Chemistry Answers

Consider the following two compounds:

          CH₃CH₂CH₂CH₂CH₃   and   (CH₃)₂CHCH₂CH₃

 Which statement below is INCORRECT?

a.

(CH₃)₂CHCH₂CH₃ has the higher boiling point 

b.

CH₃CH₂CH₂CH₂CH₃ has the higher boiling point.

c.

Greater surface area leads to more intermolecular attraction which results in a higher boiling point.

d.

As the degree of branching increases, the surface area of the molecule decreases and the potential for intermolecular attraction via London forces decreases.

The reaction of bromine with propane in the presence of high heat or uv light gives primarily 2-bromopropane as the reaction product because:

a.

bromine forms reactive free radicals.

b.

propane easily forms free radicals

c.

bromine reacts with any alkane to produce predominantly a secondary carbon free radical intermediate.

d.

secondary carbon free radicals are more stable than primary carbon free radicals

Which of the following statements are INCORRECT?

a. Free radicals contain an unpaired electron.

b.Carbocations are electrophilic.

c.Carbanions are strongly acidic.

d.Carbocations are acidic.

The donation of electron density through sigma (σ) bonds of a molecule is called the:

a.

steric effect

b.

inductive effect

c.

nucleophilic effect

d.

resonance effect

Consider the following molecule:

Which statement is INCORRECT?

a.

The molecule has (R)- configuration.

b.

With the lowest (fourth) priority facing away from the viewer, a curved arrow drawn from the first (highest) priority group through the second priority group to third priority group points in a counterclockwise direction.

c.

The molecule has (S)- configuration.

d.

The highest priority group is OH and the lowest priority group is H.

The absolute configuration of a chiral carbon is defined as R- or S- according to the Cahn-Ingold-Prelog rules. What is the CORRECT name for the following compound?

a.

(S)-3-methylheptane

b.

(R)-3-methylheptane

c.

(R)-2-ethylhexane

d.

(S)-2-ethylhexane

Ammonia (NH3) combines with oxygen to give nitrogen monoxide and water. What amount (moles) of oxygen is required to use up 2.75 moles of ammonia?

Write the electron configuration, noble gas configuration, and orbital diagram of the following elements.

1. phosphorus
2. chlorine
3. potassium

Identify the element given the set of quantum numbers of the last entering electron: 2, 0, 0, -1/2

Identify the element given the set of quantum numbers of the last entering electron: 2, 1, +1, -1/2