Module 3 Solution Chemistry

Question 1

have fixed composition such as elements and compounds.

Answer 1

Pure substances

Question 2

have variable composition

Answer 2

mixtures

Question 3

have a single phase and are the same in appearance throughout

Answer 3

Homogeneous mixtures

Question 4

have two or more distinct phases.

Answer 4

heterogenous mixtures

Question 5

are homogeneous mixtures that are consisted of solute and solvent.

Answer 5

solution

Question 6

contains less amount of solvent

Answer 6

concentrated solution

Question 7

contains more solvent.

Answer 7

dilute solutions

Question 8

The solubility of a particular solute in a given solvent is affected by several factors which includes the following:

Answer 8

particle size, temp, nature of the solute & solvent, pressure

Question 9

which is faster to dissolute, smaller or larger particles

Answer 9

Smaller particle size has larger surface area, thus, there is more points of interaction between the solute and solvent molecules. Therefore, smaller particle size favors a faster rate of dissolution.

Question 10

what happens to the solubility of solid solute in liquid when a there is a higher temp

Answer 10

increases solubility

Question 11

solubility of gas in liquid when temp increases

Answer 11

decreases

Question 12

what rule does solubility follow:

Answer 12

Solubility follows the rule “like dissolves like”. Polar solutes dissolve in polar solvent while nonpolar solute dissolves in nonpolar solvent.

Question 13

pressure affecting solubility only affects?

Answer 13

gaseous solute in liquid

Question 14

increase in pressure is ______ proportional to the rate of solubility og gas

Answer 14

directly proprotional

Question 15

% by mass =

Answer 15

m solute/m sol’n * 100

Question 16

% m/v =

Answer 16

grams solute/mL sol’n *100

Question 17

molarity =

Answer 17

n solute / L sol’n

Question 18

molality =

Answer 18

n solute/kg solvent

Question 19

mole fraction (X) =

Answer 19

n solute/n sol’n

Question 20

Xsolute + Xsolvent =

Answer 20

1

Question 21

ppm =

Answer 21

mg/L or mg/kg

Question 22

ppb =

Answer 22

μg/L or μg/kg

Question 23

ppt =

Answer 23

ng/L or ng/kg

Question 24

Some analysis requires extremely small concentration unit such as those that are done for environmental and medical analysis. For such cases, it is more useful to use

Answer 24

parts per million (ppm), parts per billion (ppb) and parts per trillion (ppt)

Question 25

concentration units that are of central importance to solution chemistry

Answer 25

molarity, molality and mole fraction

Question 26

those that are dependent only on the amount of solute and not on its nature.

Answer 26

colligative properties

Question 27

four specific colligative properties

Answer 27

1) freezing point depression, 2) boiling point elevation, 3) vapor pressure lowering and 4) osmotic pressure.

Question 28

ΔTf =

Answer 28

kf m

Question 29

ΔTf = freezing point depression =

Answer 29

Tf solvent - Tfsolution

Question 30

ΔTb =

Answer 30

kb m

Question 31

ΔTb = boiling point elevation =

Answer 31

ΔTb solution - ΔTbsolvent

Question 32

Kf of H2O

Answer 32

1.86 C/m

Question 33

Kb of H2O

Answer 33

0.512 C/m

Question 34

the pressure that is needed to prevent the process of osmosis is called

Answer 34

osmotic pressure (π)

Question 35

π =

Answer 35

MRT

Question 36

R = gas constant =

Answer 36

0.0821 L-atm/mol K

Question 37

temp in K

Answer 37

+ 273

Question 38

when a solute is added the vapor pressure above the solution becomes lower compared to that of the pure solvent and this is phenomenon is called

Answer 38

vapor pressure lowering

Question 39

formula for vapor pressure lowering according to Raoult’s Law is:

Answer 39

ΔP = mole fraction of solute * vapor pressure of the pure solvent

Question 40

ΔP = P1o – P1

Answer 40

vp pure solvent - vp solvent above the sol’n