solutions

Question 1

solution

Answer 1

homogenous mixture (2 or more substances mixed together)
evenly dispersed

Question 2

concentration

Answer 2

the quantity of a solute that is contained in a particular quantity of solvent in a solution

Question 3

molarity

Answer 3

measure of concentration of solute in a solution

Question 4

concentrated

Answer 4

relating to large amount of solute dissolved

Question 5

dilute

Answer 5

very small amount of solute or adding the amount of solvent

Question 6

saturated

Answer 6

contains the maximum amount of solute that can be dissolved

Question 7

unsaturated

Answer 7

less than the maximum amount of solute in a solution
ex. salt

Question 8

supersaturated

Answer 8

more than the maximum amount of solute in a solution

Question 9

steps of solution process for a solid solute dissolving in a liquid solvent and state the enthalpy changes associated with each step of the solution

Answer 9

1. bonds form between solute and solvent

• delta h (PE) decreases, delta h is a negative number
• exothermic - warms surroundings

2. bonds within the solute break

• delta h increases, delta h is positive number
• endothermic - cools surroundings

3. bonds within the solvent break

• delta h increases, delta h positive number
• endothermic - cools surroundings

delta h1 + delta h2 + delta h3 = delta hoverall

• depends on the nature of the solvent and solute which could be positive or negative, could be endo/exothermic, could be cooling or warming change

delta h1 > delta h2 + delta h3

Question 10

define enthlapy change of solution

Answer 10

the amount of heat that is released or absorbed during the dissolving process

Question 11

solubility

Answer 11

maximum concentration of solute in solution under EQUILIBRIUM conditions

Question 12

soluble

Answer 12

the ability of a solid, liquid, or gas chemical substance to dissolve in solvent

Question 13

insoluble

Answer 13

a substance that will not dissolve in a solvent when mixing

Question 14

predicting solubility

Answer 14

“LIKE DISSOLVES LIKE” - substances with similar polarity are generally soluble

• polar dissolves polar
• nonpolar dissolves nonpolar
• substances with similar IM bond strengths are generally soluble
  ex. hydrogen bond matter dissolves hydrogen bond matter
• some ionic bonds soluble in water bc their ionic bond strength similar to that of H2O
• all GASES soluble in other GASES
• melted down metals (liquid in liquid) have the same strength —> soluble

SOLUBILITY FOR WATER SOLUTIONS:

• any column 1 metal ion compound is soluble
• any compound containing NO3-, C2H3O2-, or NH4+ is soluble

polar if:

• asymmetrical
• charged

Question 15

enthlapy of a hydrate and explain why this is one factor in prediction of the solubility of ionic compounds in water

Answer 15

NaCl —> Na+ + Cl-

• the sodium ion is hydrated
• there is a hydration shell around the Na+ insulating it from nearby Cl-
• different ions depends on different layers of hydration shells, depending on how strongly they are attracted to the oppositely charge ion
• the more strongly the attraction, the more H2O required to separate the ions
• the stronger the attraction the more likely the ion is likely to form a hydration shell
• when bond forms PE decreases (enthlapy) of the H2O and Na+ decreases
• enthlapy change = - number as bonds breaking between H2O molecule and ion size
• ions that have a large negative enthlapy hydration are usually parts of soluble solutions

What affects negativity of delta h hydration?

• amount of charge on ion
  — the more charge, the stronger the bond, so increase in delta h hydration
• size of ions
  —the closer the distance, the larger the amount of force - based on atomic radius

Question 16

ion-dipole bond

Answer 16

bond between a solute ion and the oppositely charged end of a polar molecule

Question 17

draw a solubility curve for an ionic compound in water

Answer 17

increasing solubility with increasing temperature

look at camera roll

Question 18

draw a typical solubility curve for a gas solute in water

Answer 18

decreasing solubility with increasing temperature

look at camera roll

Question 19

factors that play a role in determining solubility of a solid in water

Answer 19

temperature

Question 20

explain why the solubility of a gas decreases with increasing temperature

Answer 20

the solution is at a higher temperature meaning that there is a higher kinetic energy which causes the gas molecules to be faster which breaks the IM bonds and allows for the solute and solvent solution to empty out

Question 21

explain why the solubility of a gas increases when the partial pressure above the gas increases

Answer 21

if increase in pressure there is increase in amount of gas particles colliding with liquid’s surface which then some gas molecules dissolve into the liquid phase

Question 22

Henry’s Law

Answer 22

S = KP

s = solubility
p = partial pressure
k = constant

Question 23

electrolyte

Answer 23

solute that forms an electrically conductive solution

Question 24

nonelectrolyte

Answer 24

solute that doesn’t form an electrically conductive solution

Question 25

electrolytic solution

Answer 25

a solutions that contains ions and is electrically conductive

Question 26

why solutions of ionic compounds conduct electricity

Answer 26

contain mobile charges

Question 27

given an acid formula write the ionization reaction equation

Answer 27

example:

HCN (aq) + H2O (l) —> H3O+ (aq) + CN- (aq)

one hydrogen off the not water compound
- drop charge by one

Question 28

colligative property

Answer 28

certain solvent properties which changed, the more solvent is added
changes are related to the relative amounts of solute + solvent

ex.
change in vp
change in bp
change in fp