Chem 1113 Exam 1, 2, and 3

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For an element with the Lewis symbol :X: , choose the appropriate number of valence electrons present from the response list. 4 valence electrons 1 valence electron 7 valence electrons 3 valence electrons

4 valence electrons

How many molecules of CO2 are present in 33.6 g of CO2? 4.60 × 10^23 1.27 × 10^-24 7.22 × 10^23 8.90 × 10^26

4.60 × 10^23

Which of the following mathematical expressions is correctly evaluated? no correct response. more than one correct response. (10^3)/(10^4) = 10^-7. (10^3)/(10^-4) = 10^7. 10^3 × 10^4 = 10^12.

(10^3)/(10^-4) = 10^7

For the indicated element, select the correct oxidation number from the response list: oxidation number of Fe in Fe2O3. +2 +3 +4 +6

An atom contains 33 protons, 35 neutrons and 33 electrons. The atomic number and mass number for this atom are, respectively, 35 and 33. 35 and 68. 33 and 68. 33 and 35.

33 and 68

Which of the following solutions has an osmolarity of 0.30? 0.10 M CaCl2 0.10 M glucose 0.20 M NaCl 0.30 M NaCl

0.10 M CaCl2

Choose the correct numerical value for the molarity from the response list for a solution prepared from 0.40 mole solute in 2.0 L of solution. 0.10 M 0.20 M 1.0 M 2.0 M

0.20 M

Calculate the grams of NaOH present in 9.0 mL of a 8.0% (m/v) NaOH solution. 0.72 g 0.80 g 7.2 g 8.0 g

0.72 g

Elements in groups IA and VIIA of the periodic table possess, respectively, how many valence electrons? 1 and 1 7 and 1 1 and 7 8 and 8

1 and 7

The "mathematical meaning" associated with the metric system prefixes centi, milli, and micro is, respectively, 10-3, 10-6, and 10-9. 10-2, 10-4, and 10-6. 10-3, 10-9, and 10-12. 10-2, 10-3, and 10-6.

10-2, 10-3, and 10-6.

What is the uncertainty associated with the measurement of 6.02 x 10^4? 0.01 10 100 0.1

100

The formula mass of ammonium phosphite, (NH4)3PO3, is..... 153.11 amu 133.09 amu 125.01 amu 97.01 amu

133.09 amu

Using the balanced equation for the combustion of ethane: 2C2H6 + 7 O2 → 4CO2 + 6H2O, how many moles of O2 that react with four moles of C2H6? 8 14 6 7

The correct electron configuration for 17Cl is...... 1s^2 2s^2 2p^5. 1s^2 2s^2 2p^6 3s^2 3p^5. 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^5. 1s^2 2s^2 2p^6 3s^2.

1s^2 2s^2 2p^6 3s^2 3p^5

Choose the appropriate electron configuration for an element with no unpaired electrons. 1s^2 2s^2 2p^6 3s^2 3p^6. 1s^2 2s^2 2p^6 3s^1. 1s^2 2s^2 2p^6 3s^2 3p^4. 1s^2 2s^2 2p^5.

1s^2 2s^2 2p^6 3s^2 3p^6

Which set of coefficients balances the equation C4H10 + O2→ CO2 + H2O? 1, 3, 4, 5 1, 7, 4, 5 2, 13, 8, 10 1, 6, 4, 5

2, 13, 8, 10

Which of the following measured numbers has an uncertainty of 0.01 associated with it? 32.930 3.0 × 10^-1 no correct response more than one correct response 3.02 × 10^6

3.0 × 10^-1

In which one of the following measure numbers are all of the zeros significant? 3,300,000 0.0705 0.000440 3.945900

3.945900

Calculate the concentration in % (m/m) of a solution containing 20.5 g of LiF dissolved in 340.0 g of H2O. 1.14% (m/m) 5.69% (m/m) 6.03% (m/m) 6.42% (m/m)

5.69% (m/m)

Which of the following elements is both a metal and a representative element? 92U 9F 50Sn 79Au

50Sn

How many electrons appear in the Lewis symbol for an element whose electron configuration is 1s^2 2s^2 2p^4? 2 4 6 8

A mole of a chemical substance represents..... the mass of the substance that will combine with 12.0 g of carbon. 6.02 × 10^23 chemical particles of the substance. 6.02 × 10^-23 grams of the substance. the mass of the substance that will combine with 100.0 g of oxygen.

6.02 × 10^23 chemical particles of the substance.

For the electron configuration 1s^2 2s^2 2p^6 3s^2 3p^5, choose the appropriate number of valence electrons present from the response list. 7 valence electrons 1 valence electron 3 valence electrons 5 valence electrons

7 valence electrons

If the temperature of an object is 435oC, what is the temperature on a Kelvin scale? 608 K 162 K 708 K 672 K

708 K

The measurement 8310.90 expressed in scientific notation becomes...... 8.3109x10^3 0.83109x10^3 8.3109x10^2 8.3109x10^4

8.3109x10^3

In which of the following molar quantities of sulfur would 5.95 × 10^24 atoms of sulfur be present? 9.79 moles S 9.88 moles S 9.69 moles S 9.99 moles S

9.88 moles S

To determine the formula mass of a compound you should: Add up the atomic masses of all the atoms present. Add up the atomic masses of all the atoms present and divide by the number of atoms present. Add up the atomic numbers of all the atoms present and divide by the number of atoms present. Add up the atomic numbers of all the atoms present.

Add up the atomic masses of all the atoms present.

If object A weighs 6.0 grams and has a volume of 3.0 mL and object B weighs 9.0 grams and has a volume of 2.25 mL...... B is less dense than A. B is four times as dense as A. B is twice as dense as A. A and B have equal densities.

B is twice as dense as A.

Which of the following statements is correct? Compounds, but not elements, are pure substances. Neither elements nor compounds are pure substances. Elements, but not compounds, are pure substances. Both elements and compounds are pure substances.

Both elements and compounds are pure substances.

Which of the following ions does not have the same electron configuration as the noble gas neon? C4+ N3- Na+ F-

C4+

Given the following electronegativities: Na = 0.9, H = 2.1, Cl = 3.0 which of the following statements is true? HCl is a nonpolar covalent compound and Cl2 is a polar covalent molecule. Cl2 is a nonpolar covalent molecule and HCl is a polar covalent molecule. NaCl is a polar covalent compound and HCl is an ionic compound. H2, Cl2, and HCl are polar covalent molecules.

Cl2 is a nonpolar covalent molecule and HCl is a polar covalent molecule.

Which of the following statements contrasting covalent bonds and ionic bonds is correct? Covalent bonds usually involve a metal and a nonmetal and ionic bonds usually involve two nonmetals. Covalent bonds usually involve two nonmetals and ionic bonds usually involve a metal and a nonmetal. Covalent bonds usually involve two nonmetals and ionic bonds usually involve two metals. Covalent bonds usually involve two metals and ionic bonds usually involve a metal and a nonmetal.

Covalent bonds usually involve two nonmetals and ionic bonds usually involve a metal and a nonmetal.

Which of the following molecular compounds would have a Lewis structure that contains 10 electron dots? HCN H2O NH3 CO2

HCN

Which of the following statements concerning Avogadro's number is correct? It denotes the number of molecules in one mole of any molecular substance. It has the value 6.02 × 10-23. It denotes the number of atoms in one mole of any substance. It is the mass, in grams, of one mole of any substance.

It denotes the number of molecules in one mole of any molecular substance.

Which of the following is the correct equilibrium constant expression for the reaction 4HCl (g) + O2 (g) <> 2H2O (g) + 2Cl2 (g) Keq = [Cl2][H2O]/[HCl][O2] Keq = [HCl][O2]/[Cl2][H2O] Keq = [Cl2]^2[H2O]^2/[HCl]^4[O2] Keq = [HCl]^4[O2]/[Cl2]^2[H2O]^2

Keq = [Cl2]^2[H2O]^2/[HCl]^4[O2]

In which of the following pairs of compounds are both members of the pair ionic compounds? H2S and NCl3 LiI and NiO LiF and H2O PI3 and HBr

LiI and NiO

For the ion or element combinations of M2+ and X2-, choose the correct formula for the compound produced. M2X M2X3 MX2 MX

Choose the correct formula of the compound formed when M, which has two valence electrons and X, which has seven valence electrons are combined. M2X3 MX2 M2X MX

MX2

In which of the following pairs of properties are both properties physical properties? More than one correct response. No correct response. Melts at 73°C, decomposes upon heating. Is a good reflector of light, is blue in color. Has a high density, is very hard.

More than one correct response

For which of the following pairs of elements would the compound formed between them most likely be a molecular compound? Ba and O N and S Cs and F Li and Br

N and S

In which of the following pairs of chemical formulas do both formulas represent compounds? O2 and O3 N2O4 and NO2 CO2 and O2 HCN and N2

N2O4 and NO2

In which of the following molecular compounds are all the bonds single bonds? CS2 O2 NBr3 CS

NBr3

The correct formula for the ionic compound that might be formed between Na and As is...... Na3As Na2As3 NaAs3 Na3As2

Na3As

Which of the following is a property of both the liquid state and the solid state? more than one correct response. an indefinite volume. a definite shape. no correct response. an indefinite shape and a definite volume.

No correct response

For the set of ionic compounds, BaSO4, BaCO3, Ba(OH)2, choose the correct characterization of their solubilities in water from the response list. All three salts are soluble. Two of the three salts are soluble. One of the three salts is soluble. None of the three salts are soluble.

One of the three salts is soluble.

Characterize EACH of the following statements as being TRUE or FALSE and then indicate the collective true-false status using the choices provided. (1) An electron configuration specifies subshell occupancy for electrons. (2) The atomic number is double the mass number for atoms that contain an equal number of protons and neutrons. (3) All occupied orbitals are completely filled in atoms of the element neon, which contains a total of 12 electrons. None of the statements is true. Two of the three statements are true. Only one of the statements is true. All three statements are true.

Only one of the statements is true

Use the following to answer the questions below: In each of the following multiple-choice questions, characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices a) All three statements are true. b) Two of the three statements are true. c) Only one of the statements is true. d) None of the statements are true. Characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices. (1) Oxidation and reduction are complementary processes that always occur together. (2) For a system at chemical equilibrium, decreasing the concentration of a reactant will always shift the equilibrium to the right. (3) The reactants in a combination reaction must be elements. All three statements are true. Two of the three statements are true. Only one of the statements is true. None of the statements are true.

Only one of the statements is true.

Which of the following substances is both homoatomic and tetraatomic? P4 HCN H2O2 H2CO3

Which of the following changes is a chemical change? More than one correct response. Pulverizing of hard sugar cubes. Rusting of iron. No correct response. Melting of ice.

Rusting of iron

Consider the following redox equation: SO2 + NO2 → SO3 + NO. Choose an appropriate chemical formula from the list that identifies the reducing agent. SO2 SO3 NO NO2

SO2

Which of the following statements concerning redox reactions is incorrect? The oxidizing agent is the substance reduced. The reducing agent is the substance oxidized. The oxidizing agent loses electrons. The substance oxidized loses electrons.

The oxidizing agent loses electrons.

Use the following to answer the question below:In the following multiple-choice question, characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices. a) All three statements are true. b) Two of the three statements are true. c) Only one of the statements is true. d) None of the statements is true. Statements: (1) A molecule is a group of two or more atoms that functions as a unit because the atoms are bound together by chemical forces. (2) The crushing of ice to make ice chips is a physical procedure that involves a chemical change. (3) Most naturally occurring samples of matter are mixtures rather than pure substances. Only one of the statements is true. All three statements are true. Two of the three statements are true. None of the statements is true.

Two of the three statements are true.

For the following general reaction equation, choose the correct form of the equilibrium constant expression from the response list: 2X (g) + 3Y (g) <> 2Z (g) [Z]^2 [Z]^2/[x]^2 [Z]^2/ [x][y] [Z]^2/ [x]^2[y]^3

[Z]^2/ [x]^2[y]^3

The Roman numeral III in the name iron(III) oxide indicates that: there are three iron atoms per formula unit. there are three oxygen atoms per formula unit. there are three times as many iron atoms present as oxygen atoms. iron is present in the form of +3 ions.

iron is present in the form of +3 ions.

The minimum combined kinetic energy reactant particles must possess in order for their collision to result in a reaction is called the..... dissociation energy collision energy activation energy orientation energy

activation energy

An element is a substance that..... cannot be broken down into simpler substances by chemical or physical means. can be broken down into simpler substances by chemical means. cannot be broken down into simpler substances by physical means. can be broken down into simpler substances by physical means.

cannot be broken down into simpler substances by chemical or physical means.

For which of the following types of mixtures do the particles scatter light? colloidal dispersion suspension true solution no correct answer

colloidal dispersion

Assign the following reaction to one of the reaction classifications given in the response list: 2NO2 + H2O2 →2HNO3 decomposition combination displacement exchange

combination

A substance has a high density. Choose the appropriate classification from the response list below: could be an element or a compound. can neither be an element nor a compound. You Answered could be an element but not a compound. could be a compound but not an element.

could be an element or a compound.

Which of the following general reaction types is characterized by there being a single reactant? combination decomposition displacement exchange

decomposition

For a collision between molecules to result in reaction, the molecules must possess a certain minimum energy and..... exchange electrons. interact with a catalyst for at least one second. have a favorable orientation relative to each other when they collide. more than one correct response. no correct response.

have a favorable orientation relative to each other when they collide.

Isotopes of a given element...... have the same mass number but different numbers of protons. have different mass numbers but identical numbers of protons. have the same atomic number but different chemical properties. have the same mass number but different chemical properties.

have different mass numbers but identical numbers of protons

Whether a reaction is exothermic or endothermic is determined by..... the activation energy. the physical state of the reactants. how reactant and product potential energies compare. whether a catalyst is present.

how reactant and product potential energies compare.

For which of the following types of ionic compounds are most examples insoluble in water? nitrates sulfates hydroxides chlorides

hydroxides

Crenation of red blood cells occurs when the cells are placed in a(n)..... hypotonic solution isotonic solution hypertonic solution physiological saline solution

hypertonic solution

For representative elements, valence electrons are those electrons located..... in s orbitals. closest to the nucleus. in the outermost subshell. in the outermost shell.

in the outermost shell.

When a substance undergoes a chemical change it is always true that...... it changes from a solid to a gas. it liquifies. the temperature of the substance increases. it is converted to a new kind of matter with a different composition.

it is converted to a new kind of matter with a different composition

Most reactions are carried out in liquid solution or in the gaseous phase because in such situations..... activation energies are higher. it is easier for reactants to come in contact with each other. kinetic energies of reactants are lower. products are less prone to decomposition when compared to the solid phase.

it is easier for reactants to come in contact with each other.

Which of the following statements correctly characterizes the subatomic particle called a neutron? its mass is about that same as that of a proton. it has a negative charge. it contributes 25% of the mass of an atom. Its mass is less than that of an electron.

its mass is about that same as that of a proton.

Formation of a positive ion is the result of an atom: gaining one or more protons. losing one or more protons. losing one or more electrons. gaining one or more electrons.

losing one or more electrons.

Which of the following pairings of compound name and compound formula is incorrect? more than one correct response sodium oxide - Na2O no correct response magnesium sulfide - MgS2 potassium chloride - KCl

magnesium sulfide - MgS2

Avogadro's number is equal to the number of..... atoms in one mole of N2 atoms in one-half mole of CO more than one correct response molecules in one mole of N2O4 no correct response