Describing Chemical Reactions Flashcards
Give some examples of chemical reactions.
Fires burn, marshmallows toast to a golden brown, autumn leaves change colors, milk sours.
Chemical reaction
When one or more substances change into different substances
Word equation
A way of describing a chemical reaction using the names of reactants and products
Chemical equation
A way of describing a chemical reaction using the chemical formulas of reactants and products.
Reactants
The substances that are used up during the reaction
Products
The substances that are produced during the reaction
Chemical reactions can either…
Absorb or release energy
Where do you write “energy” in the equation if it was absorbed during a reaction?
If energy was absorbed it is written with the reactants in the equation.
Where is “energy” written in the equation if it was released?
If energy was released during the reaction it is written on the right side of the chemical equation.
What does the arrow indicate in an equation?
The arrow indicates the direction in which the chemical reaction is going. The arrow reads as “yields,” “forms,” or “produces.”
What substances to left of the arrow in an equation called?
They are called reactants
What are substances to the right of the arrow in an equation called?
They are called products
What does it mean if plus signs (+) are placed between the reactants?
It means that several reactants are involved. It also indicates that the reactants must be in contact with each other.
Why might plus signs (+) be placed between products?
If several products are formed then plus signs (+) are placed between products.
State Symbol
A symbol indicating the physical state of the chemical at room temperature ex. Solid (s), liquid (l), gas (g), or aqueous (aq).
