Chpt. 10, Chemical Reactions Flashcards Preview

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Flashcards in Chpt. 10, Chemical Reactions Deck (23):
1

indicators of a chemical reaction

the process spontaneously gives off heat (is exothermic) or spontaneously gets cold (is endothermic)

bubbles are spontaneously given off (like in vinegar and baking soda)

there may be a color change

the chemical properties are changed (like when you burn wood and it turns into ashes)

a precipitate is formed

2

indicators of a physical process

temperature change or bubbles will occur only if you do something specifically to make them happen

probably not a color change

chemical properties don't change, and a precipitate does not form

3

definition of a chemical equation

a complete list of the reactants (or reagents) and products of a reaction

4

exothermic reaction

a reaction that releases more energy that it takes in; to indicate that a reaction is exothermic, "triangleH = +" is written after the reaction

5

endothermic reaction

a reaction that requires more energy than it releases; to indicate that a reaction is endothermic, "triangleH = -" is written after the reaction

6

reactants/reagents

what you start with in a chemical reaction

7

products

what you end up with in a chemical reaction

8

conditions of a chemical reaction

these are things that are necessary in order for a chemical reaction to occur; when chemical reactions are written out, the reagents and products are connected by an arrow, and conditions of the reaction are placed over the arrow; they can be pretty much anything

when heat is required for the reaction, a triangle is placed over the arrow; when a specific temperature is required, that temperature is placed over the arrow; when cooling is required, a triangle followed by a "-" sign is placed over the arrow

9

state of matter indication

after every element or compound included in a reaction, the state of matter must be indicated; this is done with a one-letter subscript in parenthesis directly following the element or compound; the symbols are as follows:

(g) = gas
(l) = liquid
(s) = solid
(s) = solute (dissolved in water; not technically a state, but included)

10

balancing equations

Because reactions begin and end with the same number of atoms, the elements and compounds must be added in specific ratios. These ratios can be found by balancing chemical equations, which is the process of logically trying different values until the correct ratio for a given reaction is found.

11

the 6 types of chemical reactions

synthesis reaction
decomposition reaction
combustion reaction
single displacement reaction
double displacement reaction
acid-base reaction

12

determining reaction type

1. Does something containing C and H react with 02? If yes, it's a combustion reaction.
2. Do simple compounds make a complicated one? If yes, it's a synthesis reaction.
3. Does a complicated compound break down to make simpler ones? If yes, it's a decomposition reaction.
4. Are there any pure elements in the reaction? If yes, it's a single displacement reaction.
5. Is water formed in the reaction? If yes, it's an acid-base reaction. If no, it's a double displacement reaction.

13

synthesis reactions

occur when 2 chemicals combine to form 1 larger chemical

14

decomposition reactions

occurs when one chemical breaks down to form to or more smaller chemicals

15

combustion reactions

when something organic (something containing both hydrogen and carbon atoms) reacts with oxygen to form carbon dioxide gas and water vapor (plus lots of energy)

16

single displacement reactions

when the atoms of a pure element replace those of another element in a chemical compound; the pure element is usually, but not always, a metal

17

double displacement reactions

when the cations of two ionic compounds switch places; in order for a double displacement reaction to occur, both reactants must be soluble in water; one of the products will be soluble in water, and the other will be a solid

18

acid-base reactions (or neutralization reactions)

double displacement reactions in which water is formed

19

complete ionic equations

these types of equations show what happens to all of the ions when you put them in water; to write one, write the formulas of each dissolved ionic compound in the form of its separated ions, rather than as a chemical compound (because they're broken apart when they dissolve in water)

20

net ionic equations

these types of equations show only the ions that take part in any given ionic reaction; spectator ions are simply ignored

21

spectator ions

ions in water that are present at the time of an ionic reaction, but which do not actually participate in the reaction themselves

22

precipitate

a solid that’s formed when two liquids are mixed together;. this may show up as either chunks of solid, or more likely it will have a milky appearance due to the presence of very small solid flakes

23

solubility

some compounds' solubility is important to know when determining what type of reaction a given reaction is; to find the solubility of a chemical, use the solubility table provided on the back of periodic tables