Exam 4

Question 1

Solute

Answer 1

the thing being dissolved

Question 2

Solvent

Answer 2

the thing doing the dissolving

Question 3

Solution

Answer 3

A homogeneous mixture of two or more substances

Question 4

colloid

Answer 4

a very finely divided substance which is scattered throughout another substance

Question 5

What substances are soluble together?

Answer 5

“like dissolves like”; nonpolar and nonpolar; polar and polar; polar and ionic

Question 6

What is a saturated solution?

Answer 6

Solutions that contain the maximum amount of solute at a specific temperature

Question 7

What are unsaturated solutions?

Answer 7

Solutions that contain less than the maximum amount of solute at a specific temperature

Question 8

What is a super-saturated solution?

Answer 8

Solutions that contain more than the maximum amount of solute with a change in temperature

Question 9

How are supersaturated solutions made?

Answer 9

By forming a saturated solution at a high temp then cooling the solution without disturbing. (Disturbing the solution with cause the solute to crystalize out of the solution.)

Question 10

How is solubility measured?

Answer 10

As the amount of solute that can dissolve in a specific amount of solvent at a given temperature and can be affected by temperature

Question 11

What happens to a solids solubility as temperature increases?

Answer 11

The solid will become more soluble

Question 12

What happens to a gases solubility as temperature increases?

Answer 12

The gas will become less soluble

Question 13

What is Dilution?

Answer 13

Adding solvent (usually water) to a concentrated solution to decrease the concentration. volume goes up and concentration goes down

Question 14

What happens to dissolved ionic compounds?

Answer 14

They dissociate into ions (electrolytes) when dissolved in water, which creates electrical conductivity

Question 15

What are strong electrolytes?

Answer 15

Only exist as ions in solution (ionic compounds)

Question 16

What are weak electrolytes?

Answer 16

Exist as ions & molecules in solution (semi-ionic with non-metal cation)

Question 17

What are non-electrolytes?

Answer 17

Exist only as molecules in solution (polar covalent molecules)

Question 18

What is OSMOSIS?

Answer 18

When a semi-permeable membrane separates sides of different concentration, water will flow through the membrane from the side of lower solute concentration to higher solute concentration to try and dilute it.

Question 19

What does the movement of water create?

Answer 19

Hydrostatic pressure

Question 20

What is osmotic pressure?

Answer 20

The pressure required to prevent the net flow of water through a semi-permeable membrane

Question 21

What is an isotonic solution?

Answer 21

Equal osmolarity of solute inside and outside cell (happy cell)

Question 22

What is a hypotonic solution?

Answer 22

When concentration inside the cell is greater than outside the cell (cell burst = hemolysis)

Question 23

What is a hypertonic solution?

Answer 23

When concentration outside the cell is greater than inside the cell (cell shrivel up = crenation)

Question 24

What is dialysis?

Answer 24

Movement of solute from higher to lower concentration through dialysis membrane

Question 25

How to dialysis and osmosis differ?

Answer 25

In osmosis ONLY the SOLVENT can cross the membrane. In dialysis, small solute particles can move into the lower solute concentration to equalize concentrations. (In addition to regular osmosis movement)

Question 26

What is an Arrhenius acid? How do you identify such acid?

Answer 26

Produces H+ ions when dissolved in water: To identify look for hydrogen atom at the beginning of its chemical formula, typically bonded to a highly electronegative element like oxygen or a halogen

Question 27

What is an Arrhenius base? How do you identify such base?

Answer 27

Produces OH- ions in water: To identify look for a compound that, when dissolved in water, produces hydroxide ions (OH-) as its primary dissociated ion

Question 28

What is a Bronstad-Lowry acid? How do you identify such acid?

Answer 28

H+ ion donor: To identify observe the reaction and count the hydrogens on each substance before and after reaction

Question 29

What is a Bronstad-Lowry base? How do you identify such base?

Answer 29

H+ ion acceptor: To identify, if the number of hydrogens has increase that substance is the base

Question 30

What are the six strong acids?

Answer 30

HClO4, HNO3, H2SO4, HCl, HBr, HI

Question 31

Why do conjugate/base pairs exist?

Answer 31

This is because when an acid reacts with a base, the acid donate a proton to the base, which accepts it. Whatever the acid changes into, in the reverse reaction, acts as a base, by accepting a proton to reform the original acid.

Question 32

How can acids be classified?

Answer 32

Acids can be classified as monoprotic, diprotic, or triprotic based on H+ available to donate

Question 33

What is water?

Answer 33

Water AMPHOTERIC. This means it can wither be an aicd or a base

Question 34

What does it mean for a substance to be amphoteric?

Answer 34

The substand must have H to give away (act as a acid) and either negative charge or lone pair of electrons where it can accept H (act as a base)

Question 35

What is a strong acid?

Answer 35

Dissociates completely (or nearly so), meaning once they reach equilibrium there are almost no undissociated acid molecules remaining, the mixture will have mostly ions

Question 36

What is a weak acid?

Answer 36

Only dissociate a small amount, meaning once they reach equilibrium there will be a lot of undissociated acid molecules & very little ions.

Question 37

How do weak acids and strong acids differ when dissolved in water?

Answer 37

A strong acid completely dissociates into its ions, releasing all its hydrogen ions and creating a high concentration of H+ ions in the solution. While, a weak acid only partially dissociates, resulting in a much lower concentration of H+ ions due to equilibrium between the undissociated acid molecules and it ions.

Question 38

What are buffers?

Answer 38

Solution that resist change in pH when small amounts of acid/base are added (*contain weak acid and conjugate base*)

Question 39

What happens in a buffer solution when acid is added?

Answer 39

Added acid reacts with conjugate base to make more weak acid; this cause pH to decrease slightly

Question 40

What happens to buffer solution when base is added?

Answer 40

Added base reacts with weak acid to make more conjugate base; this causes the pH to increase slightly

Question 41

When do buffers function optimally?

Answer 41

At a pH level near the pKa value

Question 42

When buffer contains equal amounts of the weak acid and congate base. What is the relationship between pH and pKa values?

Answer 42

pH = pKa

Question 43

If weak acid > conjugate base

Answer 43

pH is slightly below pKa

Question 44

If conjugate base < weak acid

Answer 44

pH is slightly above pKa

Question 45

What is the main buffer system of the body?

Answer 45

H2CO3+H2O ----> HCO3- + H30+ its controlled by CO2

Question 46

What is a neutralization reaction?

Answer 46

Acid + Base (hydroxide) = water and a salt HCl + NaOH ----> H-OH + NaCl

Question 47

What is a special neutralization reaction?

Answer 47

Acid + carbonate/bicarbonate = release CO2 gas (and water + salt)

Question 48

Conjugate acid/base reaction with acid and AMINE (N- containing organic molecule)

Answer 48

Acid + Ammonia (or derivative) ----> ammonium salt ex. NH3 + HCl ----> NH4Cl (NH4 = 1+ and Cl = 1-)

Question 49

Concentration of an unknown acid or base can be found from ________

Answer 49

titration