Missed Chem/Phys

Question 1

What is the equilibrium point of a solution defined as?

Answer 1

The saturation point is when a solution reaches equilibrium.

• The solution is in a state of dynamic equilibrium, favoring dissolution when dilute and ercipitation when concentrated.
• A free energy of 0 is achived when equilibrium is achived

Question 2

What do all equilibrium constants have in common?

Answer 2

All equilibrium constancts are temeperature dependent?

Question 3

Hydrogen bonds are really just a type of ________

Answer 3

Hydrogen bonds are really just a type of Dipole-dipole interaction.

• they gain strength through the extreme electropositiviy of H when it interacts with F, O, and N

Question 4

What is the definition of boiling point?

Answer 4

The Boiling point of a substance is reached when its vapor preassure is equal to the vapor preassure of the gas above it.

Question 5

What is the use of a vaccum flask in boiling a substance?

Answer 5

Creating a partial vacuum reduces the atmospheric preassure allowing the vapor preassure of a substance to reach the surrounding preassure mych faster, and hence boil more quickly.

Question 6

Fluid pressure changes with depth are assumed to be linear. Which statement best explains why this does not hold true for atmospheric pressure changes?

Answer 6

This question asks us to compare fluid (liquids vs. gases)

The densitiy of a liquid remanis constant as deth changes

Gases, however, have mollecules which are more dispersed compared to a liquid. This means you can force a large ammount of gas into a smaller container which effectivly changes its density (p=m/V)

Question 7

Amides are to ________, as _______ are to alcohols

Answer 7

Amides are to Amines, as Esters are to Alcohols

Question 8

Explain the process below using terms oxidation and reduction

Answer 8

The final accpetor is O2 which is the most electronegative and only species that is not oxidized.

Question 9

________ controls ensure a change in the ________ variable when change is expected

Answer 9

Positive controls ensure a change in the Dependent variable when change is expected

Question 10

_________ Controls ensure __________ in the __________ variable when no change is expected

Answer 10

Negative Controls ensure no change in the dependent variable when no change is expected

Question 11

Because _____ acids and bases _________ ionize, the [H+] and pH (or [OH−] and pOH) are easily calculated, since the concentration of protons or hydroxyl groups is equal to the _______ of the solution

Answer 11

Because strong acids and bases completely ionize, the [H+] and pH (or [OH−] and pOH) are easily calculated, since the concentration of protons or hydroxyl groups is equal to the molarity of the solution

Question 12

Log (1) = ?

Answer 12

Log (1) = 0

Question 13

What is the Henderson Hasselbalch equation

Answer 13

pH = pKa + log [B]/[A]

• If [B] = [A], then the pH = pKa

Question 14

What is the relationship between pKa and acid strength?

Answer 14

The smaller the pKa value, the stronger the acid (since as X increases, pX decreases)

Question 15

When is a wave emitting device’s (which uses the doppler effects) accuracy optimized?

Answer 15

When a wave-emitting detection device is used, its accuracy is optimized if the waves emitted by the device travel directly parallel to the waves that are being measured (θ = 0). The deviation caused by non-parallel angles is known as the cosine effect, because the measured velocity will equal the true velocity × cos(θ).

Question 16

What are aromatic copounds?

Answer 16

Aromatic compounds are conjugated cyclic molecules with a planar structure that also satisfy an additional criterion known as Hückel’s rule: having (4n + 2) π-electrons, where n is an integer. The most important and well-known example of an aromatic compound is benzene. However, many other biologically relevant aromatic rings contain non-carbon molecules, for which reason they are known as heterocyclic rings. These include pyridine (present in the vitamin niacin), pyrimidine and purine (present in nucleic acids), imidazole (present in many important drugs), and pyrrole (which is a component of the porphyrins contained in heme). In contrast, antiaromatic molecules are highly unstable compounds with 4n π-electrons.

Question 17

What is the inductive effect and how does it affect pKb

Answer 17

pKb = -log Kb

the higher the Kb, the stronger the base, and since the pKb is the -log, the smaller the pKb, the stronger the base.

Question 18

What is the difference between an Isovolumetric and an Isochoric process

Answer 18

Nothing, fool, its the same shit.

both of them are processes in which the volume remains the same

remeber that if △V=0, then there is no area underneath the PV curve (see the pic)

Question 19

What happens to density as the temperature decreases?

Answer 19

First, the only variable in density (p=m/V) that can be affected by temp. is Volume.

Charle’s law tells us that V/T, meaning volume and temperature are proportional to one another.

So if temp. goes down then, volume will also decrease accordingly and since Vol. is in the denominator for density, density will go up