Chapter 9 Study Guide – McGraw Hill Textbook
Section 9.1
Answer Key
T/F: A chemical reaction is present if a tomato smells rotten
t
T/F: A chemical reaction is present if a drinking glass breaks into smaller pieces
f
T/F: A chemical reaction is present when a piece of ice melts
f
T/F: A chemical reaction is present when a drain cleaner is mixed with water and the solution becomes warm
t
T/F: A chemical reaction is present when a candle burns
true if the reaction of the wax with the oxygen is making a new compound
T/F: A chemical reaction is present when green leaves turn yellow & red at the change of season
t
T/F: A chemical reaction is present when baking powder produces a gas that makes a cake rise
t
Balancing Chemical Equations
Section 9.1
reactant
A chemical substance that is present at the start of a chemical reaction
product
A substance produced in a chemical reaction
arrow in a chemical equation
Used to show what a chemical reaction yields (same as =); used to separate the reactants from the product. Left side items are reactants and right side items are the product.
plus sign in a chemical equation
used to separate the symbols in a chemical reaction on both sides of the arrow
(g); (aq); (l)
(g) = gas; (aq) = water; (l) = liquid. these symbols used to denote the state of the reactants and products in an accurate balanced chemical equation. Because water is abundant we only let water have the state (l). Everything that is dissolved in water has (aq) which means aqueous like aqua.
word equation for chemical reaction
used the name of the element(s) with all of the needed symbols. Ex: for water: Hydrogen(g) + Oxygen(l) > Water(aq)
skeletal equation for chemical reaction
a way of using the formulas to indicate the chemicals that were involved in the chemical reaction. “Mg + O2 MgO.” This skeleton equation shows that magnesium reacts with oxygen to form magnesium oxide.
balanced chemical equation
the number of the different atoms of elements in the reactants side is equal to that of the products side.
Section 9.2
Classifying Chemical Reactions
chemical synthesis
is a purposeful execution of chemical reactions to obtain a product, or several products. This happens by physical and chemical manipulations usually involving one or more reactions.
combustion
rapid chemical combination of a substance with oxygen, involving the production of heat and light.
decomposition
A chemical reaction that breaks down compounds into simpler products.
replacement
A reaction in which one element replaces another in a compound or when two elements in different compounds trade places
metal activity
Metals react by giving up electrons; the most active metals have the lowest ionization energy; cesium corner have the most reactive metals
halogen activity
Follows the order on the periodic table. Most reactive group of all elements
single-replacement
a chemical change in which one element replaces a second element in a compound
double-replacement
a chemical change that involves an exchange of positive ions between two compounds
Reactions in Aqueous Solutions
Section 9.3
aqueous solutions
solutions in which water is the solvent
reactions that form precipitates
Precipitation reactions occur when cations and anions in aqueous solution combine to form an insoluble ionic solid called a precipitate. Many variables determine this
reactions that form water
Special types of double displacement reactions that involve the reaction between an acid and base to form a salt and water.
reactions that form gases
generally an acid and metal compound that when rearranged one compound becomes a gas like CO2, HCN, H2