Unit 5 K Review 15-16
Name________KEY____________________
Matching
_____1. Separates substances on the basis of their different boiling points B
a. magnetism
_____2. Separates substances based on their movement through a special paper D
b. distillation
_____3. Separates solids from liquids by using a porous barrier or filter E
c. evaporation
_____4. Separates iron substances from a mixture A
d. chromatography
_____5. Separates a solid from a liquid by adding heat C
e. filtration
6. Label the following separation techniques and list which type of mixture they are used to separate.
_magnetism__
__evaporation__
__distillation__
___filtration__
_heterogeneous__
_homogeneous_
__homogeneous__
__heterogeneous
Only works for magnetic solid dissolved in liquid
miscible liquids
insoluble solid from liquid
7. Draw the flow chart for removing the individual components of a salt/sand/iron mixture.
MIXTURE OF SAND, SALT, IRON
MAGNETISM
SAND and SALT
Add water
IRON
PEBPEBBLES
FILTRATION
SAND
SALT WATER
EVAPORATION
SALT
8. Define each of the following terms:
a. compound: 2 or more different elements chemically combined. Have different properties than components.
Separated into elements ONLY by chemical means (chemical reactions). Definite composition (constant element
proportion). Represented by a chemical formula
b. element: Building block for everything else. Cannot be broken down or separated by ordinary chemical or physical
means. Represented by chemical symbol.
c. mixture: A physical blend of 2 or more substances. Can be separated by physical means like filtration, distillation, etc.
Individual components keep their identifying properties.
d. homogeneous mixture: Components are uniformly distributed, there are parts but you cannot see them.
Also called solutions.
e. heterogeneous mixture: Not uniform, you can see the parts. Can settle upon standing
f. saturated solution: contains the maximum amount of dissolved solute for a given amount of solvent at a specific
temp and pressure.
g. unsaturated solution: contains less dissolved solute for a given temp and pressure than a saturated solution
h. supersaturated solution: contains more dissolved solute than a saturated solution at the same temp
Must heat a saturated solution, then slowly cool
i. solute: substance that dissolves, present in lesser amount
j. solvent: thing that does the dissolving, present in greatest amount.
k. concentrated solution: solution with a large amount of solute dissolved into it (more solute particles per unit volume)
l. dilute solution: solution with a small amount of solute dissolved into it (fewer solute particles per unit volume)
m. electrolyte: any substance that dissociates and produces ions that conduct electricity. Ex. Salt (solute) dissociates in
water and the solution conducts electricity.
9.
Solution
A
B
Solvent amount (mL)
90
90
Solute amount (g)
10
25
a. After stirring, which solution will be more dilute? ___A_____
b. After stirring, which solution will be more concentrated? ___B_____
c. As the amount of _solute__ in a solution increases, the solution becomes _more______ concentrated.
Problem Solving:
M = moles/Liters
M 1V 1 = M 2V 2
10. What is the molarity of a solution when 3.50 moles of NaCl is dissolved in 2.00 L of solution?
3.5 moles = 1.75 M
M = moles/Liters
2.00L
11. What is the # of moles of solute needed to make a solution that contains 1.53 L of 2.10 M CaCl2?
M = moles/Liters
2.10 M = x
cross multiply and solve for x
1.53L
3.21 mol
12. How many liters of 2.5M NaOH is needed to make 1.25 L of 0.75 M NaOH solution?
M1V1 = M2V2
(2.5 M) (x) = (.75 M) (1.25 L)
combine terms and solve for x
.38 L
13. Calculate the total pressure for a mixture that contains four gases with partial pressures of
5.00 atm, 4.56 atm, 3.02 atm and 1.20 atm.
PT = 5.00 atm + 4.56 atm + 3.02 atm + 1.20 atm
13.78 atm
Solubility:
14. Which substance is the most soluble at 20oC?
KI
15. What is the solubility of NaNO3 in 100 g of water at 30oC?
95 g/100 g H2O
16. If 90.0 g of NH4Cl is added to 100 g of water at 60oC, what type of
solution exists? Saturated, the problem does not indicate that all 90 g
dissolved.
17. How can you identify which substance(s) on the graph are gases?
Negative slopes (lines go down)
18. How many grams of KClO3 will dissolve in 100g of water at 30oC?
10 g
19. What effect does pressure have on the solubility of solids? ____none_____
What effect does pressure have on the solubility of a gas? ____increased pressure increases solubility_________
20. What conditions increase the solubility of a gas dissolved in a liquid?
Increased pressure and decreased temperature
21. What conditions are needed to increase the solubility of a solid dissolved in liquid? Increase the temperature of the
solvent
Use the following particle diagrams to answer questions #22-25.
-
an atom of an element
an atom of a different element
22. Which diagram(s) could represent a mixture? __C, D__
23. Which diagram(s) could represent an element only? ___B___
24. Which diagram(s) represents one single compound? __D____
25. Which diagram(s) represents a mixture of two diatomic molecules? __C____
26. What type of solution is brass: __solid_______ solute in a ______solid_____ solvent
27. What type of solution is air: ____gaseous________ solute in a ____gaseous_______ solvent