Chemistry exam part 2

Which of the following statements is associated with the quantum theory of atomic structure?

Each electron has a defined amount of energy that can be defined by a set of numbers.

Which statement is NOT a feature of John Dalton's four-part model of the atom? Atoms of the same element are exactly alike. All matter is made of atoms that can be combined. Electrons orbit the nucleus of the atom in electron clouds. Atoms of two or more elements can be combined to form new substances

Electrons orbit the nucleus of the atom in electron clouds.

Calculate the mole fractions of each compound in 19.4 g of H2SO4 in 0.251 L of H2O (density of water is 1.00 g/mL). H2SO4: 0.315, H2O: 0.685 H2SO4: 0.274, H2O: 0.726 H2SO4: 0.191, H2O: 0.809 None of the listed answers are correct H2SO4: 0.0143, H2O: 0.986

H2SO4: 0.0143, H2O: 0.986

Which of the following is an Arrhenius acid?

HBr

Which of the following Brønsted-Lowry acids is likely the strongest?

HI

Identify the species being oxidized and reduced in this reaction: 3 Hg2+ + 2 Fe (s) 3 Hg2 + 2 Fe3+ Hg2+: oxidized, Fe: reduced Hg2: oxidized, Fe3+: reduced Hg2+: reduced, Fe: oxidized Hg2: reduced, Fe3+: oxidized None of the listed answers are correct

Hg2+: reduced, Fe: oxidized

If a gas occupies a volume of 0.75 L at 130 kPa pressure, what pressure would the gas exert if it were placed in a 4.0-L container at the same temperature? 690 kPa 240 kPa 410 kPa 24 kPa None of the listed answers are correct

24 kPa

One atom of iron contains 26 protons, 30 neutrons, and 26 electrons. Which of the following would be possible for another atom of iron? 27 protons, 30 neutrons, 26 electrons None of the listed answers are correct 26 protons, 28 neutrons, 26 electrons 25 protons, 30 neutrons, 26 electrons 25 protons, 30 neutrons, 27 electrons

26 protons, 28 neutrons, 26 electrons

What volume of 3 N base is required to neutralize 80 mL of 1 N acid?

27ml

The reversible reaction:2SO2(g) + O2(g) ⇄ 2SO3(g)has come to equilibrium in a vessel of specific volume at a given temperature. Before the reaction began, the concentrations of the reactants were 0.060 mol/L of SO2 and 0.050 mol/L of O2. After equilibrium is reached, the concentration of SO3 is 0.040 mol/L. What is the equilibrium concentration of O2?

0.030 M

Kc = 0.040 for the system below at 450oC. If a reaction is initiated with 0.40 mole of Cl2 and 0.40 mole of PCl3 in a 2.0 liter container, what is the equilibrium concentration of Cl2 in the same system?PCl5(g) ⇄ PCl3(g) + Cl2(g)

0.07 M

A calorimeter holds 125 g water at 22.0°C. A 45 g sample of silver at 130.0°C is added to the water, and the final temperature of the water and silver is 24.2°C. The specific heat of water is 4.18 J/g°C. What is the specific heat of silver?

0.241 J/g°C

If a gas occupies a volume of 0.25 L at -2.3°C, by what amount would the volume increase if the gas were heated to 82°C at constant pressure? 0.08 L 0.33 L 0.06 L None of the listed answers are correct 0.19 L

0.33 L

The temperature of a 55 gram sample of a certain metal drops by 113 °C as it loses 3500 Joules of heat. What is the specific heat of the metal? 0.72 J/g x °C 0.48 J/g x °C None of the listed answers are correct 0.56 J/g x °C 0.39 J/g x °C

0.56 J/g x °C

Calculate the molarity of 12.4 g KCl in 289.2 mL solution.

0.576 M KCl

4,786 Joules of heat are transferred to a 89.0 gram sample of an unknown material, with an initial temperature of 23.0 °C. What is the specific heat of the material if the final temperature is 89.5 °C? None of the listed answers are correct 0.629 J/g x °C 0.585 J/g x °C 0.763 J/g x °C 0.809 J/g x °C

0.809 J/g x °C

How many atoms of sulfur are represented by the formula H2SO4?

1

Which of the following equations represents the decomposition of a chemical compound via an electrolytic reaction? O2 + 2H2 → 2H2O E° = 2.06 V Ni + Cu2+ → Ni2+ + Cu E° = +0.57 V 2H2O → O2 + 2H2 E° = −2.06 V Fe + 2Ag+ → Fe2+ + 2Ag E° = +1.24 V None of the listed answers are correct

2H2O → O2 + 2H2 E° = −2.06 V

What is the balanced chemical equation for the reaction of potassium with sulfur?

2K + S → K2S

A 10.50 gram sample of a compound is decomposed to yield 3.40 g Na, 2.37 g S, and 4.73 g O. What is the mass percentage of each element in this compound?

32.4% Na, 22.6% S, 45.1% O

How many pairs of electrons are shared in a double bond?

4

In what orbital would the two valence electrons of strontium be found? 5p None of the listed answers are correct 4s 5s 4p

5s

Calculate the molality of 1.80 mol KCl in 16.0 mol of H2O . None of the listed answers are correct 5.32 molal KCl 4.73 molal KCl 7.41 molal KCl 6.25 molal KCl

6.25 molal KCl

Write the balanced half reactions of the following reaction: H+ + 2 H2O + 2 MnO4- + 5 SO2 → 2 Mn2+ + 5 HSO4- in acidic solution

8 H+ + MnO4- + 5 e- → Mn2+ + 4 H2OSO2 + 2 H2O → HSO4- + 3 H+ + 2 e-

Find the mass of a sample of water if its temperature dropped 24.8 °C when it lost 870 J of heat.

8.38 grams

An atom of uranium, whose atomic number is 92, transforms in nature to an atom of thorium plus a nucleus of helium, whose atomic number is 2. What is the atomic number of thorium?

90

Which pressure measurement describes the lowest gas pressure?

95,000 Pa

Calculate the molarity of 48.0 mL of 6.00 M H2SO4 diluted to 0.250 L .

1.15 M H2SO4

A closed flask contains a mixture of three gases: argon, oxygen, and helium. The pressure in the flask is measured to be 640 mmHg. If the partial pressures of argon and oxygen are equal and the partial pressure of helium is half the partial pressure of argon, what is the partial pressure of helium? None of the listed answers are correct 512 mmHg 256 mmHg 213 mmHg 128 mmHg

128 mmHg

How many joules of heat are required to raise the temperature of 550 g of water from 12.0 °C to 18.0 °C?

13807.2 J = 1.38 x 104 J

A burner on an electric range has a heat capacity of 345J/K. What is the value of q, in kilojoules, as the burner cools from a temperature of 467°C to a room temperature of 23°C?Hint: q = C∆T

153kJ

8750 J of heat are applied to a piece of aluminum, causing a 56.0 °C increase in its temperature. The specific heat of aluminum is 0.9025 J/g x °C. What is the mass of the aluminum? 318 grams None of the listed answers are correct 256 grams 447 grams 173 grams

173 grams

An aluminum atom possesses three valence electrons. Which is most likely to occur for an aluminum atom to obtain a complete valence shell?

2

What is the net charge on two alpha particles and two beta particles?

2

Write a balanced equation for the following reaction: O2 + Sb → H2O2 + SbO2- in basic solution

2 OH- + 2 Sb + 3 O2 + 2 H2O → 2 SbO2- + 3 H2O2

Determine the standard reduction potential for the metal Mg from the following information.

2.37 V

Consider the reaction A + 2B → C. The rate law for this reaction is second order in A and second order in B. If the rate constant at 25 °C is 1.25 x 10-2 s-1 , find the rate of reaction when the concentration of A is 0.27M and the concentration of B is 0.32 M. Rate = 3.1 x 10-4 M/s Rate = 1.8 x 10-6 M/s Rate = 1.7 x 10-7 M/s Rate = 9.3 x 10-5 M/s None of the listed answers are correct

Rate = 9.3 x 10-5 M/s

The reaction C6H5N2Cl (aq) + H2O (l) → C6H5OH (aq) + N2 (g) + HCl (aq) is first order in C6H5N2Cl and zero order in H2O. What is the rate expression?

Rate = k[C6H5N2Cl]

A chemist wants to reduce the pollutants emitted by gasoline as it burns in engines. To achieve this goal, the chemist decides to add a substance to gasoline. Which pair of criteria should govern the chemist's choice of an additive?

The additive should burn in air and dissolve in gasoline.

A student is making a diagram to illustrate the hydrogen atom according to the Bohr model. She wants to show how the model correlates to the hydrogen emission spectrum. Which of the following should be true about the diagram drawn by the student if the diagram is to be accurate?

The diagram should show several energy levels with arrows pointing in the direction from the lower to the higher levels to show the movement of hydrogen's one electron in creating the emission lines.

What is the best description of the release of energy during a chemical reaction?

The energy is released as chemical bonds form.

A student stirs the elements copper and sulfur together and then heats them in a test tube. After heating, the material in the tube does not have the chemical or physical properties of either copper or sulfur. The material in the test tube is most likely

a compound made of copper and sulfur chemically bonded to each other

Which of the following items would dissolve most quickly in a glass of warm water? sugar cane None of the listed answers are correct a spoonful of granulated sugar rock candy a sugar cube

a spoonful of granulated sugar

The Bohr model of the atom proposed that _____.

electrons have a fixed amount of energy

Which valence electrons in tin are responsible for determining how it interacts with other elements?

electrons in the 5s and 5p orbitals

An element that tends to give up its valence electrons during a chemical reaction is _____. electronegative a noble gas a nonmetal electropositive None of the listed answers are correct

electropositive

Which of the following is least likely to be a benefit of introducing radioactive substances into the body in a medical procedure? ability to trace internal activities in the body None of the listed answers are correct finding amino acids in protein tracing the pathway of blood circulation locating cancerous tumors

finding amino acids in protein

Which reaction would result in a change in odor, indicating a chemical change has occurred?

frying an egg

Which of the following food items is likely the most acidic?

grapefruit

Which of the following determines the identity of an element? the shape of its nucleus None of the listed answers are correct its atomic number the mass of its nucleus its atomic mass number

its atomic number

Which of the following diagrams is the correct Lewis dot structure for a molecule of acetic acid, H3CCOOH?

its the picture with 2 dots on each side of the O vertically and another one horizontally so 4 per O

Which element has the atomic symbol Pb?

lead

The neutral particles found in the nucleus of an atom are referred to as _____.

neutrons

What type of compound is composed of covalently bonded atoms and has a high melting point?

none

The electrons of an atom are located in _____.

orbitals outside the nucleus

A chemist is doing research to find a better way to process natural gas after it is removed from the ground. Which branch of chemistry best describes this chemist's work? None of the listed answers are correct biochemistry organic chemistry nuclear chemistry electrochemistry

organic chemistry

Which of the following gives a general description of most carbohydrates?

organic compounds consisting of carbon, hydrogen, and oxygen, with a hydrogen:oxygen ratio of 2:1

What experimental work led Dalton to his atomic theory?

partial pressure gas laws

Which of the following would most likely result in an increase in reaction rate?

placing the reactants on a hotplate

Typically, if the valence orbital of an atom is full, the atom is _____. relatively stable None of the listed answers are correct unstable somewhat unstable an ion

relatively stable

Which of the following changes will increase the total amount of of Cl2 that can be produced?

removing the Cl2 as it is formed

A solution that has dissolved as much of the solute as it can at a specific temperature is said to be _____.

saturated

What is the overall order of reaction for Rate = k[NO2]2 ?

second order

When boron reacts with another element, it typically _____ its valence electrons.

shares

Which of the following can be represented by a single chemical symbol?

sodium

Which of the following references are best to use when predicting whether a double-displacement reaction will occur? solubility rules and oxidation numbers activity series and oxidation numbers activity series and a periodic table solubility rules and a periodic table None of the listed answers are correct

solubility rules and a periodic table

Which of the following diagrams is the correct Lewis dot structure for a molecule of acetic acid, H3CCOOH?

solve

What types of hybrid orbitals are used by the carbon atom in the covalently bonded molecule Cl2CO? None of the listed answers are correct sp2 orbitals sp3 orbitals sp orbitals s and p orbitals

sp2 orbitals

A scientific artist is assigned the task of drawing an illustration depicting particles of a solid. Which of the following best describes the drawing the illustrator should make?

spheres closely packed in a regular geometric pattern and vibrating in place

A physical chemist is working on a project for an environmental engineering firm. In which project might this chemist likely participate? studying the effect of acid rain on plant life studying fossils found in the area for evidence of disease studying the occurrence of trace minerals in organisms studying the bonding patterns of gases in the air

studying the bonding patterns of gases in the air

What did the gold foil experiment demonstrate? the density of mass in the nucleus None of the listed answers are correct the presence of electrons in the nucleus the presence of electrons around a nucleus the presence of protons in the nucleus

the density of mass in the nucleus

Most of the atom's mass can be found in _____. electrons None of the listed answers are correct quarks the nucleus orbitals outside the nucleus

the nucleus

What is inorganic chemistry? the study of how the principles of physics apply to chemical systems the study of chemical processes in living organisms the study of compounds that do not contain carbon as the primary element the study of carbon-based compounds and their derivatives None of the listed answers are correct

the study of compounds that do not contain carbon as the primary element

What is the overall order of reaction for Rate = k[NO]2[O2] None of the listed answers are correct third order second order 3/2 order zero order

third order

How many valence electrons does the element boron have?

three

An oxygen atom with an oxidation number of +2 has _____.

two fewer electrons than the neutral atom

A chemical bond forms when the _____ of one element interact(s) with another element. neutrons valence protons None of the listed answers are correct nucleus valence electrons

valence electrons

You make a solution of salt, water, sugar, and instant coffee. Which of these is the solvent? sugar None of the listed answers are correct salt instant coffee water

water

Which of the following is a true statement about the nucleus of an atom? It is very small compared with the size of the atom. None of the listed statements are true. It moves quickly in the atom. It makes up only a small fraction of the atom's weight. It is negatively charged.

It is very small compared with the size of the atom.

An ion of oxygen contains eight protons and has a charge of 2-. What must occur for this ion to become a neutral oxygen atom? It must gain two electrons. It must lose two protons. It must gain two protons. It must lose two electrons. None of the listed answers are correct

It must lose two electrons.

In the photoelectric effect, light of a certain frequency causes ejection of an electron from a substance. If a different frequency of light is used, the photoelectric effect is not observed even when the light intensity is increased. Which of the following statements about light is fundamental to the explanation for these observations? None of the listed answers are correct Light can be described in terms of wavelength and frequency. Light can be described as having a constant speed. Light can be described as electromagnetic waves. Light can be described as a stream of photons, which are particles of light.

Light can be described as a stream of photons, which are particles of light.

Magnesium-24 and magnesium-31 are two isotopes of magnesium (atomic number 12). Which statement best describes the relative stability of these nuclides?

Magnesium-31 is less stable and is more likely to undergo radioactive decay.

The following equation shows the net reaction taking place in a voltaic cell. Which of the following are the balanced half-reactions representing changes occurring in this cell? Mn + Br2 → Mn2+ + 2Br− E°= +2.27 V

Mn → Mn2+ + 2e− Br2 + 2e− → 2Br−

Express the following information as a chemical equation. At 25°C and at a constant pressure, dinitrogen trioxide gas decomposes to nitrogen monoxide and nitrogen dioxide gases with the absorption of 0.533kJ of heat for every gram of dinitrogen trioxide that decomposes.

N2O3(g) → NO(g) + NO2(g) ΔH = +40.5kJ

Determine the oxidation number of the element in this compound: N2 N: 1 N: -2 N: 0 None of the listed answers are correct N: 2

N: 0

Which of the following equations represents a synthesis reaction?

Na2O + H2O → 2NaOH

A student discovered two NaCl solutions that each contained evidence of NaCl solid. He removed exactly 10.0 mL of liquid from each and weighed the samples. Sample A had a mass of 11.998 g, while sample B had a mass of 12.202 g. What explains the difference?

None of the listed answers are correct

How many grams of copper can be heated from 22.5°C to 35.0°C by the same quantity of heat that can raise the temperature of 145g of H2O from 22.5°C to 35.0°C?

None of the listed answers are correct

What is the atomic symbol for tin? None of the listed answers are correct Nt Ti Tn St

None of the listed answers are correct

When using the combined gas law, what value must remain constant? temperature volume pressure None of the listed answers are correct amount of gas

None of the listed answers are correct

A student wants to develop a way to contain a plasma. The student thinks that she can take advantage of one of the properties of a plasma to contain it in a magnetic field. Which property might that be?

Plasmas consist of charged particles.

Consider the reaction 2A + B → C + 2 D. The rate law for this reaction is first order in A and first order in B. If the rate constant at 25 °C is 3.01 x 102 s-1 , find the rate of reaction when the concentration of A is 0.47 M and the concentration of B is 0.79 M. Rate = 130 M/s Rate = 90 M/s Rate = 110 M/s None of the listed answers are correct Rate = 150 M/s

Rate = 110 M/s

Which of the following characters is a possible azimuthal quantum number?

0 1

Identify the oxidizing agent in the following reaction:Cr2O3(s) + Al(s) → Cr(s) + Al2O3(s)

Cr2O3(s)

A lithium atom possesses 2 electrons in its inner electron shell and 1 electron in its outermost shell. What is the charge on a lithium ion?

+1

The specific heat of iron is 0.4494 J/g x °C. How much heat is transferred when a 4.7 kg piece of iron is cooled from 180 °C to 13 °C? Remember you must use the same units so you will have to convert your mass to grams before you begin. -442497.42 J = -4.4 x 105 J -581887.82 J = -5.8 x 105 J None of the listed answers are correct -273897.37 J = -2.7 x 105 J -352734.06 J = -3.5 x 105 J

-352734.06 J = -3.5 x 105 J

Which statement best describes the initiation of a nuclear chain reaction?

A neutron released in the nuclear reactor causes a uranium nucleus in a fuel rod to split.

Which of the following statements provides information about the azimuthal quantum number of an electron?

An electron is in a p orbital in an atom.

How does an exothermic reaction compare with an endothermic reaction?

An endothermic reaction absorbs energy, and an exothermic reaction releases energy.

A chemist pours two chemicals in a beaker and observes their reaction. The chemist then notices that the beaker feels slightly cooler than it did before the reaction. What can the chemist conclude about the reaction? It is exothermic and not spontaneous. None of the listed answers are correct It is endothermic and spontaneous. It is exothermic and spontaneous. It is endothermic and not spontaneous. -wrong

ANSWER UNKNOWN

A student has been assigned to develop an argument that the emission spectrum of hydrogen illustrates the particle nature of light. Which of the following statements could she use in her argument? The particle nature of light is represented in the intensity of the emitted light. The particle nature of light is represented in the discrete energies associated with discrete emission lines. The particle nature of light is represented in the color of the emitted light. None of the listed answers are correct The particle nature of light is represented in the wavelength and frequency characteristics of the emitted light. -wrong

ANSWER UNKNOWN

If Earth has an oxidizing environment, what would you expect to happen to Mg(s) if left to sit over time? MgH2 would form. MgO2 would form. -wrong MgO would form. nothing None of the listed answers are correct

ANSWER UNKNOWN

What is the concentration of an acid that has 5.2 moles of HCl in 750 mL of water? 6.9 M None of the listed answers are correct 5.2 M -wrong 7.5 M 6.8 M

ANSWER UNKNOWN

Which item would react most rapidly if touched by a match? sawdust tree branches None of the listed answers are correct a log small twigs

ANSWER UNKNOWN BUT MAYBE SAWDUST

An atom of calcium becomes a cation when it forms an ionic bond with two atoms of chlorine. What is the charge on the calcium ion? 1+ 3+ 4+ None of the listed answers are correct -wrong 2+

ANSWER UNKNOWN maybe 2+

The conventional equilibrium constant expression (Kc) for the system below is:2ICl(s) ⇄ I2(s) + Cl2(g)

Cl2]

Write the balanced half reactions of the following reaction: CO2 + 2 NH2OH → CO + N2 + 3 H2O in basic solution 2 CO2 + 2 H2O + e- → 2 CO + 2 OH- OH- + 2 NH2OH → N2 + e- + 2 H2O 2 CO2 + H2O + 4 e- → CO + OH- 4 OH- + NH2OH → N2 + 4 e- + 4 H2O None of the listed answers are correct CO2 + H2O + 2 e- → CO + 2 OH- 2 OH- + 2 NH2OH → N2 + 2 e- + 4 H2O 2 CO2 + H2O + e- → 2 CO + 2 OH- OH- + 2 NH2OH → 2 N2 + 2 e- + 4 H2O

CO2 + H2O + 2 e- → CO + 2 OH- 2 OH- + 2 NH2OH → N2 + 2 e- + 4 H2O

Calculate the mole fractions of each compound in 233 g of CO2 in 0.409 L of water (density of water is 1.00 g/mL) .

CO2: 0.189, H2O: 0.811

A chemist is assigned the task of preparing gold for the manufacture of jewelry. The chemist knows that pure gold is too soft for use in jewelry. She decides to mix the gold with some silver. When she analyzes the metal mixture, she finds that the gold content is the same in all parts of the mixture. Which of the following has the chemist produced?

an alloy of gold and silver

Which branch of chemistry would be most relevant to a nutritionist? None of the listed answers are correct nuclear chemistry biochemistry inorganic chemistry physical chemistry

biochemistry

Which of the following is a physical property?

boiling point

What is the word equation that represents the decomposition of calcium nitrate into calcium nitrite and oxygen? calcium nitrate → calcium + nitrite + oxygen None of the listed answers are correct calcium nitrate → calcium nitrite + oxygen calcium + nitrate → calcium + nitrate + oxygen calcium nitrite + oxygen → calcium nitrate

calcium nitrate → calcium nitrite + oxygen

Which of the following gases will have the slowest rate of effusion? hydrogen gas (M = 2.0 g/mol) oxygen gas (M = 32 g/mol) water vapor (M = 18 g/mol) carbon dioxide (M = 44 g/mol)

carbon dioxide (M = 44 g/mol)

The change in matter in which chemical bonds are broken, rearranged, and reformed is called a _____.

chemical reaction

What type of compound is composed of covalently bonded atoms and has a high melting point? simple solid compound simple molecular compound complex solid compound None of the listed answers are correct complex molecular compound

complex solid compound

The transition metals contain valence electrons in an inner _____ orbital, that can contain up to ten electrons.

d