Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/26

Click to flip

26 Cards in this Set

  • Front
  • Back
chemical reaction
the process by which the atoms of one or more substances are rearranged to form different substances
evidence of chemical reactions
- temp. change (unexpected)
- release of energy (in the form of heat and light)
- absorbtion of heat
- color change
- odor
- gas bubbles
- formation of a solid
chemical equation
(balanced)
a statement that uses chemical formulas to show the identities and relative amounts of the substances involved in a chemical reaction
- shows how the law of conservation of mass is obeyed (or that the number of atoms of each reactant and each product is equal on both sides of the arrow)
coefficient
describes the lowest whole-number ratio of the amounts of all of the reactants and products
what are the 5 types of chemical reactions?
synthesis
combustion
decomposition
single-replacement
double-replacement
synthesis reaction
a chemical reaction in which 2 or more substances react to produce a single product
- when 2 ELEMENTS react, the reaction is ALWAYS a synthesis

A + B -- AB
- A and B can be elements or compounds, but AB will ALWAYS be a compound
combustion reaction
oxygen combines with a substance and releases energy in the form or heat or light

M(s) + 02(g) -- MOx(s)
- M is a metal

N(s) + 02(g) -- NOy(?)
- N is a nonmetal

CxHy(Oz) + 02(g) -- CO2(g)+ H20(g)
- (0z) = sometimes oxygen
decomposition reaction
a single compound breaks down into 2 or more new elements or new compounds

AB -- A + B
- AB is ALWAYS a compound
- A and B can be elements
or compounds

- often require an energy source to occur (heat, light etc.)

- involves the transfer of electrons from one atom to another
single-replacement reaction
the atoms of one element replace the atoms of another element in a compound

- use the activity series

M(s) + NX(aq) -- N(s) + MX(aq)
metal + compound(aq)-- replaced metal(s)or H2(g) + new compound(aq)

nonmetal + compound(aq)--replaced nonmetal + new compound(aq)

*M must be higher than N on the activity series for a reaction to occur

- involves the transfer of electrons from one atom to another
activity series
use in determining products of single-replacement reactions
- a specific metal can replace any metal listed BELOW it that is in a compound
- no reaction occurs when the metal is listed above it
- most active are on the top and least active on the bottom
double-replacement reaction
a replacement reaction which involves an exchange of ions between 2 compounds

MX(aq) + NY(aq)--MY + NX
- either MY or NX must be a
precipitate (insoluble), gas, or water

- the positive and negative ions of 2 compounds switch places
precipitate
a solid produced during a chemical reaction in a solution
- ALL double-replacement reactions produce either a precipitate, a gas, or water
oxidation-reduction reaction
also called a redox reaction

a reaction in which electrons are transferred from one atom of another atom
oxidation
the loss of electrons from atoms of a substance

there must be an accompanying process (reduction) the electrons lost by the oxidized substance must be accepted by another substance

Ex: Na-- Na+ + e-
reduction
the gain of electrons by atoms of a substance

Ex: Cl2 + 2e- -- 2Cl-
LEO GER
Loss of Electrons is Oxidation

Gain of Electrons is Reduction
oxidation number
(of an atom in an ionic compound)
the number of electrons lost or gained by the atom when it forms ions

oxidation number: +3, -3
ionic charge: 3+, 3-

increases when an atom is oxidized

decreases when an atom is reduced
oxidizing agent
the substance that oxidizes another substance by accepting its electrons

the substance that is being reduced
reducing agent
the substance that reduces another substance by losing electrons

supplies electrons to the substance getting reduced (gaining electrons)

it is oxidized b/c it loses electrons
oxidation number of an uncombined atom
= 0
oxidation number of a monatomic ion
= the change on the ion

Ex: Br-
oxidation number = -1
oxidation number of the more electronegative atom in a molecule or a complex ion
= the change that is the same as it would have if it were an ion
oxidation numbers of fluorine, oxygen, and hydrogen
In compounds:
F = -1 (same as ionic charge)

O = -2 (same as ionic charge)
EXCEPTION: +2 when bonded to F; -1 in peroxides

H = +1 (same as ionic charge)
EXCEPTION: -1 when bonded to less electronegative metals to form hydrides
oxidation numbers of metals of groups 1A and 2A and Al
form compounds in which the metal atom always has a positive oxidation number equal to its number of valence electrons
sum of oxidation numbers in a neutral compound
= 0
sum of the oxidation numbers in a polyatomic ion
= the charge of the ion