Properties of Solutions

Question 1

What about water is the main contributor to its unique properties?

Answer 1

H- bonds (b/w water and also found within the water mlc)

Question 2

What is the polarity of water? What characteristics (3) of water are due to this polarity?

Answer 2

HIGHLY polar (with partially negative O and partially positive H’s; dipole points towards more EN Oxygens) –> allows for H bonds to form with other mlcs (aka cmpds)

HIGH POLARITY leads to these water characteristics:
* cohesion to other water mlcs as well as adhesion to dissimilar mlcs;
* HIGH POLARITY also CONTRIBUTES TO water being the universal solvent aka able to dissolve polar items like ionic cmpds

Question 3

Specific heat and heat of vaporization are low or high for water? What does that mean?

Answer 3

• high
• means that it takes alot of energy to break down H bonds b/w the water mlcs

Question 4

What type of water is LESS dense than what type of water?

Answer 4

• solid water (ie. ice) is LESS dense than liquid water (that’s why ice floats on water)
• this property is the opposite of other substances

Question 5

Water is what type of solvent?

Answer 5

universal solvent
* substances normally dissolve in water to form an aqueous sln (like dissolve like so water readily dissolves polar substances)

Question 6

What makes up a solution?

Answer 6

solute + solvent (putting a solute into a solvent)

Question 7

Describe solutes, solvents, and solutions

Answer 7

• solute: hydrophobic (fat soluble, water insoluble) or hydrophillic (water soluble)-vitamins are water soluble and ADEK are FAT SOLUBLE
• solvent: S, L, or G phases (these phases determine the OVERALL phase of the sln)
• sln: homogenous mixture of substances that DO NOT separate through filtration or centrifugation- saturated: max solutes, unsaturated: less than max solutes; supersaturated: more than max solutes dissolved due to inc in temp

Question 8

• Definition of solubility
• solubility of solid in liquid
• solubility of gas

Answer 8

• the ability of a substance to dissolve in another substance
• solubility of solid in liquid increases with increasing temp
• solubility of gases decreases with increasing temp

Question 9

Define concentration

Answer 9

the quantity of a solute in a given quantity of solution (proportion of solute to solvent in a given solution)

Question 10

In general, what are the units for concentration?

Answer 10

• mole fraction
• molarity
• molality
• mass percent
• ppt (parts per thousand)
• ppm (parts per million)
• ppb (parts per billion)

Question 11

What is mole fraction

Answer 11

moles of solute/ total moles present in the sln

Question 12

What is molarity

Answer 12

moles of solute/ Liters of sln [ dimensional analysis with molar masses as well]

Question 13

What is molality?

Answer 13

moles of solute/ kg of solvent

Question 14

What is mass percent?

Answer 14

[mass of solute in g/ mass of sln in g] x 100

Question 15

What is parts per thousand?

Answer 15

g of solute/ kg of sln

Question 16

What is parts per million?

Answer 16

mg of solute/ kg of sln

Question 17

What is parts ber billion

Answer 17

mcg of solute/ kg of sln

Question 18

• What is the definition of dilution?
• What is the generally the normal solvent used to dilute concentrated slns in lab?

Answer 18

• def: using a solvent to decrease the concentration of a solute in sln
• water

Question 19

• What is osmosis?
• Osmosis is a special type of what?
• Osmosis is active or passive transport? What does that mean?

Answer 19

• diffusion of water
• diffusion (simple- just pass through cell membrane with no channels- or facilitated- use aquaporin channels inserted by ADH/ vassopressin to pass through)
• passive , taking water from high to low conc (down conc gradient) or think as low solute to high solute , which DOES NOT require the use of energy (ATP)

Question 20

What is another way to think about osmosis?

Answer 20

diffusion from low solute (high water) to high solute (low water)

Question 21

If a RBC is placed in a hypertonic sln, what happens?

Answer 21

• hypertonic = more solutes than water, so low water
• water flows from cell (high water) to the outside sln (low water)–> so can shrink the cell

Question 22

If a RBC is placed in a hypotonic sln, what happens?

Answer 22

• hypotonic= less solutes than water, so more water
• water flows from outside (high water) to inside the cell (low water) –> can potentially burst the cell

Question 23

What type of slns should be given to patients?

Answer 23

isotonic sln (same conc of solute inside AND outside the cell)

Question 24

If you are in a bathtub, what happens to ur fingers? What does that mean?

Answer 24

they prune = water is flowing into ur skin (down its concentration gradient)

Question 25

• What is passive transport?
• What are (3) examples of it?

Answer 25

• when a substance is taken from high to low conc (DOWN its conc. gradient), so DOES NOT require energy in the form of ATP

Examples
* simple diffusion: small or nonpolar (hydrophobic, water insoluble) substances ie. CO2 and O2; uses NO channels
* facilitated diffusion: large or polar (hydrophilic, water soluble) substances; uses channels ie. water through ADH/ vassopressin induced channels, glucose through insulin induced channels, voltage gated Na and K channels
* osmosis: diffusion of water (simple or facilitated)

Question 26

• What is active transport?
• What are some examples (3)?

Answer 26

• when substance is moved from low to high conc. (AGAINST its concentration gradient), so REQUIRES energy in the form of ATP

Examples
* Na/ K ATPase ( 321 NoKiA) that maintains high Na outside the cell and high K inside the cell
* endocytosis and exocytosis (but they don’t necessarily go against concentration gradient BUT DO require energy)

Question 27

A mlc with polar bonds can be nonpolar as a whole? T or F?

Answer 27

true as long as the dipoles cancel each other out

Question 28

An item that is more cohesive is less what?

Answer 28

adhesive