Chemical Formulas and Equations
Study Jams Summary:
Elements are substances that cannot be broken down into anything smaller. Every element created is on the periodic table. When elements combine they make compounds. Chemical formulas show the elements that make up a compound. The subscripts in a chemical formula show us how many elements are in a compound.
Elements are substances that cannot be broken down into anything smaller. Every element created is on the periodic table. When elements combine they make compounds. Chemical formulas show the elements that make up a compound. The subscripts in a chemical formula show us how many elements are in a compound.
Part I: Chemical Equations
1. What is a chemical formula?
___A chemical formula is an expression that shows how many atoms are in a molecule of a substance._______________________________________________________
____________________________________________________________________________
2. What two things are indicated by a chemical formula?
___Subscripts (show atoms) and coefficients._________________________________________________________________________
____________________________________________________________________________
3. What two pieces of information are needed to determine the ratio of elements in a compound?
___The elements or compounds in a substance._________________________________________________________________________
____________________________________________________________________________
Part II: Interactive Tutorial on Balancing Equations
Follow the tutorial and answer the questions about the chemical equation below:
(NH4)2 Cr2O7 Cr2O3 + N2 + H2O
1. Name the four different types of atoms that are in the chemical equation.
___Hydrogen_______________________________ ___Oxygen_______________________________
___Chromium_______________________________ __Nitrogen______________________________
2. How many hydrogen atoms are in the reactant? _____________________________________
3. How many hydrogen atoms are in the product? _____________________________________
4. Explain how to determine if a chemical equation is balanced or unbalanced.
____If the reactant and product have the same number of atoms then they are balanced.________________________________________________________________________
____________________________________________________________________________
5. Is the above chemical equation balanced or unbalanced? ____Balanced________________________
6. Explain why or why not.
___They have the same number of atoms on each side._________________________________________________________________________
____________________________________________________________________________
1 Chemical Formulas and Equations
Matter and Energy
Part III: Anatomy of a Chemical Equation
1. What does a chemical equation represent?
___A chemical equation represents atoms in an expression._________________________________________________________________________
2. Name the three main parts of a chemical equation.
___Reactants_________________________________ ___Coefficients_________________________________
____Products________________________________
3. What does the arrow stand for in a chemical equation?
____Going from a reactant to product.________________________________________________________________________
4. Explain how the Law of Conservation of Matter applied in a chemical equation.
___No atoms are created or destroyed in a chemical equation._________________________________________________________________________
____________________________________________________________________________
5. How are coefficients (the numbers in front of the formulas) used to balance chemical
equations?
____________________________________________________________________________
___________________________________________________________________
1. What is a chemical formula?
___A chemical formula is an expression that shows how many atoms are in a molecule of a substance._______________________________________________________
____________________________________________________________________________
2. What two things are indicated by a chemical formula?
___Subscripts (show atoms) and coefficients._________________________________________________________________________
____________________________________________________________________________
3. What two pieces of information are needed to determine the ratio of elements in a compound?
___The elements or compounds in a substance._________________________________________________________________________
____________________________________________________________________________
Part II: Interactive Tutorial on Balancing Equations
Follow the tutorial and answer the questions about the chemical equation below:
(NH4)2 Cr2O7 Cr2O3 + N2 + H2O
1. Name the four different types of atoms that are in the chemical equation.
___Hydrogen_______________________________ ___Oxygen_______________________________
___Chromium_______________________________ __Nitrogen______________________________
2. How many hydrogen atoms are in the reactant? _____________________________________
3. How many hydrogen atoms are in the product? _____________________________________
4. Explain how to determine if a chemical equation is balanced or unbalanced.
____If the reactant and product have the same number of atoms then they are balanced.________________________________________________________________________
____________________________________________________________________________
5. Is the above chemical equation balanced or unbalanced? ____Balanced________________________
6. Explain why or why not.
___They have the same number of atoms on each side._________________________________________________________________________
____________________________________________________________________________
1 Chemical Formulas and Equations
Matter and Energy
Part III: Anatomy of a Chemical Equation
1. What does a chemical equation represent?
___A chemical equation represents atoms in an expression._________________________________________________________________________
2. Name the three main parts of a chemical equation.
___Reactants_________________________________ ___Coefficients_________________________________
____Products________________________________
3. What does the arrow stand for in a chemical equation?
____Going from a reactant to product.________________________________________________________________________
4. Explain how the Law of Conservation of Matter applied in a chemical equation.
___No atoms are created or destroyed in a chemical equation._________________________________________________________________________
____________________________________________________________________________
5. How are coefficients (the numbers in front of the formulas) used to balance chemical
equations?
____________________________________________________________________________
___________________________________________________________________