Chapter 8 Chemical Equations and Reactions
How are a word equations and a formula equation alike? How do they differ from a chemical equation?
A word and formula equation both represent the reactants & products in a chemical reaction. They both are not balanced like in a chemical equation
General equation for single displacement reaction is
A+ BX > AX + B
General equation for synthesis reaction is
A+X > AX
General equation for decomposition reaction is
AX > A+X
General equation for double displacement reaction is
AX+ BY > AY + BX
The law of ________ must be satisfied for a chemical equation to be balanced.
Conservation of Mass
What are three observations that indicate a chemical change may be taking place?
Odor, forming of a precipitate, heat will be emitted, and a gas may be formed are signs of a chemical change
If metal X is lower than the metal Y in the activity series, then
Y will replace ions of X in solutions
A ______________ orders the elements by the ease with which they undergo certain chemical reactions
activity series
A _______________ uses symbols and formulas to represent the names and relative amounts of reactants and products in a chemical reaction
chemical equation
A small whole number that appears in front of a formula in a chemical equation is called
coefficients
To balance a chemical equation, it is permissible to adjust the
coefficients
A substance combines with oxygen, releasing a large amount of energy as heat and light, in a
combustion reaction
In a chemical equation, the symbol (aq) indicates that the substance is
dissolved in water
In a reaction, the ions of two compounds exchange places in aqueous solution to form two new compounds. This reaction is called a
double displacement reaction
The decomposition of a substance by an electric current is called
electrolysis
A ________ products is sometimes indicated by an arrow pointing upward
gaseous
The coefficients in a chemical equation
indicate the number of moles of each substance that react
The tendency for a replacement reaction to occur increases as the
interval between any two elements in the activity series increases.
The use of a double arrow in a chemical equation indicates that the reaction
is reversible
In a chemical equation, the symbol (l) indicates that the substance is
liquid
Oxides of active metals, such as CaO, react with water to form
metal hydroxides
The production of a slightly soluble solid compound in a double displacement reaction results in the formation of a
precipitate
The products re-form the original reactants in
reversible
