CHEM

A chemist has a block of aluminum metal (density is 2.7 g/mL). The block weighs 1.5 g. What is the volume, in mL, of the aluminum block?

0.56 mL

Provide the correct IUPAC name for Cl₂O₇.

Dichlorine heptoxide

Which of the following states of matter is pictured below?

gas

Italian dressing contains olive oil and vinegar, which will separate out from each other if left to sit. This makes the dressing a:

heterogeneous mixture

A mass spectrometer measures neon to have two masses: 20 and 22 atomic mass units. These are: A) Isotopes B) Ions C) Compounds D) None of the above

(A)

A strong electrolyte will A) completely dissociate in solution B) will only partially dissociate in aqueous solution. C) will not dissociate in solution. D) will be insoluble in solution.

(A)

Classify the compound, CaF₂ as a simple ionic compound, a polyatomic ionic compound, or a covalent compound. A) simple ionic compound B) polyatomic ionic compound C) covalent compound

(A)

Which of the following compounds contains a polyatomic ion? A) CO₂ B) MgCO₃ C) SiO₂ D) CO

(B)

A nonelectrolyte A) will conduct electricity when placed in aqueous solution. B) will only partially dissociate in aqueous solution. C) will not be dissolved in water. D) will not form any ions in aqueous solution.

(D)

Complete the following nuclear decay process: ²³⁵₉₂U → ⁴₂He + ___ A) ²³⁹₉₄Pu B) ²³¹₉₄Pu C) ²³¹₉₂U D) ²³¹₉₀Th E) ²³⁹₉₀Th +

(D)

Classify the compound, Na₂O, as a simple ionic compound, a polyatomic ionic compound, or a covalent compound. A) simple ionic compound B) polyatomic ionic compound C) covalent compound

(A)

The atomic mass of germanium (Ge) on the periodic table is 72.630 amu. Which of the following best explains why the atomic mass is a fraction between 72 and 73? A) The presence of different isotopes B) The presence of different isomers. C) The formation of different ions. D) The presence of different allotropes. E) The presence of different amounts of protons.

(A)

The compound NaBr is: A) Ionic B) Polar covalent C) Nonpolar covalent D) Metallic E) Not enough info

(A)

Which element is classified as a transition metal? A) lithium (Li) B) zirconium (Zr) C) tellurium (Te) D) xenon (Xe)

(B)

Which one of the following is a strong acid? A) HNO₂ B) HF C) HClO₄ D) HC₂H₃O₂

(C)

Which of the following is a step that is NOT in the scientific method? A) making observations B) formulating hypotheses C) modifying laws D) performing experiments

(C) Modifying laws

The equation below is best described as ___________. ¹⁹⁵₈₀Hg → ¹⁹⁵₇₉Au + ⁰₊₁e A) alpha decay. B) beta decay. C) gamma emission. D) positron emission.

(D)

What type of calorimeter would be appropriate for measuring heats of combustion? A) constant temperature calorimeter B) differential scanning calorimeter C) coffee cup calorimeter D) bomb calorimeter

(D)

Which of the following elements would be chemically similar to selenium (Se)? A) Br B) Sc C) As D) S E) Ca

(D)

Which of the following hypotheses is testable by using the scientific method? A) All men are mortal. B) The best color is blue. C) No life exists on other planets. D) All swans are white. E) Swimming is fun.

(D)

Which of the following is NOT a form of potential energy? A) chemical B) electrical C) gravitational D) thermal

(D)

Which of the following processes decreases the atomic number by two? A) gamma-ray production B) beta production C) positron-particle production D) alpha-particle production E) proton production

(D)

Which of the following statements is true? A) Osmotic pressure is the pressure from particles travelling through a membrane. B) Osmotic pressure is the pressure required to force solvent particles to pass through a membrane. C) Osmotic pressure is the pressure required to separate the solvent from the solute. D) Osmotic pressure is the pressure required to stop osmosis.

(D)

Which one of the following compounds in aqueous solution would be best described by the picture below? Hint: look at the ratio of red to blue species in solution

(D)

The following picture would be best described as A) a solid element B) a liquid mixture C) a liquid compound D) a solid mixture E) a liquid element

(D) A solid mixture

Which of the following are chemical properties of matter? A) mass B) volume C) density D) flammability

(D) Flammability

Which of the following is an extensive physical property of matter? A) Boiling point B) Reactivity C) Density D) Length E) Freezing point

(D) Length

An unknown solid is added to water in a calorimeter. The temperature of the water increases. What does this say about the reaction? A) The reaction is exothermic. B) The reaction is endothermic. C) The reaction has absorbed heat from the solution. D) The reaction has released heat to the solution. E) Both A and D.

(E)

Based on the positions of the following elements on the periodic table, which of them would you expect to form a 3+ cation? A) scandium B) aluminum C) phosphorus D) calcium E) Both A and B

(E)

What does the mass number of an atom represent? A) number of neutrons in the atom B) number of protons in the atom C) atomic mass of the element D) total number of electrons and neutrons in the atom E) total number of protons and neutrons in the atom

(E)

What is the balanced nuclear reaction for the following process? Iodine-131, used to treat hyperactive thyroid glands, decays by producing a β⁻ particle. A) ¹³¹₅₃I → ⁰₁e + ¹³¹₅₂Te B) ¹³¹ ⃰ ₅₃I → ⁰₀γ + ¹³¹₅₃I C) ¹³¹₅₃I → ⁴₂He + ¹²⁷₅₁Sb D) ¹³¹₅₃I → ¹₁H + ¹³⁰₅₂Te E) ¹³¹₅₃I → ⁰₋₁e + ¹³¹₅₄Xe

(E)

An unknown element X has the following isotopes: ¹⁰X (20.00% abundant, atomic mass = 10.01 amu) and ¹¹X (80.00% abundant, atomic mass = 10.99 amu). What is the average atomic mass in amu of X?

10.81 amu

Draw the Lewis structure of OF₂ and then determine the number of nonbonding electron pairs on the central atom.

2 electron pairs

A radioactive isotope of vanadium, ⁵³₂₃V, decays by producing a β⁻ particle and gamma rays. The nuclide formed has the atomic number

24

A chemist encounters an unknown solid. They drop the solid into a graduated cylinder containing water, and find the volume change is 3.20 mL. If the solid weighs 10.5 g, what is the density in g/mL of the metal?

3.28 g/mL

Predict the chemical formula for the ionic compound formed by Al³⁺ and C₂H₃O₂⁻

Al(C2H3O2)3

Predict the chemical formula for the ionic compound formed by the elements Al and I

Al1I3

Write the chemical formula for aluminum fluoride

AlF3

Provide the correct IUPAC name for Al(NO₂)₃?

Aluminum nitrite

Provide the correct IUPAC name for K₂O

Potassium oxide

Provide the correct IUPAC name for MgF₂.

Magnesium fluoride

Determine the number of valence electrons in (C₂Cl₂, or ClCCCl) and then draw the corresponding Lewis structure. A) 21 B) 22 C) 24 D) 20 E) 25

(B)

How many electrons are in a neutral ⁴¹Ca atom? A) 2 B) 20 C) 21 D) 41

(B)

How many neutrons are in an atom of uranium-235? A) 92 B) 143 C) 235 D) 238.0

(B)

The nucleus of an atom contains: A) Protons and electrons B) Protons and neutrons C) Electrons and neutrons D) Protons, neutrons and electrons E) Electrons only

(B)

What type of medical imaging involves radioactivity as the imaging source? A) MRI B) PET scans C) CT scans D) X-ray imaging E) Ultrasound imaging

(B)

Which has a greater mass? A) Electron B) Proton C) They have equal masses D) Not enough information

(B)

The predominant intermolecular force between molecules of I₂ is _____ A) ionic bonds. B) dipole-dipole interactions. C) ion-dipole interactions. D) dispersion forces. E) covalent bonds.

(D)

10 g of a radioactive substance was placed in an airtight container 50 years ago. When the container is opened, only 2.5 g remains. What is the half-life of this material? A) 5 years B) 25 years C) 50 years D) 80 years E) 100 years

(B)

What is the definition of a scientific law? A) It is witnessed and can be recorded. B) It gives an overall explanation of a natural phenomenon. C) It involves both a number and a unit. D) It summarizes an observable behavior.

(D)

A temperature of 103°F or higher is considered a medical emergency. Patient A comes in with a temperature of 38°C. Patient B comes in with a temperature of 313 K. Is either patient having a medical emergency? A) Yes, patient A only. B) Yes, patient B only. C) Yes, both patients. D) No, neither patient. E) Not enough information to determine

(B)

An atom of the isotope ¹³³Cs contains how many protons (p), neutrons (n), and electrons (e)? A) 55 p, 55 n, 55 e B) 55 p, 78 n, 55 e C) 133 p, 133 n, 133 e D) 55 p, 133 n, 55 e E) 133 p, 55 n, 55 e

(B)

Consider the reaction below. Which species are conjugate acid/base pairs? HSO₃⁻ (aq) + HCN (aq) ⇌ H₂SO₃ (aq) + CN⁻ (aq) A) HSO₃⁻, CN⁻ B) HSO₃⁻, H₂SO₃ C) H₂SO₃, CN⁻ D) HCN, H₂SO₃

(B)

What nuclide is formed when Th-230 undergoes alpha emission? A) Au-226 B) Pb-226 C) Ra-230 D) Ra-226 E) Pa-230

(D)

The conjugate acid of H₂PO₄⁻ is A) H₃PO₄ B) HPO₄²⁻ C) PO₄³⁻ D) H₂PO₄

(A)

The element antimony (Sb) has an atomic mass of 121.76 amu. Two naturally occurring isotopes of antimony are ¹²¹Sb (57% abundant) and ¹²³Sb (43% abundant). In a sample of 100 Sb atoms, what is the probability that a single selected atom has a mass of 121.76 amu? A) 0% B) 43% C) 57% D) 100% E) Not possible to determine.

(A)

The equation below is best described as ___________. ²¹⁰₈₄Po→ ⁴₂He + ²⁰⁶₈₂Pb A) alpha decay. B) beta decay. C) gamma emission. D) positron emission.

(A)

What intermolecular forces are present in both molecules of CH₃CH₂OH and CH₃CH₂NH₂? A) Dispersion forces, dipole-dipole forces, and hydrogen bonding. B) Dipole-dipole forces only. C) Dipole-dipole forces and hydrogen bonding. D) Dispersion forces and dipole-dipole forces

(A)

Which element is classified as a noble gas? A) helium (He) B) nitrogen (N) C) chlorine (Cl) D) francium (Fr)

(A)

Which of the following elements is NOT a metal? A) arsenic B) indium C) iridium D) lithium E) lutetium

(A)

Which of the following has the greatest amount of potential energy? A) a ball at the top of a hill. B) A ball rolling down a hill. C) A ball at the bottom of a hill. D) A ball thrown up and moving into the air.

(A)

Which of the following has the greatest mass? A) α particle B) neutron C) proton D) β⁻ particle E) neutrino

(A)

Which of the following is a chemical change? A) cooking an egg B) mixing oil and water C) tearing a piece of paper D) watching a DVD

(A)

Which of the following is an example of a colloid? A) milk B) coffee C) soda D) saltwater

(A)

Which of the following is an example of an ionic bond? A) K - F B) C - H C) Kr - H D) C - F

(A)

Which of the following options should be classified as a molecular compound? I. H₂S II. Br₂ III. CaO A) I only B) II only C) I and II only D) II and III only E) I, II and III

(A)

Which of the following represents an exact quantity? A) There are 2.54 cm in an inch. B) A man is 5 feet 10 inches tall. C) A man weighs 200 lb. D) It takes 15 minutes to drive to the grocery store. E) There are 80 grams of sugar in a serving of soda.

(A)

Which of the following would become more soluble in water at lower temperature? A) O₂ (g) B) CH₃CH₂CH₂CH₂CH₃ (l) C) C₆H₆ (l) D) C₆H₁₂O₆ (s)

(A)

Which of the following would you expect to have the lowest boiling point? A) H₂ B) F₂ C) HF D) H₂S

(A)

You were given a dose of 500 mg rather than 500 μg of a drug. How much of the drug did you receive? A) 1000 times more B) 100 times more C) 1000 times less D) 100 times less

(A)

Which of the following is an intensive physical property of matter? A) Specific heat capacity B) Flammability C) Mass D) Volume E) Reactivity

(A) Specific heat capacity

Which of the following best describes what takes place during the solvation process? A) Molecules of the solute are attracted to one another more than the solvent. B) Solvent molecules surround solute molecules and pull them out into the solution. C) Molecules of the solvent are attracted to one another and exclude solute molecules. D) Solvent and solute molecules arrange themselves along a boundary.

(B)

Which of the following elements would be chemically similar to calcium (Ca)? A) K B) Sr C) Sc D) S E) Ga

(B)

Which of the following is a physical change? A) rusting of a nail B) tearing a piece of paper C) cooking an egg D) burning wood

(B)

Which of the following represents an example of kinetic energy? A) a ball at the top of a hill. B) A ball rolling down a hill. C) A ball at the bottom of a hill.

(B)

Which of the following statements is true about the solubility of CO₂ (g) in H₂O (l)? A) CO₂ is not soluble in H₂O. B) CO₂ will be more soluble at lower temperatures. C) The solubility of CO₂ is independent of the temperature. D) CO₂ will be more soluble at lower pressures.

(B)

Which of the following statements regarding a gamma ray is true? A) It is less penetrating than a beta ray. B) It is not deflected by an electric field. C) It is composed of neutrons. D) It is less penetrating than an alpha ray. E) None of these statements are true.

(B)

Which of the following would become more soluble in water at higher pressure? A) NaOH (s) B) N₂ (g) C) C₆H₆ (l) D) C₆H₁₂O₆ (s)

(B)

Which one of the following is a strong base? A) Mg(OH)₂ B) Ca(OH)₂ C) NH₃ D) CH₃OH

(B)

Which one of the following is the correct dissociation equation for Li₂CO₃? A) Li⁺(aq) + CO₃²⁻ (aq) → Li₂CO₃ (s) B) Li₂CO₃ (s) → 2 Li⁺(aq) + CO₃²⁻ (aq) C) Li₂CO₃ (s) → Li⁺(aq) + CO₃²⁻ (aq) D) Li₂CO₃ (s) → Li⁺(aq) + C⁴⁻ (aq) + 3 O²⁻ (aq)

(B)

Which one of the following is an example of a compound? A) air B) water C) steel D) iron

(B) Water

Ammonia and hydrogen fluoride both have unusually high boiling points due to _____ A) dispersion forces. B) dipole-dipole interactions. C) hydrogen bonding. D) ion-dipole interactions. E) low molar masses.

(C)

Carbon dioxide is a _____ compound composed two types of _____ atoms. A) molecular; metal B) ionic; metalloid C) molecular; nonmetal D) ionic; metal

(C)

Determine the number of protons (p) and electrons (e) in Mg²⁺. A) 10 p, 12 e B) 12 p, 12 e C) 12 p, 10 e D) 12 p, 14 e E) 10 p, 10 e

(C)

In a covalent bond A) two atoms exchange electrons and the ions are attracted to one another. B) two ions come together and form a crystal lattice. C) two atoms share valence electrons and those shared electrons form the chemical bond. D) two elements react and form a new compound.

(C)

Neutral atoms of all isotopes of a given element have the same A) number of protons and neutrons B) number of neutrons C) number of electrons D) mass numbers E) masses

(C)

The net charge on an atom of a given element changes as ______ are added or removed. A) neutrons B) protons C) electrons D) protons and electrons

(C)

What is ionizing radiation? A) Radiation that exists as a plasma. B) Radiation required to initiate a fission reaction. C) Radiation that can cause ionization processes to occur. D) Radiation that occurs as charged ions. E) Radiation that is required to initiate a fusion reaction.

(C)

What is the product of alpha emission from uranium-238? A) ²³⁴U B) ²³²Th C) ²³⁴Th D) ²³⁷Np E) ²³¹Pa

(C)

Which of the following compounds contains a polyatomic ion? A) NaCl B) Na₂S C) NaOH D) Na₃N

(C)

Which of the following is NOT an alkali or alkaline earth element? A) Ra B) Cs C) Sc D) Be E) Rb

(C)

Which of the following is an example of an ionic bond? A) F - F B) O - F C) Na - O D) Na - Na

(C)

Which of the following statements about subatomic particles are false? I. Neutrons reside inside of the nucleus. II. The atomic number is equal to the number of neutrons in the nucleus of an atom. III. Electrons are more massive than protons. A) I and II only B) I and III only C) II and III only D) I, II and III

(C)

Which of the following statements is true? A) A buffer forms when any acid or base are mixed together. B) A buffer forms when a strong acid is mixed with a weak acid. C) A buffer forms when a conjugate weak acid/weak base pair are mixed together. D) A buffer forms when a weak acid is mixed with a weak base.

(C)

Which one of the following is the correct dissociation equation for AlBr₃? A) AlBr₃ (s) → 3 Al⁺(aq) + Br⁻ (aq) B) 2 AlBr₃ (s) → 2 Al³⁺(aq) + 3 Br₂⁻ (aq) C) AlBr₃ (s) → Al³⁺(aq) + 3 Br⁻ (aq) D) AlBr₃ (s) → Al⁺(aq) + 3 Br⁻ (aq)

(C)

Which subatomic particle is found in the nucleus and has a positive charge? A) Electron B) Neutron C) Proton D) Positron

(C)

Which of the following are physical properties of matter? A) stability B) reactivity C) density D) flammability

(C) Density

If you go mini-golfing, in which of these scenarios are you precise but not accurate? A) You hit all holes in one. B) You take six strokes at each hole. C) It always takes you a long time to get your shots in D) All of your shots are off, but they all go to the same place.

(D)

The nucleus of an atom contains: A) Protons and electrons B) Protons and neutrons C) Electrons and neutrons D) Protons, neutrons and electrons E) Electrons only

(D)

The oxygen molecule, O₂: A) Has no charge (neutral) B) Is diatomic C) Is homonuclear D) All of the above

(D)

The pH of a basic solution is 9.77. What is [OH⁻]?

6x10^-5 M

Americium-241 is widely used in smoke detectors. Calculate the amount of americium-241 consumed in a smoke detector (initially containing 5.00 µg of Am), in micrograms, that has been used for one year if the half-life is 433 years.

8.00 × 10⁻³ µg

One of the radioactive isotopes used in medical treatment or analysis is chromium-51. The half-life of chromium-51 is 28 days. How many days is/are required for the activity of a sample of chromium-51 to fall to 12.5 percent of its original value?

84 days

The accepted value for the density of iron is 7.9 g/mL. Which of the following sets of experimental data for the density of iron is the most accurate? A) Group 1: 7.98 g/mL, 7.85 g/mL B) Group 2: 7.65 g/mL, 7.64 g/mL C) Group 3: 7.03 g/mL, 8.54 g/mL D) Group 4: 5.43 g/mL, 5.47 g/mL

A

Write the chemical formula for the hydronium ion

H3O+

Provide the correct IUPAC name for IF₅.

Iodine pentafluoride

Which of the following states of matter is portrayed by the following description: assumes the shape of its container because it has a definite volume but no specific shape?

liquid