Chemistry Final Study Guide-Pre-AP
Name:______
Chemistry Intro., Measurement; Scientific Method (Chpt, 1 and 2)
kiloàhectoàdekaàbaseàdeciàcentiàmilli
1. Convert 6.5 mm to cm = 0.65cm
2. Convert 875mg to kg= 0.000875 kg or 8.75x10-4 kg
3. Write 0.00125 g in scientific notation= 1.25x10-3
4. Write 598,000,000 light years in scientific notation. = 5.98x108
What is the difference between accuracy and precision?
Accuracy: Expt. data compared to true value.
Precision: Comparing expt. trials data with one another.
5. A student weighs a sample three times and gets the following results:
Trial 1: 3.50 g Trial 2: 3.51g Trial 3: 3.53g = Average : 3.51 g
The actual or true value was 4.5 g.
Was the student’s results accurate, precise, or both? Explain. The student’s data is precise but not accurate. The students expt. trials were close to one another, but not close to the true value.
Density= mass divided by volume of a substance
6. What is the density of a 125g sample with a volume of 35mL? = 3.57 g/mL
7. What is the volume of a 50g sample with a density of 2.8 g/mL? = 17.3 mL
8. What are the five steps to the scientific method ?
Five steps: hypothesis, design an expt., perform expt., collect and analyze data, establish a conclusion
9. Determine the number of significant figures in each measurement below.
a. 5.600 g = 4 sig. figs b. 5.09x10-4 g= 3 sig. figs. c. 0.00560g = 3 sig. figs.
10. Calculate and write the answer with the correct number of significant figures.
a. 9.0g + 18.6g + 15g = 43 grams
b. 1.25m x 0.0450m x 2.04m = 0.115m3
Matter and Change (Chapter 3) (Study Matter flow chart)
11. Classify each as a physical change (P) or a chemical change(C).
a. cooking an egg = C d. evaporating water = P
b. burning a match =C e. dissolving sugar in a glass of tea= P
c. crushing a can = P f. animal decomposing =C
12. What is the difference between a substance and a mixture? Substance = element or a compound
Mixture = physical combination of substances, classified as either heterogenous or homogenous
13. Classify each as a substance (S) or a mixture (M).
a. NaCl : S e. tap water = M
b. NaCl solution (NaCl + H2O) = M f. deionized water = S
c. Iron statue = S
d. soil sample= M
14. Classify each as a heterogenous or homogenous mixture
a. Salt water= homo
b. Oil and water = hetero
c. Beef stew= hetero
d. Kool-aid =homo
15. Define shape and volume with each state of matter. (solid, liquid, gas)
State of Matter / Shape / VolumeSolid / definite / definite
Liquid / indefinite / definite
Gas / indefinite / indefinite
Plasma / indefinite / indefinite
16. What is the difference between intermolecular and intramolecular forces?
Intermolecular forces: forces between compounds-à affected during physical changes
Intramolecular forces: forces that hold elements together in a compound-à affected during chemical changes
17. What happens to the intermolecular forces and kinetic energy during each phase process below.
Kinetic Energy Intermolecular Forces
a. Freezing Decreases Increases
b. Evaporation Increases Decreases
c. Condensation Decreases Increases
d. Sublimation Increases Decreases
e. Deposition Decreases Increases
Atomic Structure: (Chapter 4)
18. What is Dalton’s Atomic Theory? Used scientific method to validate the nature of an atom: Most of the theory is still believed to be true except that conclusion that atoms are indivisible . We now know that atoms can be subdivided into smaller particles: protons, electrons, and neutrons.
19. Complete the table on atomic subparticles.
Subparticle / Atom’s Location / Charge / Massproton / nucleus / + / 1 amu
neutron / nucleus / neutral / 1 amu
electron / Electron cloud / - / approximately 0 amu
20. Complete the table on atomic subparticles.
Element Symbol / Atomic # / Mass # / # of p+ / # of n0 / # of e-Be / 4 / 9 / 4 / 5 / 4
Ag1+ / 47 / 107 / 47 / 60 / 46
Mg2+ / 12 / 25 / 12 / 13 / 10
P / 15 / 31 / 15 / 16 / 15
N3- / 7 / 14 / 7 / 7 / 10
21. Classify the type of ion Mg2+ and N3- are ? Mg2+ = cation ; N3- = anion
22. Iodine has three isotopes
I-127 has a natural abundance of 80%
I-126 has a natural abundance of 17%
I-128 has a natural abundance of 3%
a. What is the atomic number for Iodine? = 53
b. Complete the table for each iodine isotope.
Iodine’s Isotopes / # of protons / # of electrons / # of neutronsI-126 / 53 / 53 / 73
I-127 / 53 / 53 / 74
I-128 / 53 / 53 / 75
c. What is a similarity and a difference between iodine’s isotopes? Same number of protons, but different number of neutrons which explains why they have different mass numbers.
d. Calculate the atomic mass of Iodine. = 126.8 amu
23. What is the difference between mass number and atomic mass?
Mass number: mass of an individual atom
Atomic mass: the average mass of an element due to the isotopes they have.
Periodic Table (Chapter 6)
24. How is the modern periodic table arranged? Increasing atomic number
25. Give me an example of a metal, non-metal, and a metalloid.
Most metals are to the left of the stair cases, while non-metals are to the right (except H). Metalloids fall along the stair case, except Al and Po, which are both classified as metals.
26. Classify each property below as a metal (M) or non-metal (NM)
a. Brittle: NM b. conductors: M b. insulators: NM d. malleable: M
e. low melting point: NM f. high melting point: M g. high density: M f. low density: NM
27. Distinguish between representative elements and transitional elements. Give an example of each.
Representative elements are the tall groups on the periodic table, whereas the transitional elements are in the short groups.
28. What element is in period 4, group 6? Cr
29. What are valence electrons? Electrons in the outer most energy level. Responsible for the chemical nature of the element.
30. How many valence electrons does group 3 have? 2 ve- Group 17 have? 7 ve-
31. Which group of elements is consider to be the most stable and why? Noble gases, maximum number of ve-
32. a. What type of ion does a metal become to reach stability? Cation, will loose enough ve- to fall back onto a lower energy level that is filled.
b. What type of ion does a non-metal become to reach stability? Anion, will gain enough ve- to reach maximum stability, fill-up the energy level it is on.
33. a. What is atomic radius? Size of an atom.
b.Use the graph below to explain the periodic trend for atomic radius across a period and down a group.
Across a period: Atomic radius decreases because nuclear energy increases. The protons attraction for the ve- increases, causing the atom to shrink.
Down a group; Atomic radius increases because nuclear energy decreases due to the shielding affect and distance from the ve-.
34. a. What is ionization energy? The amount of energy needed to remove a ve- from an atom.
b
Use the graph above to explain the periodic trend for ionization energy across a period and down a group.
Across a period: Ionization energy increases because nuclear energy increases making it harder to remove a ve- from an atom.
Down a group: Ionization energy decreases because the nuclear energy decreases making it easier to remove a ve- from an atom.
35. a. Rank the elements below from largest to smallest in size. (pg. 175 data table)
Li, Li1+, F, F1-
largest Li, F1- , F, Li1+ smallest
(size ) (size)
Electron Properties and Arrangement (Chapter 5)
36. Electrons have similar properties to light particles because they are both very tiny in size and travel extremely fast. An electromagnetic spectrum breaks light particles into different regions based on the following properties: frequency, wavelength, and energy. Use the table below to answer the following questions.
a.What happens to frequency when energy increases? Frequency increases too, direct relationship
b.What happens to energy when wavelength increases? Energy decreases, inverse relationship
c.What happens to wavelength when frequency decreases? Wavelength increases, inverse relationship
37. T or F Each period on the periodic table represents an energy level? True
38. What is the maximum number of electrons on the 3rd energy level? 2n2 rule: (n= energy level) = 18 e-
39. Draw the four type of orbitals that electrons can move around in. s-orbital (spherical), p-orbital(pair shaped), d-orbital(daisy), f-orbital(flower or fireworks)
40.What orbitals are present on the second energy level? 2 orbitals, s and p
41.What is the electron configuration (arrangement) of oxygen, iron, and bromine?
O: 1s22s22p4 (2 unpaired electrons in the 2p-orbitals)
Fe: 1s22s22p63s23p64s23d6 (4 unpaired electrons in the 3d-orbitals)
Br: 1s22s22p63s23p64s23d104p5(1 unpaired electron in a 4p-orbital)
42.How many unpaired electrons does iron have in its electron configuration? Fe has 4 unpaired electons in the d-orbital.
Chemical Bonding and Naming (Chapter 7-9)
43. What is some similarities and differences between ionic and covalent compounds. (Drawing a Venn Diagram might be helpful).
Ionic Cmpds: Transfer of ve- between atoms producing ions, larger difference in electronegativity between elements, usually between a metal ion (cation) and a non-metal ion (anion). Polyatomic ions are present in a compound.
Covalent or Molecular Cmpds: Sharing of ve- between atoms, smaller difference in electronegativity between atoms, between non-metal atoms, diatomic molecules, polar vs. non-polar molecules.
44. Classify the following as either ionic or covalent (molecular). *Nomenclature Flow Chart/Study polyatomic ions
a. CaCl2 = Ionic b. CO2=Covalent c. K3(PO4) = Ionic d. SO3 = Covalent e. O2 = Covalent f. Pb3N2= Ionic g. (NH4)2(SO3) = Ionic
b.Write the chemical names of the compounds listed in question 43.
a. calcium chloride
b. carbon dioxide
c. potassium phosphate
d. sulfur trioxide
e. oxygen (diatomic molecule-know other six)
f. lead(II) nitride
g. ammonium sulfite
45. Write the chemical formula for each of the following compounds.
· sulfur hexafluoride = SF6
· lithium nitride = Li3N
· chromium (III) carbonate
· tin(II) chloride= SnCl2
· ammonium acetate= NH4 (C2H3O2)
· bromine = Br2
Chemical Reactions (Chapter 10) and Nuclear Reaction (Chpt. 25)
46.Classify and balance the following chemical reactions.
a. 2H2O -----> 2H2 + O2 : Decomposition
b. CH4 + 2O2 ----> CO2 + 2H2O : Combustion
c. 3O2 + 2KCl -----> 2KClO3 : Combination or Synthesis
d. 3Na(OH) + FeBr3 ----> 3NaBr + Fe(OH)3 : Double Replacement
47.What are some similarities and differences between chemical and nuclear reactions?
(Venn Diagram)
Chemical Reactions: Stabilizes the e-cloud; rate of reactions can vary due to temp. catalysts, inhibitor, concentration and size of reactants, deals with changes valence electrons, exothermic and endothermic reactions.
Nuclear Reactions: Stabilizes the nucleus, deals with changes in ratio of neutrons to protons, rate of reaction usually constant which is why scientist can determine a half-life of radiosotopes, usually only exothermic reactions, more exothermic than chemical reactions.
Similarities: To stabilize the atom; exothermic reactions
48. What is the symbol and charge for alpha, beta, and gamma radiation?
Alpha: He-4 or α; positive charge particle
Beta: e- or β; negative charge particle
Gamma: ϒ; neutral particle
49. If beta was placed in an electrical field would its pathway change? If so, would it bend near the positive magnet or the negative magnet? Explain. Yes, because it has a negative charge it would bend towards the positive plate (opposite charges attract one another
50. Complete the nuclear equations:
a. K -----> e + ______= Ca-40 (beta reaction)
b. Pu ------> He + ______= U-238 (alpha reaction)
c. ___= U-239 ------> He + Th (alpha reaction)
51. What is a radioisotope? An atom with an unstable nucleus (ratio to p+ to n0 is imbalanced)
52. Using the band of stability graph, determine which of the following isotopes are classified as radioisotopes?
a. N-14 (no) b. Ba-112 (yes) c. Th-240(yes) d. Sn-110 (no)
53. a. What is the half-life for a radioisotope? The time it takes for half of the parent isotope sample to decay by half.
b. If we start with a 175 gram sample of Thorium-134, how much will be left after three half-lives. The half-life of T-134 is 24.1 days. = 21.88 grams
54. Use the radioactive decay graph to answer the following questions.
a. Label the line that represents the parent and daughter isotope.
b. How much of the parent isotope is left over when 0.85 of the sample has decayed into the
daughter isotope? = 0.15
c. At what half-life is the daughter isotope fraction equal to 0.65. = 1.5
Chapter 10: Chemical Quantities
55. What is the mole conversion used to convert to representative particles of a substance?
1 mole of a substance = 6.02x1023 representative particles of that substance.
56. What is the mole conversion used to convert to mass of a substance.
1 mole of a substance = the molar mass of that substance
57. Identify what type of representative particle (atom, ionic compound, molecule) represents each substance below.
a. H2O = molecule B. MgCl2 = ionic compound c. Br2 = molecule d. Fe = atom
58. Convert 6.32x1020 atoms of Fe to moles of Fe. =1.05x10-3 or 0.00105 moles of Fe