Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Environmental Chemistry > Lecture 3 > Flashcards

Lecture 3 Flashcards

You may prefer our related Brainscape-certified flashcards:
Periodic Table flashcards Chemistry 101 flashcards AP® Chemistry flashcards Organic Chemistry 101 flashcards
1
Q

How does molecular properties, chemical properties and observable effects, effect each other?

A

Molecular prop. determine —> Chemical prop. which determine —> observable effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Name 9 molecular properties.

A
  1. Size (big: lower volability, not easily vaporized —> less toxic)
  2. Form
  3. Electron distribution (e-clouds)
  4. Electron mobility (how easy the e- in the molecule can move around)
  5. Dipole moment (tells you how polar the molecule/bond is. C-Cl: Cl higher e-neg. —> pulls e-)
  6. Polarisability (defines how easy the e-clouds of a molecule can be pulled away by an external electric field.
    - C-SH and C-CL: not strong e-neg, doesn’t bind e- very strongly—> high polarisability
    - C-O and C-F: binds the e- stronger —> low polarisabillity))
  7. Charge (+/-)
  8. Electrophilicity (likes e-, will accept e-)
  9. Nucleophilicity (likes nucleus, e-rich, donates e-)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Name 9 chemical properties.

A
  1. Volatility (how easily a substance can vaporize)
  2. Solubility (tells lipophilicity and hydrophilicity)
  3. Reactivity (how molecules reacts in different environments)
  4. Lipophilicity (very lipophilic molecules can go to our brain because our brain is fatty)
  5. Hydrophilicity (water loving)
  6. Surface activity (the property possessed by some solid substances that can influence the surface tension of liquids, like making oil and water mix)
  7. Excitability (absorb light)
  8. Acidity/basicity (if the chemical is an acid or base)
  9. Absorption/adsorption (abs: a sponge —> goes inside, ads: get something on the surface)
    - abs: molecules goes inside and over to the next phase
    - ads: molecules stick to the surface of the other phase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Name 8 observable effects.

A
  1. Irritating
  2. Carcinogenic (cancer)
  3. Accumulating (if a stable chemical doesn’t want to metabolize, and it’s very hydrophobic+lipophilic —> will be stored in our bodies/brains —> will not go anywhere —> will accumulate)
  4. Persistent (resist changes in nature, like benzene with a lot of Cl/F are usually very resitant/persistent in nature, will stay in the environment without changes)
  5. Allergenic (some molecules can cause allergies)
  6. Intoxicating (make you feel dizzy, drunk)
  7. Burning
  8. Explosive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which one is dangerous to humans: electrophiles or nucleophiles?

A

Electrophiles are always dangerous!

Nucleophiles aren’t dangerous.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Can we have both electrophiles and nucleophiles in our body? Why/why not?

A

No we can’t. If we had both they would react and we don’t want reactions. Nature constructed our bodies with nucleophiles so we are weak nucleophiles. H20, proteins (amino groups, OH, SH), DNA are all nucleophiles —> we usually do not want electrophiles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What three chemical properties will effect the toxicological aspect?

A

Volatility, solubility and reactivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What determines a molecules volatility?

A

Size (large: low volatility) and intermolecular forces (strong intra. mole. forces: high boiling point, lower volatility)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the best way to measure a morlcules volatility?

A

The boiling point. High boiling point —> low volatility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Name 4 intermolecular forces. Also mention if they are strong or not.

A
  1. Ionic forces (strong)
  2. Hydrogen bonds (strong)
  3. Dipole interactions - with polar groups (not that strong, but much stronger than van der Waals)
  4. van der Waals forces (if a molecules doesnt have any polar groups, like benzene, hexane, they will only have van der Waals forces)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does the molecules shape matter?

A

More branches: lower boiling point (because the surface area differs)
They could have the same molecular weight and look almost the same except for one atom but the boiling points could differ a lot. This could depend on that one molecule has a higher dipole moment —> higher boiling point)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does solubility tell us about a chemical?

A

It determines how a chemical us taken up by an organism and distributed in it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

In what kind of “material” are lipophilic, or hydrophobic, compounds soluble in?

A

They are soluble in fat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

In what kind of “material” are hydrophilic, or lipophobic, compounds soluble in?

A

They are soluble in water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

A pratical measure for solubility is P (or logP). What does it stand for?

A

LogP is a scale of solubility between two solvents: water and octanol. A negative logP value indicates preferential solubility in water and a positive logP value indicates an affinity for octanol.

  • lower: hydrophilic
  • higher: more hydrophobic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Say if the following are hydrophobic or hydrophilic:
OH?
C?
COOH?

If a molecule has 5 OH and 6 C, is it hydrophobic or hydrophilic?

A

OH: hydrophilic
C: hydrophobic
COOH: hydrophilic
The molecule is highly hydrophilic, logP=-3.3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What logP-value does a molecule need to have to be used as a medication?

A

A logP-value between 1-5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What 7 properties decide a molecule’s reactivity?

A
  1. Free radicals
  2. Acids and bases
  3. Oxidative and reductive agents
  4. Explosives
  5. Photo excitable agents
  6. Ligands (non-covalent binding)
  7. Electrophiles (covalent binding)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are free radicals and how do they react with other molecules?

A

Radicals has a single unpaired e-. Radicals normally abstract hydrogen atoms or add to unsaturations.

20
Q

Is a free radical more or less reactive if it has resonance?

A

It’s less reactive. The molecule is stabilized through resonance.

21
Q

In a radical reaction, what is often the product?

A

A new radical is often produced.

22
Q

Is the molecule a acid or a base if it can donate a proton? And if it can accept a proton?

A

Donate proton: acid

Accept proton: base

23
Q

What is an oxidative agent? Name a few oxidizing agents.

A

It’s a substance that has the ability to oxidize other substances - in other words, to accept their electrons. Common oxidizing agents are oxygen, hydrogen peroxide and the halogens.

24
Q

What is a reductive agent? Name a few reductive agents.

A

It’s a substance that has the ability to reduce other substances - in other words, it can donate its electrons. Common reductive agents are earth metals, formic acid (myrsyra), oxalic acid (oxalsyra) and sulfite compounds.

25
Q

What is oxidation?

What is reduction?

A

Oxidation: is the loss of electrons
Reduction: is the gain of electrons

26
Q

What is ROS?

A

Reactive oxygen species. They are often free radicals or are easily transformed into radical compounds.

27
Q

What is photo exitabke agents?

A

????

28
Q

How does small hydrophobic solvents, like ethanol, effect us? What happen in our body?

A

Small hydrophobic solvents can be trapped inside the lipid bilayer of the cell membeane which disturb the function of the nervcells. This is what makes us feek drunk.

29
Q

What does GABA do to our bodies?

A

GABA is the major inhibitory neurotransmitter for the CNS. It inhibits nerve transmissions in the brain, calming nervous activity.

30
Q

Name the 4 types of electrophiles in this course.

A
  1. Leaving group (a good leaving group that the nucleophile can replace)
  2. Strained ring (with a polarised bond that the nucleophile can attack)
  3. Michael acceptors (a polarised unsaturation conjugated with an electron-withdrawing group)
  4. Polarised unsaturation with a leaving group (on the positively charged atom)
31
Q

Electrophiles: What is a leaving group? What is the most important “leaving group reaction”?

A

A leaving group can be replaced by a nucleophile in a reaction called nucleophilic substitution. The most important reaction is the Sn2-type (Sn1 is less dangerous).

32
Q

Why is Sn1 less dangerous than Sn2?

A

Because in Sn1, the electrophile need to kick out the leaving group first, which mean a positive charged ion is left. The carbocation can then react with even very weak nucleophiles (like water).
With Sn2, electrophiles has a higher opportunity to go to the target organ to react with the protein and DNA. This is because water is a weak nucleophile —> may not react with the molecule.

33
Q

What is the general rule for leaving groups?

A

The weaker the base is (corresponding to a strong acid), it makes for a better leaving group.

34
Q

Good or bad leaving groups?

  1. Iodide ion (I-), pKa for HI=10
  2. Methyl sulfate (…-), pKa for sulfuric acid=-9
  3. Sulfate ion (…-), pKa for hydrogen sulfate=2
  4. Acetate ion (…-), pKa for acetic acid=5
A
  1. Strong acid, weak base —> good leaving group
  2. Good leaving group
  3. Ok leaving group
  4. Weak acid, strong base —> bad leaving group
35
Q

What 4 things does Sn2 reactions depend on?

A
  1. The leaving group
  2. The steric hindrance of electrophile
  3. The nucleophile
  4. The condition for the reaction (pH, temperature etc)
36
Q 
Which ones are strong resp. weak nucleophiles:
-SH
-NH2
-O-
-OH
H2O
CH3OH
A

Strong nucleophiles:

  • SH
  • NH2
  • O-

Weak nucleophiles:
-OH
H2O
CH3OH

37
Q

Is a molecule with homogenous bond a better or worse electrophile than a molecule with some polarisation?

A

Worse. The polarisation help to pull e- which makes it easier for the nucleophile to attack —> better electrophile.

38
Q

Which has the higher strains: three rings or four rings?

A

Three rings.

39
Q

What is a Michael acceptor? Name 2 examples.

A

A Michael acceptor is the electrophile of a Michael reaction. Michael acceptors are the substituent groups on the activated unsaturated compound. 2 examples are ketone groups and nitro groups.

40
Q

Michael acceptors: Which one gives a more stable product: an attack on alpha or beta carbon?

A

Beta carbon.

41
Q

Electrophiles - addition/elimination: How does this work?

A

A polarised unsaturation with keaving group on the positively charged atom.

42
Q

Electrophiles - addition/elimination: Which is the most important example?

A

Carboxylic acid halides.

43
Q

Electrophiles - addition/elimination: Why is CH2Cl2 dangerous?

A

Because it can be taken to the liver and be metabolized to acid chloride. Acid chloride itself is not very dangerous but it is very reactive.

44
Q

What does a molecule’s reactivity depend on?

A
  1. Electronic factors (inductive, resonance)
  2. Steric factors
  3. Chemical environment
  4. Metabolism
45
Q

Which is more toxic: heptane or hexane?

A

Hexane.

Environmental Chemistry (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions