Eval Exam 1 Flashcards by Kimberly Roque

How many significant figures are in the value of the universal gas constant R = 0.0821 L•atm/mol-K?
A. 3
B. 4
C. 5
D. Infinite

D. Infinite

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How many significant figures should be reported in the final answer to the calculation 12.501 × 3.52 + 6.044?
A. 2
B. 3
C. 4
D. 5

A. 2

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A scientist records a temperature of 95°F. What is this temperature in Kelvin?
A. 273.15 K
B. 308.15 K
C. 335.15 K
D. 368.15 K

B. 308.15 K

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Which of the following pairs consists of intensive properties?
A. Heat capacity
B. Cell potential, free energy
C. Density, volume
D. Molarity, viscosity

D. Molarity, viscosity

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Which of the following is not a compound?
A. Marble
B. Quicklime
C. Ozone
D. Common salt

C. Ozone

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Which of the following statements is not correct?
A. Atoms are made of electrons, protons, and neutrons
B. All atoms of a given element contain the same number of neutrons
C. The atomic number of an element indicates the number of protons in its nucleus
D. Chemical combinations of atoms are called compounds

B. All atoms of a given element contain the same number of neutrons.

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Brass is an alloy of:
A. Al and Cu
B. Pb and Sn
C. Cu and Zn
D. Cu and Sn

C. Cu and Zn

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Which of the following is not a chemical change?
A. Burning of magnesium
B. Electrolysis of water
C. Rusting of iron
D. Dissolving salt in water

D. Dissolving salt in water

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A cylinder containing a gas is compressed to half its original volume. What will happen to its pressure at constant temperature?
A. Doubled
B. Halved
C. No effect
D. Cannot be determined

A. doubled

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A 0.239 g sample of an unknown gas is placed in a 100.0 mL flask at a temperature of 14°C and a pressure of 600 mmHg. What is the identity of the gas?
A. Chlorine
B. Nitrogen
C. Krypton
D. Xenon

A. Chlorine

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What is the density of propane (CH₃) at 25°C and 740 mm Hg?
A. 0.509g/L
B. 0.570g/L
C. 1.75g/L
D. 1.96g/L

C. 1.75g/L

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Which element is the major component in solar cells?
A. As
B. Ge
C. P
D. Si

D. Si

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Which family of elements has solid, liquid and gaseous members at 25°C and 1 atm?
A. Alkali metals (Li to Cs)
B. Pnictogens (N to Bi)
C. Chalcogens (O to Te)
D. Halogens (F to I)

D. Halogens (F to I)

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What is the correct formula for ammonium hydrogen phosphate?
A. (NH4)3PO4
B. (NH4)2HPO4
C. NH4H2PO4
D. (NH4)4P2O7

B. (NH4)2HPO4

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Which of the following species does not have the electron configuration: 1s² 2s² 2p⁶ 3s²?
A. K+
B. Cl-
C. S2-
D. Kr

D. Kr

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Which of the following elements has a greater electron affinity than oxygen?
A. Sulfur
B. Carbon
C. Neon
D. Fluorine

D. Fluorine

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What general trend is observed as you move from left to right across a period in the periodic table?
A. Atomic radius increases
B. Atomic radius decreases
C. Ionization energy decreases
D. Electronegativity decreases

B. Atomic radius decreases

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As one moves from the top to the bottom of a group in the periodic table, which of the following trends is observed?
A. The trend in atomic size cannot be predicted
B. Electronegativity decreases
C. Inonization energy increases
D. Atomic radius decreases

B. Electronegativity decreases

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Which statement correctly describes the radii of atoms and their corresponding ions?
A. Cations and anions are both larger than their neutral atoms
B. Cations are smaller than their atoms; anions are larger than their atoms
C. Cations are larger than their atoms; anions are smaller than their atoms
D. Cations and anions are both smaller than their neutral atoms

B. Cations are smaller than their atoms; anions are larger than their atoms

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What is the process of breaking down a large nucleus into smaller nuclei called?
A. Nuclear fission
B. Beta particle emission
C. Nuclear fusion
D. Gamma ray emission

C. Nuclear fission

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Which statement correctly describes how temperature generally affects the solubility of a solid solute in water?
A. Solubility decreases as temperature increases
B. Solubility increases as temperature increases
C. Temperature has no effect on solubility
D. Solubility is always highest at 0C

B. Solubility increases as temperature increases

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How does increasing temperature affect the viscosity of a liquid?
A. The molecules move more slowly, increasing viscosity
B. Intermolecular forces become stronger, increasing viscosity
C. Molecules move freely, decreasing viscosity
D. The liquid becomes more dense, increasing velocity

C. Molecules move more freely, decreasing viscosity.

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How many grams of potassium dichromate (K2C207, 294.2 g/mol) are required to prepare 250 mL of a 0.10 M solution?
A. 1.18g
B. 7.36g
C. 6.38g
D. 2.94g

B. 7.36g

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What is the molar concentration of the final solution after diluting 0.8214 g of KMnO4 in a series of dilutions?
A. 0.19 M
B. 2.08x10-5
C. 8.32x10-7 M
D. None of the above

C. 8.32x10-7 M

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Under the Bronsted-Lowry concept of acids and bases, a base is a(an): A. Proton donor B. Proton acceptor C. Electron paid donor D. Electron pair acceptor

B. Proton acceptor

Which of the following statements about pH is not true? A. It is the negative logarithm of the hydrogen ion concentration in a solution B. It is a measure of the acidity or alkalinity of a solution C. It is a measure of the amount of hydrogen ions in solution D. It remains constant regardless of changes in temperature

D. It remains constant regardless of changes in temperature.

When ammonium chloride undergoes ionization, the resulting solution will have a pH: A. <7 B. 7 C. >7 D. 14

A. <7

In which of the following titrations does pH = 7.0 occur at the equivalence point? I. Strong acid and strong base II. Weak acid and strong base III. Strong acid and weak base A. II and III B. III only C. I only D. II only

C. I only

Which of these conjugate acid-base pairs must be used to prepare a buffer with pH near 7.15? A. Formic acid and sodium formate (pKa 3.74) B. Succinic acid and sodium succinate (pKa 5.64) C. Glycylglycine and sodium gycylglycate (pKa 8.35) D. Sodium dihydrogen phosphate and sodium phosphate (pKa2 7.20)

D. sodium dihydrogen phosphate and sodium hydrogen phosphate (pKa 7.20)

What is the percent yield if 0.85 g of acetylsalicylic acid (aspirin) is obtained from the reaction of 1.00 g of salicylic acid with excess acetic anhydride? A. 65% B. 77% C. 85% D. 91%

A. 65%

Which piece of laboratory apparatus is not used for the purpose listed? A. Aspirator - measure height B. Buret - measure volume C. Calorimeter - measure thermal energy change D. Dessicator - store samples in dry conditions

A. Aspirator - measure height

Which of the following should be done before using an analytical balance? A. Clean the balance and remove any sample residue B. Determine the sensitivity of the balance using a calibration weight C. Check the level of the balance by adjusting the air bubble D. All of the above

D. All of the above

Which of the following statements is correct? A. Solid reactants can be weighed directly on the pan of an analytical balance B. The weight of a liquid is approximately equal to its density C. Solid reactants can be transferred to a reaction flask using a metal spatula D. Volatile liquids can be weighed by first recording the mass of the capped empty vial

C. Solid reactants can be transferred to a reaction flask using a metal spatula

Which would be most suitable for measuring 2.7 mL of ethanol for addition to a reaction with acidified dichromate? A. 10-mL graduated cylinder B. 10-mL volumetric flask C. 10-mL volumetric pipet D. 10-mL beaker

A. 10-mL graduated cylinder

What is the reading of the buret shown? A. 30.20 mL B. 30.25 mL C. 30.30 mL D. 31.75 mL

C. 30.30 mL

When a liquid is delivered from a volumetric pipet a small amount is typically retained in the tip. How should a student proceed in order to deliver the volume of liquid stated on the pipet? A. Leave the small amount in the tip. B. Use a pipet bulb to expel the remaining droplet. C. Shake the pipet to dispense the amount left in the tip. D. Draw the liquid above the line to compensate for the amount that remains in the tip.

A. Leave the small amount in the tip.

What is the correct procedure for dispensing liquids using a volumetric pipet? A. Immerse pipet, lift with finger on top, drain to mark, then drain remaining liquid. B. Immerse pipet, lift with finger on top, drain to mark, then gently blow out residual liquid with a pipet bulb. C. Submerge tip, suction with pipet bulb to above mark, cover top with finger, drain to mark, then drain remaining liquid. D. Submerge tip, suction by mouth to mark, then drain contents.

C. Submerge tip, suction with pipet bulb to above mark, cover top with finger, drain to mark, then drain remaining liquid.

When equal volumes of the following pairs of liquids are mixed thoroughly and allowed to stand, which pair is most likely to separate into two layers? A. Ethanol and methanol B. Carbon tetrachloride and methanol C. Hexane and pentane D. Carbon tetrachloride and hexane

B. Carbon tetrachloride and methanol

Cyclohexane and water can be separated by using a separatory funnel. Which property contributes to this separation? A. Cyclohexane and water are immiscible B. Cyclohexane has a lower viscosity than water C. Cyclohexane has a greater molar mass than water D. Cyclohexane has a greater vapor pressure than water

A. Cyclohexane and water are immiscible.

When selecting a solvent for purifying a material by crystallization, which of the following is not a consideration? A. Solubility B. Vapor pressure C. Reactivity D. Polarity

B. Vapor pressure

What is the key step in the recrystallization process? A. Taking the melting point of wet crystals B. Dissolving the solid in a large quantity of cold solvent C. Allowing the hot solution to cool slowly and letting crystals grow D. Removing soluble impurities by vacuum filtration

C. Allowing the hot solution to cool slowly and letting crystals grow.

Which of the following factors does not affect the boiling point of a substance? A. Atmospheric pressure B. Altitude C. Nature of intermolecular force D. Mass of the substance

D. Mass of the substance

A round-bottom flask, a condenser, a heat source, and clamps are typically assembled in the lab for which of the following procedures? A. Distilation B. Filtration C. Reflux D. Crystallization

C. Reflux

Aqua regia, the reagent used to dissolve gold, is a 3:1 mixture of which acids? A. Hydrochloric and sulfuric acids B. Hydrofluoric and nitric acids C. Hydrochloric and nitric acids D. Perchloric and sulfuric acids

C. Hydrochloric and nitric acids

What is the proper way to dispose of a two milliliter sample of hexane after completing experiments with it? A. Return it to the solvent bottle B. Place it in a waste bottle with compatible organic materials C. Flush it down the drain with large quantities of water D. Pour it on a solid adsorbent so it can be thrown away with solid waste

B. Place it in a waste bottle with compatible organic materials.

A student is cleaning a buret in preparation for a titration in which the buret will be filled with 0.100 M NaOH. What should be used for the final rinse of the buret? A. Ethanol B. Distilled water C. 0.100 M HCl D. 0.100 M NaOH

D. 0.100 M NaOH

Concentrated hydrochloric acid is 12 M and haas a density of 1.18 g/mL. What is the weight percent of concentrated HCl (36.45 g/mol) A. 5.1 B. 14 C. 37 D. 98

C. 37

A standard solution of barium hydroxide is 0.250 M. What volume of 0.200 M nitric acids would be required to neutralize 10.0 mL of the barium hydroxide solution? A. 10.0 mL B. 25.0 mL C. 30.0 mL D. 20.0 mL

B. 25.0 mL

A solution is prepare by dissolving 10.00 g of salt in 90.00 g of water. What additional information is required to calculate the molarity of a solution? I. Molar mass of the salt II. Density of the solution A. I only B. II only C. Both I and II D. The molarity cannot be determined even with both I and II

C. Both I and II

An analyst discovers that the analytical balance used in a test was improperly calibrated. What type of error does this represent? A. Systematic error B. Random error C. Gross error D. Cannot be determined

A. Systematic error

An analyst repeatedly weighs a sample on an analytical balance. Each time, the reading varies slightly (0.1221 g, 0.1224 g, 0.1220 g), even though no changes are made to the sample or conditions. What is the most likely cause of this variation? A. Systematic error due to bias in the balance B. Random error due to environmental fluctuations C. Gross error from misrecording the mass D. Calibration error in the balance

C. Gross error due to clumsy behavior and poor lab practice

While performing a titration to determine the concentration of an acid, a student knocks over the buret stand partway through the experiment. Some of the titrant spills, and the student hastily tries to estimate how muh was lost based on memory instead of repeating the experiment. What type of error has occurred? A. Random error due to changes in flow rate B. Systematic error due to incorrect technique C. Gross error due to clumsy behavior and poor lab practice D. Instrumental error due to unstable environment

C. Gross error due to clumsy behavior and poor lab practice

A chemist is analyzing caffeine drinks using HPLC. A calibration curve is then used to determine caffeine concentration in the drink sample. What type of quantification method is being used? A. Standard addition B. Internal standard C. External standard D. Matrix matching

C. External standard

Which graph shows instrument's response plotted against standard solution concentrations? A. Linear range B. Calibration curve C. Dynamic range D. Linear dynamic range

B. Calibration curve

In an electrochemical cell, the anode is a strip of magnesium. Which of the following metals is most likely the cathode? A. Zinc B. Copper C. Potassium D. Sodium

B. Copper

Which of the following processes does not involve an electrochemical cell? A. Electroplating silver onto a spoon B. Charging a rechargeable battery C. Using a salt bridge to complete a redox circuit D. Heating a solution to speed up a reaction

D. Heating a solution to speed up a reaction do.

What is the main function of the glass membrane in a pH electrode? A. Maintains electrical neutrality in solution B. Generates a potential based on hydroxide ion concentration C. Conducts electricity between reference and sample D. Responds selectively to hydrogen ion concentration

D. Responds selectively to hydrogen ion concentration

Carbon monoxide is a common gaseous pollutant emitted from automobile exhaust. Which of the following reagent is used in gas analysis to absorb CO quantitatively? A. Calcium monoxide B. Pyrogallic acid C. Copper (I) chloride D. Sodium hydroxide

C. Copper (I) Chloride

In TLC, the relative adsorption of the components in a mixture is expressed in terms of the: A. Retardation factor B. Solubility factor C. Acceleration factor D. Acceleration and retardation factor

A. Retardation factor

The chromatographic or TLC plate is typically made of: A. Wood B. Fibro C. Metal D. Glass

D. Glass

In chromatography, the relative solubility of a solute in both the stationary and mobile phase determine the: A. Rate of disappearance of solute B. Rate of movement of solvent C. Rate of disappearance of solvent D. Rate of movement of solute

D. Rate of movement of solute ## Footnote The solubility affects how quickly a solute travels through the chromatographic medium.

The elution power of a solvent is primarily determined by: A. Its overall polarity B. Polarity of the stationary phase C. Nature of the sample components D. All of the above

D. All of the above ## Footnote The overall polarity, polarity of the stationary phase, and nature of sample components all influence elution power.

In column chromatography, components of a sample are eluted in the order of: A. Increasing polarity and decreasing distribution of ratio B. Decreasing polarity and increasing distribution ratio C. Increasing polarity and increasing distribution ratio D. Decreasing polarity and decreasing distribution ratio

C. Increasing polarity and increasing distribution ratio ## Footnote This order allows for effective separation based on the interactions of components with the stationary phase.

Which of the following cannot be used as an adsorbent in column chromatography? A. Silica gel B. Alumina C. Magnesium oxide D. Potassium permanganate

D. Potassium permanganate ## Footnote Potassium permanganate is not typically used as an adsorbent due to its reactive nature compared to the other options.

Benzene has smaller distribution ratio (D) in squalene than cyclohexane. Squalene is an aliphatic hydrocarbon. Based on this, what is the order of elution of the two compounds in GC? Note: D = concentration of sample in stationary phase/ concentration in mobile A. Benzene will be eluted first B. Cyclohexane will be eluted first C. Cannot be determined D. The two peaks will overlap

A. Benzene will be eluted first

An environmental chemist is analyzing air samples to detect low concentration of pollutant gases. Which of the following techniques would be most appropriate for this type of analysis? A. Paper chromatography B. Gas-Liquid chromatography C. Gas-Solid chromatography D. Thin layer chromatography

C. Gas-Solid chromatography

Ion exchange chromatography is used for all of the following applications, except: A. Separation of sugars B. Separation of amino acids C. Separation of rare earth elements D. Separation of trace metal ions

A. Separation of sugars

Which of the following is not a typical application of colorimeter? A. Measuring ink formulations B. Testing cosmetics C. Determining solution concentration D. Identifying chemical composition

D. Identifying chemical composition

A hollow cathode tube lamp is necessary in AAS because: A. Atom's absorption band is narrow B. Cathode lamps cost less to run C. Other lamps don't give enough light D. Other lamps ionize the sample

A. Atom's absorption band is narrow

Which of the following is an application of molecular spectroscopy? A. All of the given answers B. Understanding the basis color C. Structural investigation D. Study of excited reaction products

A. All of the given answers

Which of the following statements about molecular spectra is correct? A. Molecular spectra are more complex than atomic spectra B. Molecular spectra arise from transitions between molecular energy levels. C. Molecular transitions can involve electronic, vibrational, and rotational changes D. All of the given choices

D. All of the given choices

What is the typical wavelength range of UV radiation in the electromagnetic spectrum? A. 400nm to 700nm B. 10nm to 400nm C. 700nm to 1mm D. 0.01nm to 10nm

B. 10nm to 400nm

Which of the following is not a characteristic of chromophores? A. They may contain extensive conjugated double bonds B. They contain unsaturated functional groups C. They are added to compounds that do not strongly absorb light in the UV-Visible region D. They absorb strongly at 800 nm

D. They absorb strongly at 800 nm

Which is most likely to exhibit a strong IR absorption at 1700cm-1 due to a C=O stretch? A. Ethanol B. Acetone C. Ethene D. Aniline

B. Acetone

Which will be the most effective at distinguishing between pure samples of 79Br and 81Br isotopes? A. Infrared spectroscopy B. Mass spectroscopy C. UV-Vis spectroscopy D. Heat calorimetry

B. Mass spectroscopy

Eval Exam 1 Flashcards

(75 cards)