Honors Chemistry - Midterm Review

HONORS CHEMISTRY - REVIEW FOR MIDTERM EXAM

Topics to be covered:

I.Introduction

Scientific Method
Metric system
Density
Factor label method for solving problems
Measurements: calculations, significant figures, conversion factors, conversion between units, error analysis
Calculations: moles, molar mass, molar volume, molarity, stoichiometry
Classification of Matter: Elements, Compounds, Mixtures
Physical/Chemical properties/changes

II.Atoms, Molecules and Ions

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History of Atomic Theory: key milestones, persons, and experiments
Atomic structure
Nuclear notations
Average atomic mass
Nuclear stability
Radioactive decay: ,  particles and  ray;  and  decays
Nuclear equations
Half-life, radioactive dating

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III.Electron Configurations

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Waves: main function is to transfer energy, frequency () and wavelength (),  = speed of the wave
Electromagnetic Radiation: no need for medium to travel and constant speed in vacuum,  = speed of light; E = h
Atomic Emission Spectra and the flame test
Bohr’s Model
Duality of electrons, de Broglie
Heisenberg Uncertainty Principle
Schrodinger’s Quantum Mechanical Model: two principles (Pauli Exclusion and Aufbau) and a rule (Hund’s)
Ground state electron configurations, based on which valence shell electron configuration, Lewis dot structure are established

IV.The Periodic Table

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History of development of the Periodic Table
Major features of the Periodic Table: groups/families (names for major groups), periods
Metals, nonmetals, metalloids
Correlations between ground state electron configurations and the Periodic Table: period number and principal energy levels; valence electrons, Lewis dot structures
Octet Rule
Formation of Ions

V. Lab Skill

Bunsen Burner
Safety
Mass and Volume Measurement
Balance
Physical and Chemical Changes
% error
Working with crucibles, evaporating dishes

Review 1

1.A block of material measures 0.20 m by 150. cm by 6.0 mm and has a mass of 2.6 kg. What is its density in g/cm3?

2.24 g of Mg contain 6.02 x 1023 atoms. How many atoms are in 750 mg of Mg?

3.Magnesium, Mg, has a density of 7.25 g/cm3. Given 12.0 cm3 of Mg

a. how many moles of Mg atoms does this represent?( 3.63 mol)

b. how many atoms of Mg are contained in this volume?(2.18 x 1024 atoms)

4.How many molecules of aspirin are contained in a 100.0 mg tablet of aspirin, C9H8O4?(3.34 x 1020 molecules)

5.What is the volume of 1.00x102 g of CH4 gas at STP?( 1.40x102 L)

6.Calculate the density of an unknown object that has a mass of 55 g and occupies a volume of 17 mL.

(3.23 g/mL)

7What is the mass of 2.47 cm3 of platinum? The density of platinum if 22.5 g/cm3.

8.Write formulas for these compounds:

a. sodium carbonate ______c. iron(III) hydroxide ______

b. silicon tetrachloride ______d. ammonium iodide ______

9.Name these compounds:

a. KNO3 ______e. AgF ______

b. CuO ______f. Al2(SO4)3 ______

c. Mg3N2 ______g. H3PO4 ______

d. CCl4 ______h. Ca(OH)2 ______

Review # 2

Complete the work, whenever appropriate, on a separate sheet of paper SHOW all work

1.Make the following conversions:

a. 2.84 kilogram to gram______

b. 544 milliseconds to seconds______

c. 0.0656 gram to milligram______

d. 1102 cm to meters______

e. 3.6 nanometers to meters______

2.Use the factor label method to make each of the following conversions:

a. 5.235 x 10 3ug to mg______

b. 63 dm3 to cm3______

c. 3.9 x 10 5 nm to m______

d. 0.128 L to mL______

e. 18.3 km to cm______

f. 33.4 mg to kg______

3.Compute the density of clay if 42 g occupy 19.1 cm3.

4.What is the number of significant figures in each of the following measurements?

a. 0.558 g ______d. 0.0094 m ______

b. 7.3 m ______e. 19.0000 g ______

c. 410 cm ______f. 75.0 s ______

5.Classify the following properties as physical or chemical.

a. flammability ______

b. electrical conductivity ______

c. ability to displace hydrogen from water ______

d. ability to react with acids ______

6.Classify the following changes as physical or chemical.

a. distillation ______

b. fermentation ______

c. crystallization ______

d. dissolving

7.Element D has oxidation numbers 1+ and 2+. Element E has oxidation numbers 1- and 2-. List the possible formulas of compounds of these elements.

8.Density and speed are expressed in derived SI units. Give these units and tell why they are called derived units.

9.Make the following conversions.

a. 2.52 x 1021 formula units of ZrS2 to moles.______

b. 1.26 x 1025 formula units of Al(CH3COO)3 to grams. ______

c. 6.06 grams of iron(III) sulfate to moles. ______

d. 88.4 grams MnI2 to moles. ______

d. 0.00202 moles of nickel(II) hydroxide to grams. ______

10.Tungsten is Swedish for “heavy stone”. Its symbol, W, comes from wolfram the German name for the element. It has a density of 19.3 g/cm3. How many atoms are in a cubic centimeter of tungsten?

11.Write names for the following compounds:

a. Sr(CH3COO)2 ______

b. Mn(OH)2______

c. CdSO4______

d. Li3N______

e. Th3(PO4)4______

f. Ce2(CO3)3______

12.Write formulas for the following compounds:

a. sodium nitride ______

b. sulfurous acid______

c. cerium(III) sulfide______

d. barium iodate______

e. hydrogen telluride______

f. silver sulfate______

g. hypochlorous acid______

Review # 3

1.The amount of mass per unit volume refers to the

a. densityb. specific weightc. volumed. weight

2.Which f the following is a physical property of sugar?

a. Its composition is carbon, hydrogen, and oxygen.

b. It turns black with concentrated sulfuric acid.

c. It can be decomposed with heat.

d. It is a white crystalline solid.

3.A substance that can be farther simplified may be either

a. an element or a compoundc. a mixture or a compound

b. an element or a mixtured. a mixture or an atom.

4.A substance composed of two or more elements chemically combined is called

a. an isotopeb. a compoundc. an elementd. a mixture

5.An example of a chemical change is the

a. breaking of a glass bottlec. sawing a piece of wood

b. rusting of irond. melting of an ice cube

6.A substance which cannot be farther decomposed by ordinary chemical means is

a. waterb. airc. sugard. silver

7.An example of a physical change is the

a. fermenting of sugar to alcoholc. rusting of iron

b. burning of paperd. dissolving sugar in water

8.Chemical action may involve one of the following except:

a. combining of atoms of elements to form a molecule

b. separation of the molecules in a mixture

c. breaking down compounds into elements

d. reacting a compound and an element to form a new compound and a new element.

10.What is the approximate formula mass of Ca(NO3)2?

a. 70b. 82c. 102d. 150e. 164

11.Which of the following is classified as a diatomic element?

a. waterb. milkc. chlorined. ozone

12.In this reaction XClO3 + A → XCl + O2 + A which substance is the catalyst?

a. Xb. XClO3c . Ad. XCle. O2

13.How many atoms are represented in the formula Ca3(PO4)2?

a. 5b. 8c. 9d. 12e. 13

14.The oxidation number of sulfur in H2SO4 is

a. +2b. +3c. +4d. +6e. +8

15.The present scale of atomic mass is based on 1 amu being equal to the mass of:

a. 1 hydrogen atomc. 1/10 of an oxygen-16 atom

b. 1/12 of carbon-12 atomd. 1/32 of an oxygen molecule

16.If the density of a diatomic molecule of gas is 1.43 g/L, what is its gram-molecular mass?

a. 16 gb. 32 gc. 48 gd. 64 ge. 14.3 g

17.The correct formula for calcium hydrogen sulfate is

a. CaH2SO4b. CaHSO4c. Ca(HSO4)2d. Ca2HSO4e. Ca2H2SO4

18.Which of the following involves a physical change?

a. The formation of HCl and H2 from H2 and Cl2

b. The color change when NO is exposed to air

c. The formation of steam from burning H2 and O2

d. The solidification of corn oil at low temperatures

e. the odor of NH3 when NH4Cl is rubbed together with Ca(OH)2 powder?

19.How many atoms are in one mole of water?

a. 3b. 6.02 x 1023c. 2 (6.02 x 1023)d. 54e. 3 (6.02 x 1023 )

20The Law of Definite Composition is based on definite composition by

a. massb. volumec. densityd. specific mass

e. freezing point and boiling point

21.Which of the following atoms normally forms monatomic molecules?

a. Clb. Hc. Nd. He

23.What is the mass of 1 mole of KClO3 .12 H2O?

a. 132b. 180c. 339d. 516e. 474

24.How many atoms are present on the formula KAl(SO4)2?

a. 7b. 9c. 11d. 12e. 13

26.Which of the following is not a compound?

a. copper sulfateb. carbon dioxidec. sugar

d. aire. lime

27.What volume would 1.5 moles of hydrogen gas occupy at STP?

a. 11.2 Lb. 22.4 Lc. 33.6 Ld. 44.8 Le. 67.2 L

34.One mole of water contains

a. 18 gramsb. 6.02 x 10-23 atoms c. 6 x 1023 ions d. 6.02 x 10-23 molecules

35.A gas at STP which contains 6.02 x 1023 atoms and forms diatomic molecules will occupy

a. 11.2 Lb. 22.4 Lc. 33.6 Ld. 67.2 Le. 1.06 quarts

37.The simplest unit of water that retains its property is called

a. an atomb. an elementc. a protond. a hydroxidee. a molecule

38.The number of atoms of nitrogen represented in the formula NH4NO3 is

a. 1b. 2c. 34. 45. 5

For questions 39-40 : What is the apparent oxidation number of the underlined element in each of the following compounds?

a. +2b. -2c. +3d. -3e. +5

39.NaNO3

40.CaSO4

41.NH3

42.How many grams of sulfur are present in 1 mole of H2SO4?

a. 2b. 32c. 49d. 64e. 98

43.What is the approximate mass of 1 liter of dinitrogen monoxide, N2O, at STP?

a. 1 gb. 2 gc. 11.2 gd. 22 ge. 44 g

45.What is the gram-formula mass of calcium carbonate?

a. 68 gb. 75 gc. 82 gd. 100 ge. 116 g

46.What is the mass in grams of 2.0 moles of NO2?

a. 92b. 60c. 46d. 30

47.Which sample contains a total of 3.00 x 1023 molecules?

a. 14 g N2b. 14 g of Lic. 4.0 g of H2d. 4.0 g of He

50.A Ca (+2) ion differs from a Ca atom in that the Ca ion has

a. more protonsc. more electron b. fewer protonsd. fewer electrons

Review # 4

1.What is the total number of nucleons (protons and neutrons) in an atom of selenium ( at. # = 34; mass # = 79)

a. 34b. 45c. 79d. 113

2.Isotopes of an element have a different

a. number of electronsc. number of protons

b. atomic numberd. mass number

3.A neutral oxygen atom, O, differs from an oxide ion in that the atom has

a. more electronsc. more protons

b. fewer electronsd. fewer protons

4.What is the total number of neutrons in an atom of K, whose mass is 39, and atomic number is 19?

a. 19b. 39c. 20d. 58

5.The amount of hydrogen chloride that the formula HCl represents is one

a. atomb. gramc. literd. molecule

6.The mass number of an atom is equal to the total number of its

a. electrons onlyc. protons only

b. electrons and protonsd. protons and neutrons

7.The number of protons in an atom of Cl - 36 is

a. 17b. 35c. 18d. 36

8.When a chlorine atom reacts with a sodium atom to form an ion, the chlorine atom will

a. lose one electronc. lose two electrons

b. gain one electrond. gain two electrons

9.Element X exists in three isotopic forms. The isotopic mixture consists of 10.0 % X-10, 20.0 % X-11, and

70.0 % X-12. What is the average atomic mass of this element?

a. 11.0 amub. 12.0 amuc. 11.6 amud. 12.4 amu

10.The nucleus of a fluorine atom has a charge of

a. 1+b. 19+c. 9+d. 0

11.The correct formula for nickel (III) sulfate is

a. Ni2S3b. Ni2(SO4)3c. Ni3S2d. Ni3(SO4)2

12.What is the total number of neutrons in an atom of fluorine, whose atomic number is 9 and whose mass is 19?

a. 9b. 19c. 10d. 28

13.Which particle has exactly a mass of approximately 1 mass unit and a unit positive charge?

a. neutronb. electronc. protond. alpha particle

14.When an atom of bromine becomes a bromide ion, its size

a. decreasesb. increasesc remains the same

15.What is the total number of electrons in a magnesium (+2) ion?

a. 10b. 12c. 2d. 24

16.Which species has a negative charge?

a. a lithium ionb. an aluminum ionc. an electrond. a sodium atom

17.Which particle is electrically neutral?

a. protonb. positronc. neutrond. electron

18.An atom that contains 35 protons, 45 neutrons, and 35 electrons has an atomic number of

a. 35b. 45c. 80d. 115

19.Two isotopes of the same element will have the same number of ___.

a. neutrons and electronsc. neutrons and nucleons

b. protons and nucleonsd. protons and electrons

20.,Which sample contains the same number of atoms as 24 grams of carbon?

a. 80. g Arb. 10. g Hec. 24 g Mgd. 4.0 g He

21.How many neutrons are in the nucleus of an atom that has an atomic number of 17 and mass number of 35?

a. 17b. 18c. 35d. 52

22.Isotopes are atoms which have different

a. atomic massesb. atomic numbersc. atomic radiid. number of electrons

23.What is the total charge on anion that contains 10 electrons, 13 protons, and 15 neutrons?

a. -1b. +1c. -3d. +3

24.The element whose properties are most similar to those of tellurium is ______.

a. Beb. Oc. Sd. Po

25.How many electrons are in a neutral atom of Li?

a. 4b. 7c. 10d. 3

26.The number of protons in the nucleus of carbon-13 is

a. 19b. 13c. 7d. 6

27.The mass number of an atom is equal to the total number of its

a. electrons, onlyc. protons, only

b. electrons and protonsd. protons and neutrons

28.Which pair of atoms are isotopes?

12 12 39 38 226 222 39 40

a. 6 C and 7 Nb. 19K and 18 Arc. 88 Ra and 86 Rn d. 19 K and 19K

29.Which set of particles are arranged in order of increasing mass?

a. H2, H, H+b. H+, H, H2c. H2, H+, Hd. H, H+, H2

30.The existence of fractional atomic masses is best explained by the

a. mass of electronsc. existence of isotopes

b. inaccuracies in determining massesd. varying number of protons in the nucleus of the atom

31.Which pair of nuclei contain the same number of neutrons?

a. Li-7 and Be-9b. K - 40 and Ar - 40c. Na -23 and Na-22 d. Na - 23 and Mg -24

32.An atomic mass unit is equal to ____.

a. the mass of a hydrogen atomc. 1/1836 the mass of hydrogen atom

b. the mass of a C-12 atomd. 1/12 the mass of a C-12 atom

33.The mass number of an atom is equal to the total number of its ____.

a. electrons, onlyb. protons, onlyc. electrons and protonsd. protons and neutrons

34.Which atom has a mass of approximately two atomic mass units?

3 2 4 4

a. 1Hb. 1Hc. 2Hed. 2He+2

35.The number of protons in an atom of 17Cl is ____.

a. 17b. 18c. 35d. 36

36.Which nucleus contains a total of 2 protons and 1 neutron?

1 3 3 4

a. 1Hb. 1Hc. 2Hed. 2He

37.What is the mass number of an 1H atom?

a. 1b. 2c. 3d. 4

38.The neutral atoms in a given sample of an element could have different

a. mass numberb. number of protonsc. atomic numbersd. number of electrons

39.The accepted value for the boiling point of a substance is 120 oC. A student performs an experiment and reports the boiling point to be 110 oC. The percent error of the student’s observation is

a. 83%b. 120%c. 20 %d. 80%e. 8.0%

40Which of the following does not have a net charge?

a. a protonb. a neutronc. an electrond. an ione. the nucleus

41.Which of the following pairs show the principle of the Law of Multiple Proportions?

a. H2O(s) and H2O(aq)c. NaCl and KCl

b. N2O and NO2d. C2H5Cl and C2H5Br

42.What is the total number of subatomic particles in an atom having an atomic number of 17 and atomic mass of 35?

a. 17b. 18c. 34d. 35e. 52

43.Which of the following is not part of Dalton’s Atomic Theory?

a. Atoms of a given element have the same mass.

b. All elements are made of indivisible, indestructible atoms.

c. Atoms of one element can be converted into a different element.

d. Compounds are the result of the combination of atoms of different elements.

e. All atoms of a given element are identical.

44.The term nucleon refers to

a. protons, onlyb. neutrons, onlyc. electrons, only

d. both protons and neutronse. both protons and electrons

45.What is the net charge on an atom with 20 protons, 20 neutrons, and 18 electrons?

a. 0b. 2+c. 2-d. 18-e. 20+

Note:

For practice questions regarding electron configurations, and the Periodic Table, review those interactive multiple-choice questions posted on Schoolwire site. Homework assignments are good resource in preparing for the stoichiometry calculations.
Midterm Review: Answer Key

Review 1:

1. 10 g/cm3 (1.4 g/cm3)2. 1.9 x 1022 atoms

7. 55.6 g Pt

8. Na2CO3b. SiCl4c. Fe(OH)3d. NH4I

9. a. potassium nitrateb. copper(II) oxidec. magnesium nitride

d. carbon tetrachloridee. silver fluoridef. aluminum sulfate

g. phosphoric acidh. caclium hydroxide

10. a-Db-Ic-Id-De-constant

Review #2:

1.a. 2840 gb. 5.44 x 10-1 secc. 65.6 mgd. 11.02 me. 3.6 x 10-9 m

2. a. 5.235 mgb. 6.3 x 104 cm3c. 3.9 x 10-4 md. 128 mL

e. 1.83 x 106 cmf. 3.34 x 10-5 kg

3. 2.2 g/cm34. a. 3b. 2c. 2 d. 2e. 6f. 3

5. a. chb. phc. chd. ch6. A. phb. chc. phd. ph

7. DE; D2E; DE28. g/cm3; m/sec9. A. 4.19 x 10-3 molb. 4.27 x 103 gc. 0.0152 mol

d. 0.287 mole. .187 g

10. 6.32 x 1022 atoms11.a. strontium acetateb. manganese(II) hydroxidec. cadmium sulfate

d. lithium nitridee. thorium(IV) phosphatef. cerium(III) carbonate

12. a. Na3Nb. H2SO3c. Ce2S3d. Ba(IO3)2e. H2Tef. Ag2SO4g. HClO

Review #3:

1-a2-d3-c4-b5-b6-d7-d8-b9-b10-e11-c12-c13-e

14-d15-b16-b17-c18-d19-e20-a21-d23-c24-d25-d26-d

27-c34-a35-a36-C3H6O237-e38-b

39-e40-a41-d42-b43-b44-d45-d46-a47-a50-d

Review #4

1-c2-d3-b4-c5-d6-d7-a8-b9-c10-c11-b12-c13-c

14-b15-a16-c17-c18-a19-d20-a21-b22-a23-d24-d25-d26-d

27-d28-d29-b30-c31-d32-d33-d34-a35-a36-c37-a38-a39-e

40-b41-b42-e43-c45-b

22.An analysis of gas gave: C = 85.7%, and H = 14.3%. if the formula mass of this gas is 42 amu, what is the empirical formula and the molecular formula?

a. CH; C4H4b. CH2; C3H6c. CH3; C3H9d. C2H2; C3H6 e. C2H4; C3H6

22-b

28.The empirical formula of a compound is CH. its molecular mass could be:

a. 21b. 40c. 51d. 78

29.The percent by mass of oxygen in MgO is closest to

a. 16%b. 24%c. 40%d. 60%

30.A 20 g of hydrate is heated until all water of hydration is driven off. The mass of the anhydrous compound remaining is 15%. What is the percent of water in the hydrate?

a. 15 %b. 85%c. 1.33%d. 75 %

31.What is the mass in grams of 1 mole of (NH4)2S?

a. 68 gb. 50 gc. 64 gd. 54 g

32.How many molecules are contained in 127 grams of iodine, I2?

a. 1.50 x 1023b. 3.01 x 1023c. 9.03 x 1023d. 12.4 x 1023

33.If the empirical formula for an organic compound is CH2O, then the molecular mass of the compound could be

a. 135b. 60c. 45d. 15

44.If the simplest formula of a substance is CH2 and its molecular mass is 56, what is its true formula

( molecular formula)?

a. CH2b. C2H4c. C3H4d. C4H8e. C5H10

48.A compound contains 0.5 mole of carbon for each mole of hydrogen. The empirical formula of this compound is

a. CHb. CH2c. C2Hd. C2H2

49.A compound has an empirical formula NO2. Its molecular formula could be:

a. NO2b. N2Oc. N4O2d. N4O4

28-d29-c30-85%31-68g32-b 33-b 44-d 48-b49-a

midc_rev.doc: review for chemistry

01/29/2019