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