BIOCHEMISTRY REVISION QUESTIONS
AND THEIR ANSWERS
chemical formula for water
H₂O
polar molecule
molecule has positive and negative sides DUE to unequal
sharing of electrons
examples of polar molecules
salt, sugar, water
non-polar molecule
molecule that shares electrons equally and does not have
oppositely charged ends
examples of non-polar molecules
oils, fats, waxes
cohesion
attraction between like molecules (two water molecules)
adhesion
attraction between unlike molecules (water and glass)
meniscus
curved water line at top of graduated cylinder
why does a meniscus form?
DUE to adhesion of water and glass being stronger than
the cohesion of the water droplets
mixture
substances physically mixed together
suspension
molecules are not dissolved into solute (sand and water)
, solution
two or more substances evenly distributed throughout
mixture
solute
substance dissolved into solvent
solvent
substance that the solute dissolves into
in chocolate milk, what is the solute?
chocolate
in chocolate milk, what is the solvent?
milk
pH value
measures the concentration of hydrogen ions in solution;
pH scale range
scale is 0-14
acid
substance that forms hydrogen ions (H+) when dissolved
in water;
range of acids
pH values of 0-6
strongest acid value
0
example of strongest acid
battery acid
weakest acid value
6
base (alkaline)
substance that forms hydroxide ions (OH-) when dissolved
in water;
range of bases
pH values of 8-14
AND THEIR ANSWERS
chemical formula for water
H₂O
polar molecule
molecule has positive and negative sides DUE to unequal
sharing of electrons
examples of polar molecules
salt, sugar, water
non-polar molecule
molecule that shares electrons equally and does not have
oppositely charged ends
examples of non-polar molecules
oils, fats, waxes
cohesion
attraction between like molecules (two water molecules)
adhesion
attraction between unlike molecules (water and glass)
meniscus
curved water line at top of graduated cylinder
why does a meniscus form?
DUE to adhesion of water and glass being stronger than
the cohesion of the water droplets
mixture
substances physically mixed together
suspension
molecules are not dissolved into solute (sand and water)
, solution
two or more substances evenly distributed throughout
mixture
solute
substance dissolved into solvent
solvent
substance that the solute dissolves into
in chocolate milk, what is the solute?
chocolate
in chocolate milk, what is the solvent?
milk
pH value
measures the concentration of hydrogen ions in solution;
pH scale range
scale is 0-14
acid
substance that forms hydrogen ions (H+) when dissolved
in water;
range of acids
pH values of 0-6
strongest acid value
0
example of strongest acid
battery acid
weakest acid value
6
base (alkaline)
substance that forms hydroxide ions (OH-) when dissolved
in water;
range of bases
pH values of 8-14
