Brainscape's Knowledge GenomeTM

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


See full index

LSCI 211 > Water and Molecular Interactions > Flashcards

Water and Molecular Interactions Flashcards

1
Q

Organisms are ___-___% water

A

70/90

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

Water is held together by ____ bonds

A

Hydrogen

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

____ biomolecules are highly soluble in water

A

Polar

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

Why do polar molecules dissolve better in water than non polar?

A

Nonpolar biomolecules interfere with the water-water interactions, they decrease the entropy

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

What are some characteristics of water? Why?

A
  • Relatively high melting, boiling, and vapour point
  • High surface tension
    Caused by attractions between individual water molecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

In water molecules the hydrogen have partial ____ charges and the oxygen has a partial _____ charge

A

Positive/negative

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

Why do water molecules have high attraction to each other?

A

Their partial positive and negative charges attract between molecules

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

When water is heated, bonds break and reform _____. Cohesion is ______.

A

Rapidly/high

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

Why doe side have a high melting point?

A

Water molecules are held in place by a crystalline structure

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

What is ΔH?

A

Enthalpy change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is ΔG?

A

Change in free energy

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

What is Δs?

A

Change in entropy

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

Melting and evaporation occur ______ at room temperature, why?

A

spontaneously, tendency to bond is outweighed by the push to randomness

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

During melting or evaporation ______ increases

A

Entropy

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

H bonds for between _____ and _______, this excludes bonds formed between ______ and _______, which are weakly polar

A

hydrogen/electronegative atoms/hydrogen/carbon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What other types of solutes does water readily dissolve (aside from polar solutes)? How?

A
  • Charged solutes, done by stabilizing the ions which weakens the electrostatic interactions between them which limits their tendency to bond
  • compounds with functional groups, done by replacing the solute-solute H bonds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

H bonds are strongest in a ______ line

A

Straight

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

What are amphipathic biomolecules? Include examples

A

Molecules that are stabilized by their hydrophobic effect, they are important structural determinants, they have both hydrophobic and hydrophilic parts
-ex. proteins, pigments, some vitamins, sterols, membrane proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Van der Waals interactions happens when two _____ molecule are brought close to each other, their _____ _____ influence each other, creating random ______ generation in both atoms which makes weak ______.

A

uncharged/electron clouds/dipole/attractions

20
Q

Each atom has a distinct Van der Waals _____

A

radius

21
Q

_______ and _______ bonds depend on solvent _____ an H ______

A

ionic/H/polarity/alignment

22
Q

Solutes can alter _____ _____ of solvents because they change the _____ of the solvent. These include ____ ____, ______ ______, ______ ______, _____ _____, and _____ _____.

A

Physical properties/concentration/melting point/boiling point/freezing point/osmotic pressure/vapour point

23
Q

In a hypertonic solution, water _____ the cell because solute concentration in the cell __ solute concentration outside the cell.
This causes animals cells to _____ and plant cells to _____.

A

leaves/<

shrivel/shrivel

24
Q

In hypotonic solution, water ____ the cell because solute concentration inside __ solute concentration outside.
This causes animal cells to ____ and plant cells to become ______ which is ____.

A

enters/>

lyse/turgid/ideal

25
Q

In isotonic solutions, water _____ and ____ the cell at an ____ rate, solute concentration outside cell __ solute concentration inside cell.
This causes animal cells to be ____ and plant cells to be _____.

A

enters/exits/=

normal/flaccid

26
Q

Water ionizes to ___ and ___, this is described by the ___ constant. Pure water is ____ ionized.

A

H+/OH-/slightly

27
Q

Weak ____ that dissolve in water contribute ___, called ____. Weak ____ consume ___, called ____.

A

acids/H+/ionizing/bases/H+/protonating

28
Q

Water ionization is _____.

A

reversible

29
Q

pH: total ___ ______ from all sources in a solution

A

H+ concentration

30
Q

Even though H2OH+ +OH- is commonly shown as the equation for water ionization, ____ does not naturally exist in H2O and form ____ immediately instead

A

H+/H3O+ (hydronium ions)

31
Q

How can ionization be measured?

A

Electrical conductivity

32
Q

What is the equilibrium constant?

A

Keq: the position of equilibrium for every equation

Keq=[product of products Keq]/[product of reactants Keq]

33
Q

Ions ____ ____ in their individual directions based on _____, since ___ is especially fast is explains why acid/base reactions are so fast

A

proton hop/charge/H+

34
Q

Ionic product of water (Kw) = ?

A

Kw = Keq[H2O] = [H+][OH-] = 110^-14 M^2

35
Q

pH = ?

A 
pH = -log[H+]
pH = 14-pOH
36
Q

pOH = ?

A 
pOH = -log[OH-]
pOH = 14-pH
37
Q

Strong acids and bases ionize ____.

A

Completely

38
Q

Acids are proton ____ and bases are protons _____.

A

Donors/acceptors

39
Q

Conjugate acid-base pairs:

A

Acids that pair with a base to donate and accept electrons, these are reversible reactions

40
Q

The tendency of an acid to lose a proton and form its conjugate base is defined by:

A

Keq = [H+][A-]/[HA] = Ka

41
Q

Ka represents …

A

the acid dissociation constant

42
Q

pKa = ?

A

pKa = -log[Ka] (analogous to pH)

43
Q

How can pKa for weak acids be found on a titration curve?

A

It is equal to the pH value then the reaction is at 50% OH- added, the point where concentration of proton donor = proton acceptor

44
Q

What is the buffering region? Where can it be found on a titration curve?

A

It is the region where the amount of base added makes very little difference to the pH, usually surrounding the pKa point on a titration curve in the area that is mostly horizontal

45
Q

Titration ends when pH=__ and all protons are _____

A

7/converted

LSCI 211 (14 decks)

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