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Chemistry Spring Final Review 2010-2011
Alchemy Unit
1. Define matter. Matter is anything that has mass (weight), volume (takes up space), and exists in
the known universe.
2. What is the density formula? What is the density of a coin with a mass of 5.5 grams and volume of
26.1 mL? D=m/v
5.5g/26.1mL = 0.21 g/mL
3. What lab equipment do I use to measure mass, take the volume of liquids, and heat substances?
A scale or balance measures mass. A graduated cylinder measures the volume of liquids. A
Bunsen burner and hot plate heat substances.
4. What would you observe for H2O(s), H2O(l), H2O(g), and NaCl (aq)?
I would observe ice, water, steam (water vapor), and salt water (salt dissolved in water).
5. Using the periodic table, where are the metals and nonmetals? What is hydrogen?
Metals are on the left side and the nonmetals are on the right side. Hydrogen, although on the left
side of the periodic table, is an nonmetal.
6. Where are the alkali, alkaline earth, transition metals, halogens, and noble gases?
Alkali metals = group 1, alkaline earth metals = group 2, transition metals are in the middle of the
periodic table, halogens = group 7, noble gases = group 8
7. On the periodic table, what are the trends for atomic mass and reactivity as you move across a
period and down a group?
The atomic mass increases as you move across (right) the rows and down a group on the periodic
table. Reactivity increases down a group for metals and up a group for nonmetals.
8. a). What are valence electrons? Valence electrons are the electrons on the outermost shell.
b). How many valence electrons do Mg, S, and Al have? Mg =2, S=6, Al=3
9. In ionic bonds, metals tend to lose electrons and nonmetals gain electrons. What happens to
these elements to achieve noble electron configuration?
a). oxygen b). chlorine c). sodium d). barium
a) gains 2 electrons b) gains 1
c) loses 1
d) loses 2
10. What is the chemical formula of the compound formed when beryllium reacts with fluorine? When
potassium reacts with sulfur? BeF2 and K2S
Smells Unit
11. What is the HONC1234 rule? Draw the Lewis Dot structures for the following molecules.
a). OCl2
b). SiI4
b)
..
a)
:I:
.. .. ..
:I:Si:I:
˙˙ ˙˙ ˙˙
..
..
..
:Cl:O:Cl:
˙˙
˙˙
˙˙
:I:
˙˙
12. What is the difference between lone pairs and bonded pairs? How many lone pairs and bonded
pairs are on the molecules in question 11? Lone pairs of electrons are paired electrons that are
from one atom. Bonded pairs of electrons are electrons shared between by two atoms. Question
11a) has 12 lone pairs and 4 bonded pairs. Question 11b) has 8 lone pairs and 2 bonded pairs.
13. Write the molecular formula, structural formula, Lewis Dot structure, and ball-and-stick formula for
water.
Molecular formula
H2O
Structural Formula
Lewis Dot Structure
Ball and Stick Model
14. What is electronegativity? Where are the most and least electronegative elements?
Electronegativity is the attraction of bonded electrons by an atom. The most electronegative
elements (polar bears) are located on the top, right (nonmetals) of the periodic table. The least
electronegative elements (metals) are located at the bottom left of the periodic table.
15. How does the electronegativity difference determine nonpolar covalent, polar covalent, and ionic
bonds? What are happening to the electrons in these different bonds?
Nonpolar covalent bonds have electronegativity difference (ED) between two atoms at 0-0.5 and
there is equal sharing of electrons.
Polar covalent bonds have ED between 0.51-2.1 and there is unequally sharing of electrons.
Ionic bonds have ED 2.1 or higher and there is losing and gaining of electrons.
Toxins Unit
16. What are the chemical formula of the following polyatomic ions and their charges?
a). sulfate SO4 -2b) sulfite SO3 -2
c) hydroxide OH-1 d) nitrate NO3 -1
e) nitrite NO2 -1
17. What are the four types of chemicals reactions we have learned? Give an example of all four
types.
Combination reaction
A + B → AB
Decomposition reaction
AB → A + B
Single Displacement
AB + C → CB + A
Double Displacement
AB + CD → CB + AD
18. Name the type of chemical reaction and balance the equation.
a. ____ S8 + ___12_O2  __8__ SO3 Combination reaction
b. __2__ NaBr + ____ CaF2  __2__ NaF + ____ CaBr2 Double displacement reaction
19. Complete the following reactions and then balance them.
a. Sr + 2HCl → ____H2__ + ____SrCl2___ Single displacement reaction
b. ZnF2 + 2NaNO3 → ____2NaF__ + __Zn(NO3)2_____Double displacement reaction
c. H2SO4 + BaI2 → ___2HI___ + ___BaSO4_____Double displacement reaction
d. Ca(OH)2 + 2 Li → ____Ca__ + ___2LiOH____Single displacement reaction
20. Answer the following questions about a mole.
a. How many atoms are in 1 mole of Cu, copper? 6.02x1023 atoms Cu
b. How many molecules are in 0.5 mole of H2O, water? 6.02x1023 x 0.5 = 3.01x1023
molecules H2O
21. What is the molar mass of Al2(SO4)3? 342.17 g/mol
22. Answer the following questions about the relationship between mole and mass.
a. a. How many moles are in 2.5 grams of H2O, water?
2.5 g H2O x 1 mole =
18.02g
0.14 mole H2O
b. How many grams are 0.75 moles of H2O, water?
0.75 moles H2O x 18.02 g = 13.5 g H2O
1 mole
Use the following combustion reaction with propane, C3H8, to answer the following stoichiometry
questions.
C3H8+ 5O2 → 3 CO2 + 4H2O
23. 10. How many moles of O2, oxygen, will produce 2.5 moles of H2O, water?
2.5 moles H2O x 5 moles O2 = 3.1 moles O2
4 moles H2O
24. How many grams of O2, oxygen, will be needed to react 1.50 moles of C3H8, propane?
1.50 moles C3H8 x 5 moles O2 x 32g O2 = 240.g O2
1mole C3H8
1 mole O2
25. How many moles of H2O, water, will be produced if there is 25.0 grams of CO2, carbon dioxide
gas?
25.0g CO2 x 1 mole CO2 x 4 moles H2O = 0.757 moles H2O
44.01 g CO2
3 moles CO2
26. How many grams of C3H8, propane, are needed to produce 175 grams of CO2, carbon dioxide
gas?
175g CO2 x 1 mole CO2 x 1 mole C3H8 x 44.11g C3H8 = 58.5 g C3H8
44.01g CO2
3 moles CO2
1 mole C3H8
27. How do you neutralize an acid? You can neutralize with a base.
28. Find the pH of each solution and determine if it is an acid, base, or neutral substance.
a). a). [H+] = 0.0001 M pH=4 Acid
b). [OH-]= 0.000001 M pH= 8 Base
c).[H+] = 1.0 x 10 -3 M pH=3 Acid
d). [OH-] = 1.0 x 10 -9 M pH=5 Acid
e) pOH= 3.5 pH=10.5 Base
f) pOH= 7.7 pH=6.3 Acid
29. Define a solute, solvent, and solution. A solute is the substance of lesser amount that is being
dissolved. The solvent is the greater amount substance (usually a liquid) in which the solute is
dissolved into. A solution is when a solute is completely dissolved and dispersed in a solvent. For
example, salt (solute) dissolves in water (solvent) to make a solution of salt water.
30. How many moles of vinegar are in a 0.67M solution that is 1.2 L in volume?
Use molarity triangle for the questions #7-10.
0.67 x 1.2 L = 0.80 moles vinegar
31. What is the molarity of a solution of 2.8 moles nitric acid prepared in 250 mL water?
250mL ÷ 1000 = 0.25 L
2.8 moles ÷ 0.25 L = 11 M nitric acid
32. If you have 35g NaCl dissolved in 750 mL of water, what is the molarity?
750mL ÷ 1000 = 0.75 L
35g ÷ 58.44 g/mol NaCl = 0.5989 moles NaCl
0.5989 moles ÷ 0.750 L = 0.79854 ≈ 0.80 M NaCl
33. 45g of Ca(OH)2 was used to make a 2.0M solution. How much water was used?
45g ÷ 74.10 g/mol Ca(OH)2 = 0.60729 moles Ca(OH)2
0.60729 moles ÷ 2.0 M = 0.30 L Ca(OH)2
Weather Unit
34. How do you convert from Celsius to Kelvin temperature? Then solve the following temperature
conversions.
a. 25 °C = ___298___K
b. 110 °C = ___383___K
Pressure Conversion units
1 atm = 101.3 kPa = 101,325 Pa = 760 mm Hg = 760 torr = 14.7 lb/in 2 (psi)
35. The air pressure inside a submarine is 0.54 atm. What would be the height in millimeters of
mercury (Hg) by this pressure? 0.54 atm x 760 mmHg = 410 mmHg
1 atm
36. The pressure gauge on a compressed air tank reads 43.2 lb/in 2. What is the pressure in torr?
43.2 psi x 760 torr = 2233 ≈ 2230 torr
14.7 psi
37. What are Boyle’s Law, Charles’ Law, Gay-Lussac’s Law, and the combined Gas Laws?
For a fixed amount of gas, the pressure is indirectly related to volume at constant temperature. P 1V1=
P2V2 (Boyle’s Law).
For a fixed amount of gas, the volume is directly related to the temperature when pressure is
constant. V1/ T1= V2/T2 (Charles’ Law).
For a fixed amount of gas, the pressure is directly related to the temperature when volume is
constant. P1/ T1= P2/ T2 (Gay-Lussac’s Law).
*** Remember the relationship graphically too.***
38. At constant temperature, what will happen to pressure if the volume is decreased? What gas law
does this represent?
Pressure will increase according to Boyle’s Law.
39. At constant volume, what will happen to pressure if
Pressure will increase according to Gay-Lussac’s Law.
40. At constant pressure, what will happen to the volume of the temperature decreased? What gas
law does this represent?
Volume will decrease according to Charles’ Law.
Use Charles’, Boyle’s, Gay-Lussac’s, and Combined Gas Law to solve the following problems.
41. A balloonist puts 63,000.0 liters of air into her balloon at 32.0°C. The air in the balloon is heated to
275°C. What is the final volume of the air in the balloon?
63,000L = V2
V2= 113,193 L
32 + 273
275 + 273
42. At 2.0 atm of pressure, the volume of a balloon is 0.40 L. Assuming that the temperature
remains constant, what will the volume of the balloon be at 1.7 atm of pressure?
(2.0 atm) (0.40 L) = (1.7 atm) V2
V2 = 0.47 L
43. At 300 K, the pressure inside a rigid can is 2.2 atm. If the temperature increases to 315K, what is
the pressure inside the can?
2.2 atm =
300K
P2
P2 = 2.3 atm
315K
44. What is the final volume of a 400.0 mL gas sample that is subjected to a temperature change
from 22.0 °C to 30.0 °C and a pressure change from 760.0 mm Hg to 360.0 mm Hg?
760.0 mmHg (400.0 mL) = 360.0 mmHg V2
22 + 273
30 + 273
V2 = 867.3 mL
45. What is STP? Standard Temperature and Pressure of O ºC and 1 atm.
46. How many liters does 3 moles of chlorine gas occupy?
3 moles x 22.4 L = 67.2 L chlorine gas
1 mole
47. How many moles does 55.0 liters of hydrogen gas occupy?
55.0 L x 1 mole = 2.46 moles of hydrogen gas
22.4 L
48. How many atoms do 125 liters of helium gas?
125 L x 1 mole x 6.02 x 10 23 atoms = 3.36 x 1024 atoms helium gas
22.4 L
1 mole
49. How many liters are in 1.25x1024 atoms of neon gas?
1.25x 1024 atoms x 1 mole
x 22.4 L = 46.5 L neon gas
23
6.02 x 10 atoms
1 mole
Fire Unit
50. What are endothermic and exothermic processes? An endothermic process has a negative ΔT
and heat is absorbed from the environment to the substance. An exothermic process has a positive
ΔT and heat is released from the substance to the environment.
51. Which requires more heat? A) Heating 50g water 20°C-40°C OR B) Heating 30g water 20°C-50°C
A) Q=(50g)(20˚C)(1cal/g˚C) = 1000 cal B) Q=(30g)(30˚C)(1cal/g˚C)= 900 cal
52. Which cup of water gets the hottest?
A) 350 calories transferred by 50g water starting at 30°C Q/mxC = ΔT, 350/50x1= ΔT, ΔT=7˚C
B) 500 calories transferred by 80g water starting at 30°C 500/80x1 =ΔT, ΔT= 6.25˚C
53. What will extinguish a fire? A fire can be extinguished by inhibiting oxygen (fire blanket) or
covering it with noncombustible substance like water, carbon dioxide, sand, etc.
54. Which the following will combust? A) H2O
b) CO2
C) NaCl
D) Mg
E) CH4
55. A 4g marshmallow is burned completely warming 300mL water. The temperature of the water is
raises 20°C to 60°C.
a) How many calories of heat were transferred to the water?
Q= (300g water)(40˚C)(1cal/g˚C)= 12,000 cal
b) Calculate the calories per gram of marshmallow.
12,000cal ÷ 4g marshmallow = 3,000 cal/g
c) How many food Calories does one marshmallow have?
12,000 cal ÷ 1,000 = 12 Food Calories
** Chemical Equilibrium will be reviewed in class.