BALANCING EQUATION Flashcards
THE RULESSS
What do subscripts in a chemical formula describe?
The number of atoms in a molecule
Example: In H2O, the subscript ‘2’ indicates there are 2 hydrogen atoms.
What does the coefficient in a chemical equation represent?
The number of molecules
Example: In 2H2O, the coefficient ‘2’ indicates 2 molecules of water.
What are the three main parts of a chemical equation?
- Reactants
- Arrow (Chemical Reaction)
- Products
Which side of the equation contains the products?
The right side of the equation
Products are written after the arrow.
What are reactants in a chemical equation?
Elements or compounds that exist prior to a chemical reaction
Reactants are written before the arrow in the equation.
How many atoms of hydrogen are present in 2H2O?
4 atoms of hydrogen
Each H2O contains 2 hydrogen atoms, and there are 2 molecules.
What are products in a chemical equation?
New substances created by rearranging atoms after a chemical reaction
Products are written after the arrow.
What does the arrow in a chemical equation represent?
A chemical reaction
The arrow is read as ‘yields’.
What does the Law of Conservation of Mass state?
Matter (atoms) can neither be created nor destroyed; only rearranged.
How can you prove that matter is conserved in a chemical equation?
By showing that the number of atoms on both sides is equal.
What must be equal on both sides of a balanced chemical equation?
The number of the same type of atom
If unbalanced, change coefficients but not subscripts.
What is the subscript of oxygen in the reactants of the equation CH4 + 2O2?
2
The ‘2’ indicates two oxygen atoms in the O2 molecule.
What is the first step in balancing a chemical equation?
Take inventory of the elements and atoms on the product and reactant side.
What do you do if a chemical equation is unbalanced?
Change coefficients until it’s balanced.
Fill in the blank: Atoms are ______ in a chemical reaction.
rearranged
