unit 1: energy and matter lesson 9- 13

what are the elements never found by themselves in nature?

hydrogen - H2
fluorine -F2
iodine - I2
oxygen - 02
chlorine - Cl2
astatine - At2
nitrogen - N2
bromine - Br2
phosphorus - P4
sulphur - S8

what is an acid

compound that dissolves into water
forms a solution with a PH lower than 7
often contain hydrogen

what's a base

compound that dissolves into water,
forms a solution with a PH greater than 7
often contain hydroxide

properties of acids?

- taste sour
- aren't slippery
- PH less than 7
- Conductive

properties of bases?

-taste bitter
- slippery
- PH greater than 7
- conductive

how do bases react to indicators

- turns red litmus paper blue
- turns bromythal blue, blue
- is a bluish purple on universal indicator
- turns phenolphthalein pink

how do acids react to indicators

- turns blue litmus paper red
- is reddish pink on universal indicator
- turns bromythal blue, yellow
- (doesn't change) phenolphthalein remains colourless

what's the PH scale

measure of how basic or acidic a solution is, with 0 being extremely acidic, 14 extremely basic and 7 neutral

what's solubility?

ability of substance to dissolve in a certain solvent

what's a precipitate?

insoluble substances ( a solid)

what's dissociation?

the splitting of ions of an ionic compound in water

what happens to the crystal lattice structure in dissociation?

the lattice breaks apart and ions are free to move around in solvent

what can happen when two ionic compounds are placed in water?

a precipitate can form between the free ions of the compounds

what's an exothermic reaction

where there's a release of energy and energy is a product

what's an endothermic reaction?

where there's an absorption of energy and energy is a reactant

the breaking of bonds is _____________?

endothermic

the forming of new chemical bonds is_______________?

exothermic

what's the law of conservation of energy

energy can be converted into different forms, BUT the total energy of the universe stays the same

what's the law of conservation of mass

total mass of reacting ( reactants) substances is always equal to the mass of resulting (products) substances

what are the exceptions to the acid naming rules?

- organic compounds ( made up of carbon, hydrogen and oxygen mainly) - when writing formula don't have to start with hydrogen
- sulfur ( add "ur" before the "ic" or "ous" when classically naming)
- phosphorus ( add "or" before the "ic" or "ous" when classically naming)
chemical reaction

chemical reaction

a reaction that happens due to one or more substances changing to form different substances
- involves a change of energy (ex; temp change, emission of light, emission of sound, electrical energy)

chemical change

one or more substances changing to form different substances

how to know if a chemical change has occurred?

two of more of the evidences are apparent:
odour change, colour change, formation of a gas, formation of a precipitate, etc

what's the best indicator of chemical reaction

a new substance is formed and cannot be reversed

in chemical reactions what needs to happen to energy?

be either absorbed or released

in a chemical equation the arrow signifies what?

the direction a reaction is going from the reactants and the products

chemical equations consist of ?

3 parts... reactants, products and the arrow that separates them

what are reactants in a chemical equation?

the ingredients of a chemical reaction (always on the left side)

what are products in a chemical equation?

the chemicals formed FROM the reactants ( always on the right side)

what are the 13 common molecular compounds that don't follow the prefix rule?

propane
methane
ethane
ethanol ( ethyl alcohol)
acetic acid (ethanoic acid)
ammonia
glucose
sucrose
hydrogen sulfide
ozone
water
hydrogen peroxide

what are the properties of ionic compounds?

- transfer of electrons
- ionic bonds
-form crystal lattices
- usually solid at room temp
- conduct electricity in a solution (electrolytes)
- high melting and boiling point
- hard and brittle

what are the properties of molecular compounds?

- share electrons
- covalent bonds
- non metals bonded together
- s, l, g at room temp
- typically don't conduct electricity in solution ( nonelectrolytes)

propane's formula?

C3H8 (g)

what's propane's state

a gas

methane's formula?

CH4 (g)

methane state?

a gas

methanol formula?

CH3OH (l)

methanol state?

liquid

ethane formula?

C2H6 (g)

ethane state?

gas

ethanol formula? (ethyl alcohol)

C2H5OH (l)

acetic acid formula? (ethanoic acid)

CH3COOH (aq)

acetic acid state?

aqueous

what's propane's formula?

C3H8 (g)

ammonia formula?

NH3 (g)

ammonia state?

gas

glucose formula?

C6H12O6 (s)

glucose state?

solid

hydrogen sulfide formula?

H2S (g)

ozone's formula?

O3 (g)

sucrose formula?

C12H22O11 (s)

sucrose state?

solid

hydrogen peroxides formula?

H2O2 (L)

hydrogen peroxides state?

liquid

list the types of chemical reactions (7)

formation
decomposition
single replacement
double replacement
combustion
hydrocarbon combustion
neutralization

what happens in a formation reaction?

two elements reacting, form one compound
( A + B =AB)

what happens in a decomposition reaction?

one compound decomposing, forming two different elements
(AB > A + B)

what happens in a single replacement reaction?

one compound reacting with one element, forming one new compound and one new element
( AB + C = CB + A OR DE + F = DF + E)

what's a double replacement reaction?

two compounds reacting, forming two new compounds
( AB + CD = AD + CB)

what's a combustion reaction?

when any substance reacts with oxygen, can be thought of as burning
( ex: 4 Fe (S) + 3 02 (G) = 2 Fe2O3 (S) )
( ex 2: 2 Mg (s) + 02 (g) = 2MgO (s)

what's a hydrocarbon combustion?

one hydrocarbon reacting with oxygen gas, forming carbon dioxide and water
(CxHyOz + O2 = CO2 + H2O)

what's a neutralization reaction?

acid reacting with base, forming water and an ionic salt

what is nuclear notation?

aka isotope rotation, used to represent the different isotopes of an atom
- top number is the name of the element and molar mass ( ex: carbon 12- *12* C6)
- bottom number is number of protons (ex: carbon 12- 12C*6*

define insolubility

meaning substance can't dissolve into a solvent