Categorie: Tutti - chemistry - forces - bonds - electrons

da ROJAN REZAEETAZANGI manca 1 anno

202

CH4 +2O2 → CO2 + 2H2O

Chemical interactions are fundamentally influenced by the nature of chemical bonds and the resulting molecular structure. These bonds can be characterized by the sharing or transfer of electrons, leading to different types of bonds such as ionic and covalent.

CH4  +2O2 → CO2  + 2H2O

The further it gets from neutral the stronger acid or base is

Difference in electronegativity

more than 1.7

more than zero bigger or equal to 1.7

equals to zero

Non-polar molecule

If there are any lone pairs (it means nonbonding) on the central atom, then the molecule is polar. but there are exceptions: linear and square planer

If all electron density regions are the same which they should be all bonded electrons then the molecule is non-polar because of the symmetry

PH scale

Neutral(7)

Between 7.1-14

Between 0-6.9

First ionization energy

How easy it is for an atom to lose electron. Easier to lose= lower ionization energy

CH4 +2O2 → CO2 + 2H2O

Chemical reaction

Reaction/No reaction
Chemical equation
Balancing

Law of conservation of mass (Lavoisier)

In chemical reactions, no mass is lost or gained.

Solution
Solvent

The pure substance that will dissolve the solute.

Solute

The pure substance being dissolved

Solubility

The measurement of how well a solute will dissolve in a solvent at a given pressure and temperature

ability of a solute to dissolve

Insoluble

Percipitate

a solid formed in a chemical reaction

Soluble

word equation
Methane reacts with Oxygen gas to produce Carbon dioxide and water.
Types
Displacement

Single

When a free element replaces with a less active element that is in a chemical compound. (based on reactivity charts of metals and non-metals)

Double

Double displacement will not happen unless either water or a precipitate is being formed.

To predict if the double displacement reaction can occur or not we should use solubility rules chart.

Solubility rules

Neutralization

This type of reaction happens when an acid and a base combine to form water and salt.

Synthesis

When two or more reactants combine and form a new product

Combustion

When a fuel (especially hydrocarbons) burns with oxygen to form carbon dioxide and water.

Decomposition

When one reactant breaks to form multiple products

Quantities in chemistry

Yield
How much of a product we expect to get based on calculations

Percent Yield=Actual Yield/Theoretical Yield x 100%

Molar mass
Mass
limiting and excess reactants
In chemistry we use stoichiometry to determine which reactant yields the smaller mass of product in a chemical reaction.
Stoichiometry
The study of quantitative relationships in chemical reactions
Dilution
Final
Initial

Stock solution

Concentration
n

V

C

Avogadro
Avogadro discovered in exactly 12g of carbon there were 6.02 x 10*23 carbon atmos. this number is called ''Mole''

1 Mole=6.02 x 10*23 things

Factor label formula
What you can find=what you know X the fraction(s)you need to get to the answer

We use this formula to switch back and forth between different units and muasurments

Units

L

Kg

Solution and gases

Indicators
indicators are chemicals that when it is dissolved in acid or bases it would change the colour so it would make it easier for us to recognize them.

Most acid and bases are colourless and clear it's hard to distinguish them so it's better to use indicators

Bronsted-Lowry Acid and Bases
When an acid and base are mixed together, the acid will transfer a proton to the base.

HCL + H2O = H3O + CL

Chlorine gas ( The conjugate base)

Hydronium (The conjugate Acid)

Water (The Bronsted Lowry base)

hydrochloric acid (The Bronsted Lowry acid)

Bases
Potassium hydroxide(KOH)
Most of the bases contain a metal and a hydroxide polyatomic group.
Substances that produce hydroxide ions and take a proton from another compound.
Acids
Substances that produce hydrogen ions in solution and donate proton to another compund.
Oxyacids

It contains hydrogen and a polyatomic that has hydrogen.

''ic'' acids

Nitric acid(HN3)

''Ous''acids

Nitrous acid(HNO2)

Binary

contains a hydrogen and another nonmetal

hydrochloric acid (HCl)

Solubility curves
The relationship between solubility and temperature can be expressed by a solubility curve.

Solubility of CH4 in water

Solubility curves shows the maximum amount of solute that can be dissolved in a given amount of water over a range of temperatures.

Reading solubility curves

Super Saturated

Above the line

Saturated

Directly at the line

Unsaturated

Below the line

Titration
Is the process to measure the concentration or volume of a substance by adding a certain amount of another substance

The periodic table

Trends
Electronegativity

Tendency of an atom to attract shared pair of electrons within a molecular bond.

Electronegativity of elements

Affinity

How easy it is for an atom to gain electron. Easier to gain= higher electron affinity

Reactivity of non-Metals

How easily a non-metal would become an anion.

Reactivity of Metals

How easily a metal would become a cation.

Atomic radius

The distance from nucleus to the outermost shell.

Properties
Chemical
Physical
Diagram
Bohr
Orbital
Lewis

compound lewis structure

Chemical element
Metals

Cation

Non-metals

Anion

Isotopes

Average weight

Multivalent
Atomic mass
atoms

Atomic theory

Jemes Chadwick model

Bohr model

Rutherford and Nuclear model

Thomson model

Dalton model

Greek model

Electron

Neutron

Proton

Chemical compound

bond polarity(Intramolecular forces)

This type of force is within the molecules(strong)

The type of bond will be determined by the difference in electronegativity of two atoms.

Ionic

Transfer of electrons

Molecular

sharing electrons

Intermolecular forces(molecule polarity)

This type of forces is between the molecules(weak)

Hydrogen bonding

A special type of dipole-dipole which occurs between hydrogen and either oxygen, nitrogen and fluorine. This intermolecular has a strong attraction because of big difference in electronegativities.

Dipole-Dipole

This intermolecular force forms between a slightly negative end of one Polar molecule and a slightly positive end of a neighbouring molecule causing them to pull towards each other

London dispersion

Electrons are always moving, sometimes they bunch up on one side of an atom, causing them to be slightly negative.

If this happens to a neighbouring molecule at the same time there would be a temporary attraction called London dispersion.

Polarity

Non-polar

Polar

Vsper shape

Vsepr shape allows us to predict the individual molecule structure and it's polarity based on the number of electron pairs that surround the center atom.

Valence shell electron pair repulsion theory