BIO SCI 93 Midterm #1 Exam Questions
with Revised Correct Detailed Answers
with Rationales Guaranteed Pass
What is a hypothesis? - Answers -✔✔ a testable explanation to a question (can never
be proven)
What is a prediction? - Answers -✔✔ a statement about an uncertain event
What is an experiment? - Answers -✔✔ a scientific test (to show if the hypothesis was
accepted or rejected), carried out in controlled conditions
How is a theory different than a hypothesis? - Answers -✔✔ a theory is broader in
scope, general enough to spin a new testable hypothesis, and it is generally supported
by a greater body of evidence
What is the difference between an element and a compound? - Answers -✔✔ an
element cannot be broken down to other substances by chemical reactions & a
compound is made up of two or more DIFFERENT elements
What is the difference between a single bond and a double bond? - Answers -✔✔ a
single bond is a pair of shared valence electrons & a double bond is the sharing of two
pairs of valence electrons
What is electronegativity? - Answers -✔✔ the attraction of a particular atom for the
electrons of a covalent bond (think oxygen and hydrogen). non polar covalent bonds
share the electrons equally because the atoms sharing them, are equal in
electronegativity; unlike polar bonds (H2O)
What is a salt? - Answers -✔✔ compounds formed by ionic bonds (NaCl)
What are Van der Waals interactions? - Answers -✔✔ weak forces that occur only
when atom and molecules are very close together. they occur because electrons are
not always evenly distributed. (ex: gecko walking on a wall)
Why does it mean when a reaction has reached chemical equilibrium? - Answers -✔✔
It mens is has reached the point at which the reactions offset one another exactly.
What is a molecule? - Answers -✔✔ Two or more atoms covalently bonded together
What is the difference between a non-polar covalent bond and polar covalent bond? -
Answers -✔✔ A non polar covalent bond is a bond where the electrons are being
, shared equally and the restructure of the molecule is equal if you cut it n half (CH4). A
polar covalent bond is a bond that does not share the electrons Evelyn because of the
difference in electronegativity amongst the atoms (H2O)
What is an ionic bond? - Answers -✔✔ A bond between a cation (+) and an anion (-)
where an electron is taken/given
What is hydrogen bond? - Answers -✔✔ A weak bond between two molecules resulting
from the attraction between a proton in one molecule and an electronegative atom in the
other (H2O)
What is a chemical reaction? - Answers -✔✔ The making and breaking of chemical
bonds, leading to changes in the composition of matter. The reactant in a reaction is the
stating material and the product is what you get after the reaction.
What is a solution, solvent, and solute, and an aqueous solution? - Answers -✔✔
Solution: a liquid that is a complete homogenous mixture of two or more substances.
Solvent: a dissolving agent.
Solute: a substance that is dissolved.
Aqueous solution: the solute is dissolved in water; water is the universal solvent
What is the difference between an acid and a base? - Answers -✔✔ Acid: a substance
that increases the hydrogen ion concentration in a solution. Base: a substance that
reduces the hydrogen concentration/increases hydroxide concentration in a solution
(some accept hydrogen ions like NH3 + H+ --> NH4+). Strong acids and bases don't
dissociate completely in water.
What is the pH scale and what is a buffer? - Answers -✔✔ pH scale measure how
acidic or basic a solution is and a buffer is a substance that minimizes changes in [H+]
and [OH-] in a solution. Most buffers contain a weak acid and its corresponding base,
which combines with H+
What are functional groups? - Answers -✔✔ Chemical groups that are directly involved
in chemical reactions. Each functional group has different properties; such as shape
and change, that cause it to participate in a certain way.
Hydroxyl group - Answers -✔✔ Forms hydrogen bonds with water because of its
polarity and it helps dissolve compounds like sugar. An example is ethanol which is an
alcohol (its compound name)
Carbonyl group - Answers -✔✔ Compound name: Ketone. Polar. The sugars with
ketone group= ketoses and sugars with aldehydes= aldoses. A ketone is a carbonyl
group within the carbon skeleton. An aldehyde is the carbonyl group at the end of the
carbon skeleton. An example is acetone (simplest ketone) and propanal (aldehyde).
with Revised Correct Detailed Answers
with Rationales Guaranteed Pass
What is a hypothesis? - Answers -✔✔ a testable explanation to a question (can never
be proven)
What is a prediction? - Answers -✔✔ a statement about an uncertain event
What is an experiment? - Answers -✔✔ a scientific test (to show if the hypothesis was
accepted or rejected), carried out in controlled conditions
How is a theory different than a hypothesis? - Answers -✔✔ a theory is broader in
scope, general enough to spin a new testable hypothesis, and it is generally supported
by a greater body of evidence
What is the difference between an element and a compound? - Answers -✔✔ an
element cannot be broken down to other substances by chemical reactions & a
compound is made up of two or more DIFFERENT elements
What is the difference between a single bond and a double bond? - Answers -✔✔ a
single bond is a pair of shared valence electrons & a double bond is the sharing of two
pairs of valence electrons
What is electronegativity? - Answers -✔✔ the attraction of a particular atom for the
electrons of a covalent bond (think oxygen and hydrogen). non polar covalent bonds
share the electrons equally because the atoms sharing them, are equal in
electronegativity; unlike polar bonds (H2O)
What is a salt? - Answers -✔✔ compounds formed by ionic bonds (NaCl)
What are Van der Waals interactions? - Answers -✔✔ weak forces that occur only
when atom and molecules are very close together. they occur because electrons are
not always evenly distributed. (ex: gecko walking on a wall)
Why does it mean when a reaction has reached chemical equilibrium? - Answers -✔✔
It mens is has reached the point at which the reactions offset one another exactly.
What is a molecule? - Answers -✔✔ Two or more atoms covalently bonded together
What is the difference between a non-polar covalent bond and polar covalent bond? -
Answers -✔✔ A non polar covalent bond is a bond where the electrons are being
, shared equally and the restructure of the molecule is equal if you cut it n half (CH4). A
polar covalent bond is a bond that does not share the electrons Evelyn because of the
difference in electronegativity amongst the atoms (H2O)
What is an ionic bond? - Answers -✔✔ A bond between a cation (+) and an anion (-)
where an electron is taken/given
What is hydrogen bond? - Answers -✔✔ A weak bond between two molecules resulting
from the attraction between a proton in one molecule and an electronegative atom in the
other (H2O)
What is a chemical reaction? - Answers -✔✔ The making and breaking of chemical
bonds, leading to changes in the composition of matter. The reactant in a reaction is the
stating material and the product is what you get after the reaction.
What is a solution, solvent, and solute, and an aqueous solution? - Answers -✔✔
Solution: a liquid that is a complete homogenous mixture of two or more substances.
Solvent: a dissolving agent.
Solute: a substance that is dissolved.
Aqueous solution: the solute is dissolved in water; water is the universal solvent
What is the difference between an acid and a base? - Answers -✔✔ Acid: a substance
that increases the hydrogen ion concentration in a solution. Base: a substance that
reduces the hydrogen concentration/increases hydroxide concentration in a solution
(some accept hydrogen ions like NH3 + H+ --> NH4+). Strong acids and bases don't
dissociate completely in water.
What is the pH scale and what is a buffer? - Answers -✔✔ pH scale measure how
acidic or basic a solution is and a buffer is a substance that minimizes changes in [H+]
and [OH-] in a solution. Most buffers contain a weak acid and its corresponding base,
which combines with H+
What are functional groups? - Answers -✔✔ Chemical groups that are directly involved
in chemical reactions. Each functional group has different properties; such as shape
and change, that cause it to participate in a certain way.
Hydroxyl group - Answers -✔✔ Forms hydrogen bonds with water because of its
polarity and it helps dissolve compounds like sugar. An example is ethanol which is an
alcohol (its compound name)
Carbonyl group - Answers -✔✔ Compound name: Ketone. Polar. The sugars with
ketone group= ketoses and sugars with aldehydes= aldoses. A ketone is a carbonyl
group within the carbon skeleton. An aldehyde is the carbonyl group at the end of the
carbon skeleton. An example is acetone (simplest ketone) and propanal (aldehyde).
