UNIT 5 Flashcards
- swedish scientist who introduced the modern system of chemical symbols
- represented the elements using one or two letters from their Latin names.
Jöns Jakob Berzelius
- shorthand ways to represent elements in chemistry.
- an element cannot be broken down into simpler substances.
chemical symbols
Importance of Chemical Symbols
- provide standardised ways of representing elements, making communicating information about elements and compounds easier.
- offer a concise and simple way to represent elements in chemical equations, eliminating the need to spell each element’s name.
- Derived from the Greek ‘hydro’ and ‘genes’, which means water forming
- Most abundant element in the universe
Hydrogen
- Name comes from the Greek ‘oxy’ and ‘genes’, which means acid forming
- Essential for life
Oxygen
- Derived from the Latin ‘carbo’, meaning charcoal
- Found in all known life forms
Carbon
- Comes from the Greek ‘nitron’ and ‘genes’, meaning nitre forming
- Constitutes about 78% of Earth’s atmosphere
Nitrogen
- Derived from the Latin ‘natrium’
- Soft metal that easily tarnishes when exposed to air
Sodium
- Name derived from the Greek ‘chloros’, which means greenish yellow
- Widely used in disinfectants and cleaning products
Chlorine
often named based on their characteristics, the substances they were extracted from, how they were found, mythological beings, locations or notable individuals.
elements
There are _____ chemical elements listed in the periodic table in a specific order.
Rules on how to name new elements in the periodic table are set up by the __________________.
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International Union of Pure and Applied Chemistry (IUPAC).
- responsible for establishing unambiguous and consistent naming systems (also known as ___________) and terminology.
- It has a system for naming chemical compounds that provides a standard language for scientists worldwide.
nomenclature
IUPAC
____________: substance containing two or more elements that are chemically bonded.
____________: an expression showing the elements in a compound and their relative proportions. It contains a combination of chemical symbols and numbers.
- compound
- chemical formula
___________: composed of a metal and non-metal
RULES:
1. A metal will always come first in a chemical formula, followed by a non-metal.
* sodium chloride (NaCl)
- An ionic compound with two elements will have a name that ends with -ide.
* copper sulfide (CuS) - A compound with three elements, including oxygen, will have a name that ends with - ate
or -ite.
* sodium sulphate (NaSO₄)
ionic compound
NaCl
CuS
NaSO₄
__________: has two or more non-metals.
RULES:
1. The non-metal furthest to the left on the periodic table comes first.
* carbon dioxide (CO₂)
- A covalent compound with two elements will have a name that ends with -ide.
* sulfur dioxide (SO₂) - Use the prefixes (mono-, di-, tri-, tetra-) to indicate the number of that element in the molecule.
* carbon tetrachloride (CCl₄)
covalent compounds
CO₂
SO₂
CCl₄
H2O
NH3
CH4
water
ammonia
methane
- potassium bromide
- lithium iodide
- carbon monoxide
- sulfuric acid
- potassium nitrate
- KBr
- LiI
- CO
- H2SO4
- KN3
Latin Name
- Potassium
- Sodium
- Silver
- Gold
- Iron
- Lead
- Kalium (K)
- Natrium (Na)
- Argentum (Ag)
- Aurum (Au)
- Ferrum (Fe)
- Plumbum (Pb)
- Mercury
- Tungsten
- Tin
- Copper
- Antimony
- Hydrargyrum (Hg)
- Wolfranium (W)
- Stannum (Sn)
- Cuprum (Cu)
- Stibium (Sb)
Contain an element with more than one oxidation state
multivalent compounds
Low oxidation state:
* affix –ous
High oxidation state:
* affix –ic
Old Method
- Low OS – indicate using roman numerals
- High OS – enclosed in parenthesis
New Method
Old Method and New Method
- FeCl2
- FeCl3
- PbO
- PbO2
Old Method
- Ferrous Chloride
- Ferric Chloride
- Plumbous Oxide
- Plumbic Oxide
New Method
- Iron (II) Chloride
- Iron (III) Chloride
- Lead (II) Oxide
- Lead (III) Oxide
Hydrogen + Non metal
hydroacids
HYDROACIDS
Give the name of the compound and name of the acid
- HCl
- HF
- HBr
Name of the Compound
hydrogen + nonmetal + ide
- Hydrogen Chloride
- Hydrogen Fluoride
- Hydrogen Bromide
Name of the Acid
1. Hydrochloric Acid
2. Hydrofluoric Acid
3. Hydrobromic Acid
___________: Compounds with 3 different elements
_______: Hydrogen + Nonmetal + Oxygen (nonmetal)
ternary compounds
oxyacids
OS of Middle Elements
+7
+6; +5
+4; +3
+1
- HClO4
- HClO3
- HClO2
- HClO
Per + root + ic + acid
root + ic + acid
root + ous + acid
hypo + root + ous + acid
- Perchloric acid
- Chloric acid
- Chlorous acid
- hypochlorous acid
- named by using prefixes to indicate the no. of oxygen atoms in the compound
- CO
- CO2
- SO3
- P2O5
OXYGEN CONTAINING COMPOUNDS
- Carbon Monoxide
- Carbon Dioxide
- Sulfur Trioxide
- Phosphorous Pentaoxide
- A combination of symbols of elements constituting a compound
- Represents the number of atoms present in the molecule of a compound
Formula
- Combining the capacity of an element
- No. of e- (electrons) lost/gained/shared by an atom
- Shown only when atoms are combined
Valence/Oxidation No. or State
Charged particles
* Positive ion (Cation)
* Na+, Ca++, Al+3
* Negative ion (Anion)
* Cl-, S-
Ions
- Contain more than 1 element either positive (+) charged or negatively (-) charged
Polyatomic Ions/ Radical
Rules in Formula Writing
- Write the symbols side by side
- Above each symbol, write the valence
- Criss cross the valences
- Omit subscript whenever it equals to one
- When the radical needs a subscript enclose it with a parenthesis nos.
- Reduce subscripts to small whole
- When a radical already contains a parenthesis, enclose it with a bracket
Rules in assigning Oxidation State
- The oxidation state of an uncombined item/gas is equal to zero
- The algebraic sum of the positive (+) and negative (-) oxidation states in the formula of a compound is equal to zero.
- The algebraic sum of the + and - oxidation states in the formula of a polyatomic ion is equal to the charge of the ion
- State in which the rate of the forward chemical reaction equals the rate of the reverse reaction
- At equilibrium, the concentrations of the reactants and products remain constant over time, though the reactions themselves continue to occur.
chemical reaction
- Substance that undergoes change during a chemical reaction
- interact with each other to form products
REACTANT
A substance that is formed as
a result of a chemical reaction
PRODUCT
- Refers to the state in which the rate of forward chemical reaction equals the rate of the reverse reaction
- At _________, the concentrations of the reactants and products remain constant over time, though the reactions themselves continue to occur
chemical equilibrium
- A numerical value that expresses the ratio of the concentrations of products to reactants at equilibrium.
- This value is constant for a given reaction at a specific temperature.
equilibrium constant
- A rule that states that if a dynamic equilibrium is disturbed by changing the conditions (like pressure, temperature, or concentration), the system will adjust to counteract the disturbance and restore equilibrium.
Le Chatelier’s Principle
types of chemical reactions
- synthesis reaction
- decomposition reaction
- single replacement reaction
- double replacement reaction
- TWO reactants combine to give ONE product
- Union or combination of simple substances to form complex substances (compounds)
- Metal + Oxygen —> Metal Oxide
Mg (s) + O2 —> MgO (s) - Metal + Nonmetal —> Salt
Na (s) + Cl2(g) —> NaCl (s)
synthesis reaction
A + B —> AB
MgO
NaCl
- Breakdown of a more complex substance/compound into its simpler form
- A single substance is broken to give TWO or MORE different substances
- Metal Oxide
HgO (s) —> Hg + O2 - Carbonates and Bicarbonates decompose to yield CO2 when heated
NaHCO3 —> Na2CO3(s) + H2O + CO2
decomposition reaction
AB —> A + B
Hg + O2
- An element replaces another in a compound
- One element reacts with a compound to take the place of the element of that compound
NaOH + HCl —> NaCl + H2O
single replacement reaction
AB + CD —> AD + CB
- TWO compounds exchange partners with each other to produce TWO different compounds (2 or more)
- Combination of 2 or more compounds forming 2 or more different compounds
- Metal: A + BC —> AC + B
Zn + H2SO4 —> ZnSO4 + H2 - Non-metal: A + BC —> BA + C
F2 + HI —> HF + I2
Double replacement reaction
Writing a Chemical Equation
- Identify the reactants and products
- Write the chemical formulas
- Check for state symbols if necessary (e.g. s, l, g, aq)
- Balance the equation
——->
<—–>
arrow up
arrow down
triangle
+
- yields, produces (points to products)
- reversible reactions
- gas evolved (written after the substance)
- solid ppt formed (written after the substance)
- heat
- plus/added to (placed between substances)
_________: contains same no. of each kind of atom on each side of the equation.
It obeys the Law of Conservation of Mass.
Thus, the mass of reactants = mass of products or mass before reaction = mass after reaction
balanced equations
type of chemical reaction that involves the transfer of electrons between two substances
GEROA
LEORA
REDOX REACTIONS
- substance loses electrons
- increasing oxidation state of the substance
OXIDATION
- substance gains electrons
- decreasing oxidation state of the substance
REDUCTION
