chemistry ch 7

small particles such as atoms, molecules, and ions are counted using this

mole (avogradros number)

what is avogadros number?

1 mole of any element =

avogadros number

what is used to convert moles to molecules

• combination reactions
• decomposition reactions
• single replacement reactions
• double replacement reactions
• combustion reactions

types of chemical reactions

two or more elements form one product

combination reaction

one substance splits into two or more simpler substances

decomposition reaction

one element takes the place of a different element in another reacting compound

single replacement

positive ions in the reactant compounds switch places.

double replacement

• a carbon-containing compound burns in oxygen gas to
  form carbon dioxide2(CO ) and water2(H O)
  • energy is released as a product in the form of heat

combustion reaction

the moles/atoms of each element in 1 mole of compound

the subscripts in a chemical formula show…

conversion factors

subscripts can be use to make…

loss of electrons (or H)

oxidation

The Gain of electrons (or the gain of Hydrogen)

reduction

• The minimum amount of energy required to "jumpstart" a reaction

• lower required energy of activation

activation energy

and catalysts

• mass of 1 mole of an element

• atomic mass expressed in grams

• 1 mole of C atoms= 12.01 g C atoms —> 1 mole C atoms/12.01 g C atoms

molar mass

molar mass conversion

what can be used to go from moles to grams or grams to moles

1) how to get from grams to moles

2) how to get from moles to atoms

3) how to get from atoms to molecules

1) heat

2) liquid

3) solid

4) dissolce in water

5) gas

what does a - indicate in chemical reactions

1) delta

2) l

3) s

4) aq

5) g

• no atoms lost or gained

in a balanced chemical equation…

two or more elements form one product

combination reaction

one substance splits into two
or more simpler substances

decomposition reaction

In a single replacement reaction, one element takes the
place of a different element in another reacting compound

A+ BC —> AC+ B

single replacement reaction

In a double replacement, the positive ions in the reactant
compounds switch places

double replacement reaction

• Co2 and H2O are always products

• energy released in form of heat

combustion reaction

mass of products

mass of reactants =

The rate of the forward reaction equals the rate of the reverse reaction.

What does it mean for a reaction to be at Equilibrium?

Le chateliers principal

2 moles of Fe + 3 moles S = 1 mole Fe2S3

how can you read this

convert the mass of one substance to another substance

given a balanced chemical equation we can …

1) conver mass of substance A to moles using molar mass of A

2) converting moles of substance A to substance B (using mole ratio of B to A)

3) convert moles of substance b into grams (molar mass)

how do you use a balanced chemical equation to go from mass a to mass b

1) collision- reactants must collide

2) orientation- reactants must align properly to break and form bonds

3) energy - collision must provide the energy of activation

What are the three conditions that must be present for a reaction to occur?

• heat is released

• the energy of the products is less than the energy of the reactants

• heat= product

exothermic reactions

• heat= absorbed

• energy of the products is greater than energy of reactants

• heat is a reactant (added)

endothermic reactions

• speed at which reactant is used up

• speed at which product forms

• increases when temperature rises —> reacting molecules move faster—> more collisions between molecules with energy of activation

• increases w conentration of reactants

reaction rate

• increase rate of reaction

• lowers energy of activation

• not used up during reaction

catalyst

• amount of atoms

• charges

in a formula, the subscript descibes … and the high script describes…

1) brackets

2) add charge

when drawing a lewis structure for a polyatomic ion dont forget ..

dipoles

Ionic and nonpolar covalent bonds will not have..

"Like Dissolves Like"

• Polar solvents dissolve polar or ionic solutes.

• Nonpolar solvents dissolve nonpolar solutes.