2 Organic and Physical Chemistry Merged Question Pa
Mass number - ANSWER Total number of protons and neutrons.
Atomic number - ANSWER Numbers of protons in the nucleus and number of
electrons in shells.
Negative Ions - ANSWER More electrons than protons.
Positive ions - ANSWER More protons than electrons.
Relative isotopic mass - ANSWER mass of an atom of an isotope of an element on
a scale where an atom of carbon12 is 12.
Relative atomic mass - ANSWER average mass of an atom of an element on a
scale where an atom of carbon12 is 12.
Relative molecular mass - ANSWER average mass of a molecule on a scale where
an atom of carbon12 is 12.
First ionisation energy - ANSWER the energy needed too remove 1 electron from
each atom in 1 mole of gaseous atoms to form 1 mole of gaseous 1+ ions.
Second ionisation energy - ANSWER the energy needed to remove 1 electron from
each ion in 1 mole of gaseous 1+ ions to form 1 mole of gaseous 2+ ions.
Number of particles= - ANSWER Number of moles x Avagadros constant (6.02 x
10^23)
Number of moles= - ANSWER Mass / Mr
Number of moles= - ANSWER Concentration (moldm^-3) x Volume (dm^3)
Methyl orange indicator - ANSWER yellow in acid, red in alkali. Commonly used in
titrations.
Phenolphthalein indicator - ANSWER pink in alkali, colourless in acid. Commonly
used in titrations.
Avogadros constant - ANSWER the number of atoms in 12g of carbon12 (6.02 x
10^23)
Ideal gas equation - ANSWER Pv= nRT
Empirical formula - ANSWER simplest whole number ratio of atoms of each
element in a compound.
, Molecular formula - ANSWER gives the actual numbers of each element in a
molecule.
Percentage yield - ANSWER how much product was actually made compared with
the amount of product that was expected
theoretical yield - ANSWER the maximum mass of product expected in a reaction.
actual yield - ANSWER the mass of product that is actually obtained in a reaction.
Atom economy - ANSWER measure of the efficiency of a chemical reaction. The
proportional mass of reactants that actually become part of the desired product in a
balanced chemical equation.
Ionic bonding - ANSWER Ions (metal and non metal) are held together by
electrostatic forces of attraction due to the transferring of electrons. Eg: Sodium
chloride.
Mass spectrometer - ANSWER An instrument used to accurately determine the
relative atomic mass. Separates atoms or molecules (gaseous positive ions)
according to their charge and mass.
Orbital - ANSWER Region in space where one is likely to find up to two electrons
with opposite spin.
Covalent Bonding - ANSWER holds molecules together by sharing electrons
between non-metals. Eg: I2, Graphite, Diamond.
Dative Covalent Bonding - ANSWER Where both electrons are provided by one
atom for a covalent bond.
Linear molecule - ANSWER 2 bonds 180 degree angles 2D e.g: CO2
Trigonal planar molecule - ANSWER 3 bonds 120 degree angles 2D e.g: BF3
Tetrahedral molecule - ANSWER 4 bonds 109.5 degree angles 3D e.g: CH4
Trigonal bipyramid molecule - ANSWER 5 bonds 120 degree and 90 degree angles
3D e.g.: PCl5
Octahedral molecule - ANSWER 6 bonds 90 degree angles 3D e.g.: SF6
Lone pairs - ANSWER Cause a repulsion of 2.5 degrees.
Charge Clouds - ANSWER What bonding pairs and lone pairs exist as in a
molecule.
Largest repulsion angle in a molecule - ANSWER lone pair - lone pair