Unit 2, Chemistry Flashcards
What are the four clues of chemical change?
- Coulor
- Gas is produced
- Heat is produced
4.Liquis is produced
Elements with similar properties are grouped together into families/coloums called groups.
Locate in the periodic table, # of valence electrons, type of compounds usually formed.
Alkali Metals, Alkaline Earth Metals, Halogens, Noble Gases.
Alkali metals are the first column (-hydrogen), 1 valence electron, ionic.
Alkaline earth metals are second column, 2 valence electrons, ionic.
Halogens are the 17th coloumn, 7 valence electrons, covalent/molecular and ionic.
Noble gases are the 18th(final) coloumn, 8 (full) valence electrons, covalent/molecular and ionic.
Where are nonmetals and metals located periodically
metals are on the left side while nonmetals are on the right, divided by the zig zag line.
Cation definiton + examples
a positivly charged ion formed by less electrons. Ex, Calcium: Ca.2+, Silver: Ag.+, Aluminum: Al.3+
Anions definition + examples
a negativly charged ion formed by more electrons. Ex, Chlorine: Cl. –,
Hydroxide: OH. –, Iodide: I. –
How to find protons
The number of protons is equal to the atomic number of the element.
how to find electrons
If it is a neutral atom, the number of electrons is equal to the proton number(AKA # of the element).
If postivly charged, subtract the charge from # of element.
If negatively charged, add the charge to the # of element.
what is H__________?
H O F Br I N Cl
What are the two types of acids? Whats the difference? How to write names?
Binary and Oxyacids
Binary acids contain hydrogen and another element. Named using prefix -HYDRO-stem of the element name-ends in-ic
Oxyacids contain two or more elements. Commonly H#O. Named the same as binary but without hydro. Closly realted to polyatomics, H+polyatiomic then criss-cross.
Whats an ionic compound
created between a metal and a non-metal, the metal GIVES its valence election(s) to the non-metal
Naming ionic compounds
metal name first then the non-metal name after, change the ending of the non-metal name to -ide.
ex, sodium chlorine –> sodium chloride
Formulas for ionic compounds
symbol of metal first, then symbol of non-metal right beside it, criss-cross the charges of the atoms then write them as subscripts
Naming ionic compounds w/ multivalent metals
same thing as normal namings but must indicate which version of metal in the name by roman numeral
Formulas for ionic compounds w/ multivalent metals
same thing as normal (criss-cross method) but aware of the roman numeral in the name
What is a polyatomic ion
A group of atoms with an overall charge
*-ite is always one less oxygen than -ate
Naming ionic compounds w/ polyatomic ions
same thing as normal naming, the polyatomic acts as the non-metal,
but DO NOT CHANGE THE ENDING OF THE POLYATOMIC
Formulas for ionic compounds w/ polyatomic ions
same thing as normal (criss-cross method)
put brackets around the polyatomic when necessary
What are Molecular/Covalent compounds
compounds that contain 2 non-metals
bond with a SHARED valence electron
Naming molecular/covalent bonds
to name look at the subscripts and use prefixes
if the first non-metal is only one do not write mono- only when its the first
(NO CRISS-CROSS)
Formulas for molecular/covalent bonds
look at the name and determine subscripts based on prefixes
All the prefixes
one - mono
two - di
three - tri
four - tetra
five - penta
six - hexa
seven - hepta
eight - octa
nine - nona
ten - deca
Law of Conservation of Mass
the total mass of the reactants always is the same as the mass of the products
only 100% accurate when the reaction occurs in a completely contained environment, ex if gas is lost then the reactants =/= products
Balancing equations
use coefficients to balance atoms on both sides of the equation
Synthesis
two or more elements or compounds combine to form a new product which is a compound
general formula : A + B = AB
(when writing the product write it as the formula that the reactants would have made.
ex, crisscross method when metal +non-metal)
Decomposition
a compound breaks down into two or more products which are simpler elements/compounds
general formula: AB = A + B
(commonly needs heat to break down the reactant)
SIngle displacement
metal or non-metal is replaced by a MORE REACTIVE metal or non-metal (only replaced by the same ‘thing’, metal on metal, non-metal on non-metal) to form a new element + compound
general formula: A + BC = AC + B
(reaction only happens if the element on the outside is more reactive then the element on the inside)
Double displacement
involving two ionic compounds the cations (+) of each compound switch and form two new compounds which can be ionic or covalent
AB + CD = AD + CB
Combustion
involves the burning of a hydrocarbon(*a compound that has hydrogen+carbon, ex, methane/propane)(fuel) in the presence of oxygen, the products are an oxide and energy
two different types of combustion
1) complete combustion, where the hydrogen burns completely because there was enough oxygen
general formula: C^x H^y = CO2 + H2O + energy
2) incomplete combustion, where the hydrogen doesn’t completely burn due to lack of oxygen
genergal formula: C^x H^y + O2 = CO2 + H2O + CO + C + energy
When an acid and a base are combined whats the result
when an acid and a base are combined the result is H2O and some type of ionic compound (usually a salt)
Neutralization reactions
neutralization reactions are special cases of double displacement reactions
acid + base = (HOH) + ionic compound(salt)
H… + …OH = H2O + ionic comp
The H and OH combine to make water and the other elements combine as a ionic compound
what are acids and bases
they are substances that form ions when dissolved in water
properties of acid
Reacts with metals and carbonates
Conducts electricity
Turns blue litmus paper red
Tastes sour
pH < 7 (low pH its acidic)
Neutralizes bases
properties of base
Conducts electricity
Turns red litmus paper blue
Tastes bitter and feels slippery
pH > 7 (strong pH its a base)
Neutralizes acids
when dissolved in water acids form … and bases form…
acids form hydrogen ions (H+)
bases form hydroxide ions (OH-)
binary acids
only contain two elements hydrogen + another element
they are named using the prefix ‘hydro-‘ + ‘element name’ + ends with ‘ic’
ex, HCl is “hydrochloric acid”
oxyacids
contain more than two elements
anything H…O# is an oxyacid, they are directly related to polyatomics
“main” acids are only polyatomics that end with “ate” and the acid is spelt with ‘-ic’ acid, if the polyatomic ends with “-ite” then it is a -1 Oxygen acid and it ends with ‘-ous’
oxyacid names
+1Oxygen acids are “per”…“ic” acid (O4)
main acids are …“-ic” acid (O3)
-1Oxygen are …“-ous” acid (O2)
-2Oxygen are “hypo”…“ous” acid (O)
these oxygens are all the same unless its sulfuric or phosphoric then each oxygen is one more
