chem 20
what is an acid?
sour chemical that turns blue litmus paper red
what is an indicator?
chemical that changes color when certain substances are added
what is a chemical formula?
a shorthand way of writing the name of a compound; for example, H2O stands for water
what is hydrogen gas?
a gas that is given off when acids wear away metal
when can you taste or feel an acid?
when you know the substance is not harmful
example of an indicator?
litmus paper, comes in red and blue
what do acids do to blue litmus paper?
turn it red
what do acids do to red litmus paper
nothing
what do acids do to metals?
wear them away
can dry acids be tested to see properties?
no
fruit that contains acid
lemon
how can you tell that the gas is hydrogen?
makes a pop noisee
what acid do citrus fruits have
citric acid
what acid does milk have
lactic acid
what acid does vinegar have
acetic acid
does aspirin have acid?
yes
what acid treats a burn or can be used as eyewash?
boric acid
what acid is in car batteries?
sulfuric acid
what acid does your stomach make?
hydrochloric acid
what element in its special form do acids have?
hydrogen (h+)
what is a base?
bitter chemical that turns red litmus paper blue
what is phenolphthalein?
an indicator that turns a deep pink color when a base is added
how do acids and bases act?
opposite to each other
what do bases that are not harmful taste like?
bitter
what does a harmless base feel like?
slippery
what do bases do to red litmus paper
turn it blue
what do bases do to blue litmus paper
nothing
what does phenolphthalein do in acids
stays clear
do bases wear away metal
no
can dry bases show the properties?
no
are bases all the same strength?
no
what special groups of elements do bases have
special groups of oxygen and hydrogen atoms called hydroxides (oh-)
what base is used to clean?
ammonia water
what base is used on clogged drains?
lye
what base is used to make soap?
lye
what base emptys digestive tract?
milk of magnesia
what base is used to make fertilizers
ammonium hydroxide
what is an element
pure substances (made of one type of atom) made of atoms, atomic number determines element type
3 major ways periodic table is arranged
metals non metals metalloids
periods (rows) groups (columns)
atomic number
top left of element
atomic number
top right element
average atomic mass
periods
seven, elements have same # of energy levels
groups
eighteen, similar properties in same group
main groups
1- alkali metals
2- alkaline earth metals
16- chalcogens
17- halogens
18- noble/inert gases
properties of mmnm
metals- left, conductor, malleable lustre solid except hg
nm- right bad conductor brittle dull
metalloids- staircase, some m some nm
staircase (8)
B, Si, Ge, As, Sb, Te, Po, At
remember subatomic particle stuff
... -1 0 +1 nucleus nucleus energy shell
how to find neutrons
top left - top right (m-p)
explain bohr diagrams
288 put #p #n in middle
stable
full valence shell
ion
charged particle formed by losing/gaining e- to become stable
how to tell reactivity
closer to one in either direction is higher
how to tell if more likely to lose gain e-
whatever the charge is- to get stable
why is hydrogen special
it can act like a metal or nm depending on who its with, equally likely to lose or gain e
what is the noble gas exception
helium, full at two
how to do lewis dot
put valence e
what charge do atoms have
neutral, same # of p and e
what is a compound
contains 2 or more dif elements, neutral overall
ionic compounds
made of cations (+ metal) and anions (-nonmetal), ionic bond (opposites attract), formula is lowest possible ratio
molecular (covalent) compounds
2 nonmetals only, share e-, formula states # of each atom in compound so not ratio, difficult to predict
how to do lewis dot to form ionic compounds
move electrons from metal to nonmetal, draw charges with each element, write chemical formula
binary ionic compound
two dif elements (metal and nm)
lose v gain e
metals lose e, nms gain e. number e lost must equal number e gained. the chemical formula reps lowest whole number ratio
why do we change nm ending to ide
its the ion version of the nm
transition metal exceptions
ag+1 zn+2 cadmium +2
why do we use roman numerals for trans metals
they have more than one positive charge
how to do criss cross method
find charge of both (rn is trans metal chatge) and cross down (DOUBLE CHRECK TO MAKE SURE ITS RIGHT IDIOT)
how to find roman numeral
reverse criss cross, check the known anion charge then see if you need to multiply
polyatomic ions
a group of ions that have a charge for the entire grouping, most and in ate or ite
can you change the subscript of a polyatomic ion
no, but you can reduce charges outside the brackets
naming binary acids
H+ and nonmetal anion, hydro_ic acid, find and add h to start
naming ternary acids
H+ and polyatomic ion, dont use prefix hydro, find and add h to start, ate something icky, mite be a hippopotamous
how to tell if its an acid
has h at start
simple ion
charged single element (Na, K), charged particle
complex ion
polyatomic ion, charged group of particles (OH, SO42
when do e share
between two dif nonmetals
greek prefixes
1 mono
2 di
3 tri
4 tetra
5 penta
6 hexa
7 hepta
8 octa
9 nona
10 deca
naming molecular compounds
second element ending is ide, mono is only used on second, all othe prefixes used on both
do you reduce when writing molecular compounds
no, its a formula not a ratio
difference between compounds and molecules
compund- 2 or more dif elements
molecules- 2 or more same or dif
what are the seven elements in nature that appear as a pair if not in compound
HOFBrINCl, written as (N2, nitrogen gas)
physical changes
chemical formula doesnt change, melting, freezing, evaporation, condensation, etc
chemical changes
chemical formula changes, temp, color, state, size, light (2 or more pf those or cant logic explain
reactant
starting substance, left side ->
product
ending substance right side->
+
and or reacts with-(two substances)
->
reacts to form, produces
aqueous
dissolved in water, a solution
word equation
proper chem names and descriptive words to comm changes happening ex) hydrogen gas and oxygen gas react to form water
skeleton equation
shows proper chem formulas and + or -> to comm actions ex) H2+O2 -> H2O
balanced equation
satisfies law of conversion
synthesis
two reactants form one product
decomposition
one reactant forms two or more products
what do things above the arrow
triangle means energy used or a substance is a catalyst
single displacement
one element replaces another element in a compound (sum on its own on each side)
double displacement
two ionic compounds reacts to make two new ionic compounds (nothing by itself)
combustion
made of h and c maybe o
precipitate
solid product milky, grainy, cloudy etc
explain compounds and molecules
all compounds are molecules, but not all molecules are compounds