 5 Test Flashcards
(34 cards)
Which one is NOT a chemical reaction? A. Wood burning B. Snow melting C. Fruit rotting D. Metal rusting
B. Snow melting
What are the signs a chemical reaction has occurred?
- change in temperature
- change in color
- formation of a gas (bubbles)
- a precipitate (solid) forms
What type of reaction is this the general equation for?
A+B → AB
Synthesis Reaction
What type of reaction is this the general equation for?
AB+ CD → AD + CB
Double Replacement Reaction
What type of reaction is this the general equation for?
AB → A + B
Decomposition Reaction
What type of reaction is this the general equation for?
fuel + oxygen → carbon dioxide + water
Combustion Reaction
What type of reaction is this the general equation for?
A+BC → B+ AC
Single Replacement Reaction
TRUE or FALSE?
Chemical reactions are necessary for life.
TRUE
TRUE or FALSE?
The same molecules must be present on both sides of a chemical equation.
FALSE
TRUE or FALSE?
A great concentration of reactants slows down a chemical reaction.
FALSE
TRUE or FALSE?
In a combustion reaction, a fuel combines quickly with oxygen.
TRUE
TRUE or FALSE?
A change in state is a common sign of a chemical reaction.
FALSE
What do all chemical reactions need to get started?
Energy
This type of reaction absorbs heat.
Endothermic
This type of reaction produces heat.
Exothermic
TRUE or FALSE?
The mass of the reactants must always equal the mass of the products in a chemical reaction.
TRUE
TRUE or FALSE?
The formation of water from hydrogen and oxygen is a reversible reaction.
TRUE
Why do chemical changes occur?
Because of chemical reactions.
What are the “ingredients” of a chemical reaction called?
Reactants
What are the substances that are made in a chemical reaction called?
Products
What does it mean when we say a chemical equation is balanced?
That it has the same number of atoms of each element on both sides of the reaction.
What is a coefficient? (with respect to a chemical equation)
The number that is placed in front of an element or a molecule.
How do we use coefficients when balancing chemical equations?
We can change them to get the number of atoms the same on both sides.
What is a subscript? (with regard to a chemical reaction)
The small number written at the bottom of an atom to indicate how many of that atom are in a molecule.
