Exam Pratice Flashcards
What are Hydrocarbons ?
Is a compound of Carbon and Hydrogen atoms only
What are alkenes ?
They are hydrocarbons which have double covalent bonds between carbon atoms .
Double bonds involve carbon carbon bonds.
They are unsaturated because they do not have the maximum number of hydrogens attached to it By having at least one double bonds
They bonds can be broken and can have a potential for more hydrogens atoms to join.
What are alkanes
They are also hydrocarbons which contain single carbon carbon bonds .They are saturated which means they contain the maximum number of hydrogen atoms which are attached to it .
Functional Groups
Collections of atoms at a site that have characteristic behaviour in all molecules . For example -OH for Alcohol . Hydroxl group
Molecular Formula
Suggest the relative number of atoms present in one molecule of a given compound .For example for Ethane is C2H4.
Structural Formula
Drawing
Indicates how the number of different atoms are connected to one another .
List the First 10 of Hydrocarbons
- Methane CH4
- Ethane C2 H6
- Propane C3 H8
- Butane C4 H10
- Pentane C5 H12
- Hexane C6H14
- Heptane C7H16
- Octane C8H18
- Nonenae C9H20
- Decane C10 H22
Always count the number of carbons to identify the element.
What is Aliphatic Compounds ?
They are an organic Compound containing carbon and hydrogen which is joined together in straight chains ,branched chains or non -aromatic rings Forming straight chains
What is Aromatic Compounds ?
Have one or more rings that have alternating single or double bonds in their chemical structure .
What are Alkynes?
They are unsaturated hydrocarbons which contain a triple bonds
They have high energy bonds although they have low stability.
examples : Ethyne
Differentiation between organic building blocks ?
Hydrocarbons -Oxygen /Carbon H
Carbohydrates/lipids: Oxygen Group O
Nitrogen: Amino Acids and Proteins N
Sulphur -Amino Acids /Proteins more of them
Phosphate -Nuclei Acids /RNA /DNA
Lewis Structure
Structural Representations of molecules where dots are used .
For example NH3 doesn’t bind you leave it as a lone pair.
Kokulu Structure
Structural Representations of molecules using lines .
What are the common Side chains?
CH3 -Methyl
CH3 H2 - Ethyl
CH3 CH2 CH2 -Propyl
CH3 CH2 CH2 CH2 -Butyl Condensed Formula
When does Hybridisation occur ?(Alkane )
They are formed when the 2s orbital and three 2 p orbitals in Carbons outer shell rearrange themselves into four identical orbitals each containing .
What are Structural Isomers ?
They are molecules with the same molecular formula but different Structural Formula .
Skeletal Drawing with lines for example
Pentane has 5 points
2-Methylpentane
Cycle hexane for example Circle ring
What is the Sturtcure of the ATom ?
Nucleus which is positively charged due protons contains neutrons aswell
Electrons which are negatively charged and orbit the nucleus
What is the atomic number ?
Is the number of protons in the atoms nucleus
What is the mass number
The number of protons and neutrons
What are isotopes ?
They are atoms of the same element that have different numbers of neutrons and therefore different mass numbers .
Example : Carbon 12 /Carbon 14
Carbon 12
6 Protons
6 electrons
6 neutrons
Carbon 14
6 protons
6 electrons
8 Neutrons
To get Neurons minus the mass with the atomic nuber
What is the mass and charge of Protons/Neutrons and Electrons
Mass :
P=1
e=0.0005
n=1
C=
P=1
E=-1
N=0
What do groups show ?
The number of electrons in outer shell.
What do Periods Show ?
They show the number of shells of electron it has ?
What does /Polar non-polar mean ?
If it is polar then one of the element has more electronegativity and hence pulls the shared pair of electrons towards itself while non polar means that all elements have equal say control over the shared pair.
List the electron confriguation of the following nunbers :
Lithium =3 Nirogen =7 Sodium =11 Potassium = 19 Calcium =20
1s2 2s1-Lithium Nitrogen=1s2 2s2 2p3 Sodium = 1s2 2s2 2p6 3s1 Potassium =1s2 2s2 2p6 3s1 Calcium = 1s2 2s2 2p6 3s2 3p6 4s2
Quantum Mechanics ?
Strongly depend on the physical forces acting on the particle usually these are electrostatic influence
Within each shell there are subshells .In which they have a degree of fine sturtcure inw hcih there are more specific locations in which are known as atomic orbitals .Have a unique shapes which can hold two ekectorns
What was Aufau Principle ?
The aufbau principle states that in the ground state of an atom or ion, electrons fill atomic orbitals of the lowest available energy levels before occupying higher levels. For example, the 1s shell is filled before the 2s subshell is occupied. In this way, the electrons of an atom or ion form the most stable electron configuration possible.
What was Bohr view ?
Believed that electrons can only exist in fixed orbits or shells and no were in between .
What is the stable octet rule ?
Atoms follow the octet rule because they always seek the most stable electron configuration.
FULL OUTER SHELL
What is the electronegativity ?
is the tendency to attract bonding pair of electrons
Polar
Distribution is not symmetrical .
In which they have permanent positive and negative end
Opposite charge attract each other .
Include HC1
difference in electronegativity
A polar bond is a covalent bond between two atoms where the electrons forming the bond are unequally distributed. This causes the molecule to have a slight electrical dipole moment where one end is slightly positive and the other is slightly negative.
The charge of the electric dipoles is less than a full unit charge, so they are considered partial charges and denoted by delta plus (δ+) and delta minus (δ-). Because positive and negative charges are separated in the bond, molecules with polar covalent bonds interact with dipoles in other molecules. This produces dipole-dipole intermolecular forces between the molecules.
Examples of pOLAR
Water (H2O) is a polar bonded molecule. The electronegativity value of oxygen is 3.44, while the electronegativity of hydrogen is 2.20. The inequality in electron distribution accounts for the bent shape of the molecule.
The oxygen “side” of the molecule has a net negative charge, while the two hydrogen atoms (on the other “side”) have a net positive charge.
Hydrogen fluoride (HF) is another example of a molecule that has a polar covalent bond. Fluorine is the more electronegative atom, so the electrons in the bond are more closely associated with the fluorine atom than with the hydrogen atom.
A dipole forms with the fluorine side having a net negative charge and the hydrogen side having a net positive charge. Hydrogen fluoride is a linear molecule because there are only two atoms, so no other geometry is possible.
Non-Polar
For example Non polar atoms have similar electronegativity
They are evenly distributed
Examples include
Oxygen .
What is inductive effect ?
Its the shifting of electrons in bond in response to electronegativity of nearby atoms .
Electronegativity between 0.5-1.7 is what ?
Polar
An electronegativity lower than 0.8 is ?
Ionic
An electronegativity greater than 0.5 is ?
Non-polar
Is Fluorine more reactive and why ?
Fluorine is more reactive because it needs to complete
its shell due to having one more and to become stable.
chlorine is less reactive than fluorine because the outer electrons in a chlorine atom are further from the nucleus than the outer electrons in a fluorine atom. It is harder for a chlorine atom to gain an electron than it is for a fluorine atom.
Metals on the left side are what ?
They attract electrons weakly lower electronegativity .
Halogens and other reactive non-meals on right side of periodic table ?
They attract electrons strongly and therefore have higher electronegativity .
What does Anion mean ?
Negative Charged
What does Cation ?
Positive charged
What are formal chagers ?
If the atoms has one more electron in the molecule it its shown with a - charge
I
If the atoms has one less electron its shown with a + charge.
Neutral molecules with both + and - are dipolar
Pauli exclusion Principle
Electron spin can have only two orientations up and down .
Only two electrons can occupy an orbital and they must be opposite spin .
Hands Rule:
If two or more empty orbitals of equal energy are available ,electrons occupy each with spins parallel until all orbitals have one electron.
Metals loose or gain ?
Do metals lose or gain electrons in a chemical reaction? They lose electrons. Metals are electropositive, meaning it loses its outer shell electrons (valence electrons) easily.
Non-metals ?
easily share or gain valence electrons
