Download - 11 13 What Is A Chemical Equation
Launch: 11/13 Grab your binder and immediately take a seat!
1. How many of each atom are in the following molecules:
i. Br2 ii. H2S iii. CCl4
iv. H2SO4 v. C6H12O6
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What are chemical equations?
Mr. Heffner 11/13/09
A chemical equation is… a representation of a chemical reaction
2H2 + O2 2H2O
What are chemical equations?
Reactants Products
• The substances that are produced (made) • Right
• The substances that react • Left
A chemical equation is… a representation of a chemical reaction
2H2 + O2 2H2O
What are chemical equations?
Reaction Arrow
• “turns into”
• like an equals (=) sign
A chemical equation is… a representation of a chemical reaction
2H2 + O2 2H2O
What are chemical equations?
Coefficients Subscripts
• Comes after the atom
• Sub = below
• Comes before the compound
• distributed to all
Example 1. How many H atoms does 2H2 have?
multiply the subscript and the coefficient Coefficient = 2
Subscript = 2
2 X 2 = 4 hydrogen atoms
Example 2. How many H atoms does 2H2O have?
multiply the subscript and the coefficient Coefficient = 2
Subscript = 2
2 X 2 = 4 hydrogen atoms
Example 3. How many O atoms does 2H2O have?
multiply the subscript and the coefficient Coefficient = 2
Subscript = not there = 1
2 X 1 = 2 oxygen atoms
Example 4. How many O atoms does Mg(OH)2 have?
multiply the subscript and the coefficient Coefficient = not there = 1
Subscript = 2
1 X 2 = 2 oxygen atoms
Foldable Make foldable and define terms. Draw an
illustration if necessary. 1. Chemical equation 2. Reactants 3. Products
4. Coefficient 5. Subscript
6. Chemical reaction 7. Chemical bond 8. Molecule/compound
Practice Question Practice question handout
Exit Slip 1. What are chemical equations?
a. Representations of chemical reactions in which the reactants are listed to the left of a reaction arrow.
b. Representations of chemical bonds in which 2 valence electrons are depicted by a straight line
c. Representations of chemical reactions in which the. products are listed to the left of the reaction arrow.
d. A way to show how reaction arrows turn into reactants.
Exit Slip HC2H3O2 + NaHCO3 NaC2H3O2 + H2CO3
2. Which of the following correctly identifies all of the reactants in the above chemical equation.
a. NaC2H3O2
b. NaHCO3 c. NaC2H3O2 and HC2H3O2 d. HC2H3O2 and NaHCO3
Exit Slip 4Na + 4H2O 4NaOH + 2H2
3. Which of the following identifies the coefficient for H2O in the above chemical equation?
a. 1
b. 2 c. 4 d. 8
Exit Slip 4. How many C atoms are there in 3C2H4?
a. 2 b. 3
c. 5 d. 6
Exit Slip 5. Which of the following identifies the correct
number of atoms in 3H2SO4? a. 3 H atoms, 3 S atoms, 3 O atoms b. 2 H atoms, 1 S atom, 4 O atoms c. 6 H atoms, 3 S atoms, 4 O atoms
d. 6 H atoms, 3 S atom, 12 O atoms
Homework Finish practice question worksheet