LQB182 MidSem Exam| PREDICTED QUESTIONS| WITH COMPLETE SOLUTIONS
Valance shell Correct Answer: Outermost electron shell and its electrons determine chemical
behaviour and bonding
Radioactive isotopes Correct Answer: Useful in medical diagnostic tests and in research
Atoms can gain or lose electrons Correct Answer:
Metals lose electrons and non-metals accept Correct Answer:
Anions Correct Answer: negatively charged ions (gain electrons)
Cations Correct Answer: positively charged ions (lose electrons)
Intramolecular bonds Correct Answer: Strong bonds - ionic, covalent, or metallic bonds
Intermolecular bonds Correct Answer: Weak bonds - hydrogen, dipole-dipole, or London
dispersion forces (Van der Waals)
Ionic bonds Correct Answer: electrons are not shared equally. Strong
Covalent bonds Correct Answer: electrons shared equally. Strong
Metallic bonds Correct Answer: metal ions share electrons. Strong
Hydrogen bonds Correct Answer: occurs when a hydrogen atom in one molecule is attracted to
the electrostatic atom in another molecule. Weak
Dipole-dipole Correct Answer: attractions between oppositely charged regions of polar
molecules. Weak
van der Waals forces Correct Answer: fluctuating polarisation of nearby particles that result in a
bond between oppositely charged regions. Weak
Water interacts with: Correct Answer: Other polar molecules, ionic compounds, things with a
charge
Concentration Correct Answer: n = m/M
Water can self ionise Correct Answer: ionises into hydronium ions and hydroxide ions H3O+
(acidic) and OH- (basic)
Energy-in Correct Answer: build things, join elements together (required for covalent bonds)
, Energy-out Correct Answer: when elements break apart (energy released into surrounding
environment)
Organic molecules with high molecular mass: Correct Answer: comprised of multiple molecules
of smaller mass
Polymers link with monomer units linked via: Correct Answer: covalent bonds
Cellular molecules - 4 major classes Correct Answer: proteins, carbohydrates, lipids, DNA/RNA
Polymerisation Correct Answer: a chemical reaction joining monomers in long chains to form a
polymer
Molecule: carbohydrate -> Monomer: Correct Answer: monosaccharide -> Polymer:
polysaccharide
Molecule: protein -> Monomer: Correct Answer: amino acid -> Polymer: polypeptide
Molecule: DNA -> Monomer: Correct Answer: nucleotide -> Polymer: nucleic acid
Lipids are organic molecules BUT: Correct Answer: not true polymers or true macromolecules
Almost all organic compounds contain: Correct Answer: carbon covalently bonded to hydrogen
(C-H)(exception: carbon tetrachloride, urea)
Inorganic compounds don't have: Correct Answer: C-H. i.e. salt, metal, pure elements
Basic proteins contain: Correct Answer: carbon, hydrogen, oxygen, nitrogen and (some) sulphur
Proteins are a chain of: Correct Answer: amino acids joined together linear making a
polypeptide. proteins can consist of one or more polypeptides.
Amino acid structure Correct Answer: H, NH2, COOH bonded to a central carbon and then a
variable R group
R group (side chain) Correct Answer: a functional group that defines folding characteristics,
charge, hydrophobicity
Hydrophobic Correct Answer: water insoluble. non polar
Hydrophobic, how? Correct Answer: Alkyle groups (CH3) give hydrophobic property. >CH3
>hydrophobic
Hydrophilic Correct Answer: water soluble. polar
Hydrophilic R groups Correct Answer: can form hydrogen bonds (O) in alcohols and amides
Valance shell Correct Answer: Outermost electron shell and its electrons determine chemical
behaviour and bonding
Radioactive isotopes Correct Answer: Useful in medical diagnostic tests and in research
Atoms can gain or lose electrons Correct Answer:
Metals lose electrons and non-metals accept Correct Answer:
Anions Correct Answer: negatively charged ions (gain electrons)
Cations Correct Answer: positively charged ions (lose electrons)
Intramolecular bonds Correct Answer: Strong bonds - ionic, covalent, or metallic bonds
Intermolecular bonds Correct Answer: Weak bonds - hydrogen, dipole-dipole, or London
dispersion forces (Van der Waals)
Ionic bonds Correct Answer: electrons are not shared equally. Strong
Covalent bonds Correct Answer: electrons shared equally. Strong
Metallic bonds Correct Answer: metal ions share electrons. Strong
Hydrogen bonds Correct Answer: occurs when a hydrogen atom in one molecule is attracted to
the electrostatic atom in another molecule. Weak
Dipole-dipole Correct Answer: attractions between oppositely charged regions of polar
molecules. Weak
van der Waals forces Correct Answer: fluctuating polarisation of nearby particles that result in a
bond between oppositely charged regions. Weak
Water interacts with: Correct Answer: Other polar molecules, ionic compounds, things with a
charge
Concentration Correct Answer: n = m/M
Water can self ionise Correct Answer: ionises into hydronium ions and hydroxide ions H3O+
(acidic) and OH- (basic)
Energy-in Correct Answer: build things, join elements together (required for covalent bonds)
, Energy-out Correct Answer: when elements break apart (energy released into surrounding
environment)
Organic molecules with high molecular mass: Correct Answer: comprised of multiple molecules
of smaller mass
Polymers link with monomer units linked via: Correct Answer: covalent bonds
Cellular molecules - 4 major classes Correct Answer: proteins, carbohydrates, lipids, DNA/RNA
Polymerisation Correct Answer: a chemical reaction joining monomers in long chains to form a
polymer
Molecule: carbohydrate -> Monomer: Correct Answer: monosaccharide -> Polymer:
polysaccharide
Molecule: protein -> Monomer: Correct Answer: amino acid -> Polymer: polypeptide
Molecule: DNA -> Monomer: Correct Answer: nucleotide -> Polymer: nucleic acid
Lipids are organic molecules BUT: Correct Answer: not true polymers or true macromolecules
Almost all organic compounds contain: Correct Answer: carbon covalently bonded to hydrogen
(C-H)(exception: carbon tetrachloride, urea)
Inorganic compounds don't have: Correct Answer: C-H. i.e. salt, metal, pure elements
Basic proteins contain: Correct Answer: carbon, hydrogen, oxygen, nitrogen and (some) sulphur
Proteins are a chain of: Correct Answer: amino acids joined together linear making a
polypeptide. proteins can consist of one or more polypeptides.
Amino acid structure Correct Answer: H, NH2, COOH bonded to a central carbon and then a
variable R group
R group (side chain) Correct Answer: a functional group that defines folding characteristics,
charge, hydrophobicity
Hydrophobic Correct Answer: water insoluble. non polar
Hydrophobic, how? Correct Answer: Alkyle groups (CH3) give hydrophobic property. >CH3
>hydrophobic
Hydrophilic Correct Answer: water soluble. polar
Hydrophilic R groups Correct Answer: can form hydrogen bonds (O) in alcohols and amides
