ACS Analytical Chemistry Practice Exam

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• Cathode definition: The half cell that electrons flow into and where reduction occurs.
• In Case 2B, which expression defines Tcalc?
• Ecell = E+ - E-.
• Volume ppm is defined as the ratio of solute volume to solution volume multiplied by what factor?
• What is [H3O+] in terms of pH?
• What is analyte?
• Which statement correctly identifies Kf' in the context of EDTA titration calculations?
• When combining uncertainties for addition or subtraction, what is the standard approach?
• What is a zwitterionic form?
• What is the value of Kw for the autoprotolysis of water?
• What is a first order indicator electrode?
• Using the special tool, which expression correctly gives [H3O+]?
• In balancing a half-reaction, which step directly balances the number of electrons?
• In order to have a complete half-cell reaction, you must have
• In a charge balance example, how should the nitrate ion NO3^4- be represented?
• In EDTA complexometric titration, what is a masking agent?
• In normal-phase liquid chromatography, which relationship between stationary and mobile phase polarity is correct?
• What is a common drawback of using permanganate as a titrant in redox titrations?
• In back titration, which statement best describes how the metal concentration is determined?
• How do you find the K value in half-cell reactions?
• What is a general purpose of performing an EDTA titration?
• In the described redox titration, is it possible to locate a 0 mL point?
• Which expression correctly represents the Nernst equation for a redox couple at 25°C?
• If a current of 4 A flows for 5 s, the transferred charge is:
• Which of the following statements is true about normal-phase chromatography?
• How is the gravimetric factor defined?
• At halfway to the equivalence point in an EDTA titration, which procedure is described to determine the remaining metal concentration?
• In solution concentration, weight percent is defined as which expression?
• When Q equals Ksp for a sparingly soluble salt, what is the system's state?
• In polyprotic acid-base titration, what is the pH at half way to the first equivalence point?
• What is the value of the equilibrium constant for the reverse reaction of a base reacting with water (i.e., base on reactants, conjugate acid and hydroxide on products)?
• Which expression gives the energy of a photon in terms of wavelength using Planck's constant and the speed of light?
• If the voltmeter readout is negative, electrons flow from which direction?
• What is the standard electrode potential (E°) of the Standard Hydrogen Electrode?
• What is the primary measurement used in a gravimetric method to determine the amount of analyte?
• What is the unit for ppm simplified?
• Which statement about the retention factor formula is true?
• Which equation expresses the dilution relation M1V1 = M2V2?
• What is the unit for pptr simplified?
• Which phrase best captures the polarity-based solubility principle described in chromatography?
• In a neutral solution at standard conditions, the concentrations of H3O+ and OH- are:
• Which type of agent is typically used as the titrant in redox titrations?
• Which statement is true for systematic error?
• Which is the correct form of the Henderson-Hasselbalch equation?
• A monodentate ligand is defined by having how many lone pairs on the donor atom?
• What are the units of Planck's constant?
• In the polyprotic-acid fraction expressions, what is the common denominator used for all alpha values?
• At the equivalence point of a diprotic titration, the pH is given by which expression?
• EDTA is best described as which type of ligand?
• Which expression defines volume percent?
• For a polyprotic acid, the fraction alpha A2- is given by which expression? Denominator is ([H3O+]^2+[H3O+]K1+K1K2).
• Under the zwitterionic form simplification, the [H3O+] expression reduces to which form?
• Which prefix has the value 10^-1?
• What determines whether Case 2A or Case 2B is used?
• According to the source, how is ppt (parts per trillion) expressed?
• T-test 1 Tcalc is defined as (sqrt(n) × |known value − calculated mean|) / standard deviation.
• Which cell requires external energy to drive non-spontaneous reactions?
• If the energy of a photon is expressed as E = h f, what happens to the energy when frequency doubles (h constant)?
• A small Ksp indicates what about a sparingly soluble salt?
• In a dissolution (Ksp) equilibrium, the dissolution involves a transition from what to what?
• What is the minimum possible value of relative retention alpha in chromatography?
• Which prefix represents 10^-9?
• Which statement correctly distinguishes a Brønsted-Lowry acid from a Brønsted-Lowry base?
• In a monoprotic acid titration with 1:1 stoichiometry, which statement is true about equivalence?
• Volume percent is defined as the ratio of solute volume to solution volume multiplied by 100. Which option represents this definition when written as a formula?
• Which sequence describes the steps to solve a back titration?
• Which of the following statements about titration is the most appropriate method to determine pH at the equivalence point of a titration?
• One mole of electrons carries how many coulombs?
• What is a second order indicator electrode?
• For a monoprotic acid HA in solution, the fraction corresponding to the conjugate base A- is given by which expression?
• What can be used to maintain electroneutrality in a complete half-cell reaction?
• In Beer's Law, absorbance is proportional to distance and concentration by a constant. Which statement is true?
• Which expression correctly describes the propagation of uncertainty for a quantity obtained by multiplying and dividing several measurements?
• Which statement best describes the function of the salt bridge in a galvanic cell?
• Ttable is used to look up the critical value from the t-distribution for a given degrees of freedom and confidence level.
• What is chromatography?
• Ksp stands for which term?
• Which equation expresses [metal] in terms of alpha_m and C_metal?
• At the equivalence point of a monoprotic acid–base titration, which factor most directly determines the pH of the solution?
• The half cell with the higher Eo tends to be
• Which symbol represents the metal-EDTA complex commonly formed in this titration?
• Which expression equals the retention factor k in chromatography?
• The T-test used in Case 2A uses which formula for Tcalc?
• In the equation q = nF, what does n represent?
• Which statement about standard electrode potential E° is true?
• Which term describes the unknown species whose quantity you aim to determine in a titration experiment?
• What term describes the experimental volume of titrant required to completely react with the analyte, as indicated by a physical change in the solution?
• In reverse-phase liquid chromatography, which statement is true?
• In the equations, HL denotes which species?
• A standard solution is typically used to determine what quantity in titration analysis?
• Which prefix represents 10^-3?
• Which statement best describes electrode potential?
• Which prefix represents 10^3?
• Percent Transmittance is defined as:
• Which statement best describes systematic error?
• Which statement best defines the equivalence point in a titration?
• What is the unit for ppb simplified?
• Liquid chromatography is used primarily for samples that are
• Which ligand is hexadentate?
• If Q > Ksp for a sparingly soluble salt, what happens as the system approaches equilibrium?
• Which statement describes an acid?
• Which endpoint is considered better in a polyprotic acid-base titration curve?
• If the forward equilibrium constant is k, what is the equilibrium constant for the reverse reaction?
• In a direct titration, which statement is true?
• Which of the following best defines titration error?
• In Case 2, Fcalc is defined as which ratio?
• Which expression describes the propagation of uncertainty for a product or quotient of measurements?
• Which statement describes a base?
• At the start of an acid-base titration, the pH is given by which expression?
• What does precision refer to in analytical measurements?
• Which form correctly represents Tcalc as presented?
• Which exponent corresponds to the prefix pico?
• I = q/s. What is the unit of current?
• What is equivalence point?
• Which unit is used for pptr simplified?
• A standard solution is defined as what?
• Which statement correctly distinguishes monodentate and multidentate ligands?
• What is an extraction?
• In Case 1, if Tcalc < Ttable, what is the stated conclusion?
• Which statement best describes random error?
• What is the common ion effect?
• Which statement best describes how gas chromatography works?
• Which formula represents buoyancy correction?
• Which species is used to balance hydrogen atoms in acidic solution during half-reaction balancing?
• What is the first step in balancing a half-reaction equation?
• What is titrant?
• Why are auxiliary complexing agents added to EDTA titrations?
• T-test 1 equation is true value = mean ± (time × standard deviation)/sqrt(number of measurements).
• Under standard conditions, Ecell equals E° when the reaction quotient Q equals
• Which expression defines pH?
• What is the function of a salt bridge in a galvanic cell?
• Planck's constant has the value 6.626 x 10^-34. Which unit combination correctly accompanies this value?
• The pooled variance used in Case 2A is defined as:
• In the transmittance equation P/Po, Po represents what?
• Relative uncertainty is defined as the ratio of absolute uncertainty to the magnitude of the measurement.
• In the liquid junction potential expression, Ai represents what?
• T-test Case 1 is used to measure a sample of known composition.
• Which cell operates spontaneously?
• What is the meaning of the prefix pico?
• Gas chromatography is primarily used for which type of samples?
• What constant describes the strength of an acid in water on the reactants side?
• Indicators are considered to be which of the following?
• Which of the following is NOT a characteristic of an ideal primary standard?
• Which statement correctly describes reverse-phase chromatography?
• Case 3 uses Sd to measure dispersion around the mean. Which statement is true?
• Why is alpha equal to 1 undesirable in practice?
• Which statement describes the central 68% interval for a normal distribution?
• For log10(205.5), how many decimal places are required to report the mantissa with the appropriate significant figures?
• According to Beer's Law, absorbance is proportional to concentration and path length. Which expression best represents this relationship?
• Variance is defined as the square of which quantity?
• Which expression represents molarity?
• The best reducing agents have
• In the equation q = nF, what does F represent?
• In a galvanic (voltaic) cell, electrons flow in which direction relative to the labeled electrodes E- and E+?
• The speed of light in vacuum can be expressed as c = λ f. Which option correctly states this relationship?
• In an electrolytic cell, electrons flow in the non-spontaneous direction relative to E- and E+?
• According to significant figures rules for logarithms and antilogarithms, the number of significant figures in the logarithm equals what?
• What does Ttable represent?
• Which expression defines the condition at equivalence in an EDTA titration?
• Which prefix represents 10^-2?
• For a polyprotic acid with two dissociation steps, the fraction alpha H2A is given by which expression? Denominator is ([H3O+]^2+[H3O+]K1+K1K2).
• At the equivalence point, which calculation step is used to obtain -log[metal]?
• In a galvanic setup with a liquid junction potential, Ejunction is described by an expression involving z1 and the ratio of activities. What does z1 represent?
• Which description matches the anode half-cell liquid junction potential?
• Which balanced equation correctly represents the autoprotolysis of water?
• When correcting absorbance for dilution, the corrected absorbance equals the measured absorbance multiplied by the ratio of total volume to initial volume. Which expression correctly gives A_corr?
• What are indicator electrodes?
• Which statement best describes liquid junction potential problems?
• To determine Q for a dissolution reaction, which statement is correct?
• What constant describes the strength of a base in water on the reactants side?
• Which is the correct value for Planck's constant?
• With the simplified special tool equation for [H3O+], is [H3O+] independent of the concentration of HL?
• If the equilibrium concentration of a metal ion is 1.0 x 10^-6 M, what is pMETAL?
• If [H3O+] = 1.0 x 10^-7 M, what is [OH-] at 25°C?
• For the reverse reaction of an acid reacting with water on the products side, what is the equilibrium constant?
• After solving ICE tables in the redox titration workflow, what is the next calculation described?
• In a Gaussian distribution, approximately what fraction of measurements lie within one standard deviation of the mean?
• What pH condition is preferred when performing an EDTA titration to maximize the complex stability (Kf')?
• For polyprotic titrations involving the zwitterionic form, which step is used to determine [H3O+]?
• In a gravimetric titration involving a sparingly soluble product, which sequence describes endpoint determination using Q values and Ksp?
• The best oxidation agents have
• Absorbance is defined as what function of transmittance?
• In chromatography, what is tM?
• Chelate effect is defined as what?
• Kw expressed in terms of Ka and Kb for a conjugate acid-base pair is equal to which expression?
• Indirect titration is characterized by which statement?
• In an EDTA titration, at 0 mL of titrant added, which quantity is used to express the metal concentration?
• If Fcalc > Ftable, you should use which case?
• In chromatography, what is said about Ka and Kb?
• What is the Ka relationship for chromatography?
• What is one common limitation of semi-permeable membranes in this context?
• If a reaction has a very large equilibrium constant K, toward which side is the equilibrium pushed?
• A multidentate ligand is described as having how many donor pairs?
• The prefix femto represents which factor?
• Anode definition: The half cell from which electrons originate during oxidation.
• In the equilibrium constant expression for a reaction in aqueous solution, which phases are omitted?
• What primary measurement is used to determine the amount of analyte in a gravimetric method?
• What does the formation constant Kf describe in EDTA complexation?
• The ratio V_total / V_initial is commonly called what in dilution calculations?
• If the voltmeter readout is positive, in which direction do electrons flow?
• Ksp is defined as
• For the Grubbs test, the statistic G is defined as the absolute deviation of the questionable value from the sample mean divided by the sample standard deviation. Which of the following represents G?
• Which prefix represents 10^-6?
• In the redox titration procedure, how is Ecell determined after you have the necessary concentrations?
• After the equivalence point in an EDTA titration, which quantity is determined by solving the ICE table and taking -log[metal]?
• The pH using the special tool equation is?
• The pooled standard deviation is computed as:
• Which expression correctly represents alpha_m for a complexation titration as a function of L when it is described by a polynomial series in L?
• Which statement best describes a primary standard in titration analysis?
• Which expression correctly represents the propagation of uncertainty for addition or subtraction?
• Reference electrodes are used to
• What is the difference between an extraction and chromatography?
• If you dilute a solution 10-fold (V2 = 10 V1), which statement is true about the new concentration M2?
• For Case 2A, which expression defines Tcalc?
• When absorbance is corrected for dilution and total volume increases, what happens to the corrected absorbance if initial volume stays the same?
• In the T-test notation, what does the symbol n denote?
• At half-way to the equivalence point, which statement is true regarding pH and pKa?
• In constructing a charge balance equation, which is the correct procedure?
• What is the standard electrode potential (E°) of the Silver-Silver Chloride Electrode?
• What is the principle of extraction?
• For a polyprotic acid, the fraction alpha HA- is given by which expression? Denominator is ([H3O+]^2+[H3O+]K1+K1K2).
• According to the described procedure, what is the first step in performing a redox titration?
• At the start of an auxiliary complexing titration (0 mL added), which method is used to determine the metal concentration?
• Which description matches the cathode half-cell liquid junction potential?
• Resolution is defined as R = (tR1 - tR2) / (0.5 (w2 + w1)). What is the minimum acceptable value for R?
• A weak acid is defined by a Ka value of
• Autoprotolysis of water becomes significant when the total concentration of strong species is below what value?
• In polyprotic titrations, a common simplification is valid when Ka1 is how much larger than Ka2?
• One electron carries how many coulombs?
• In the context of an auxiliary complexing titration, which statement describes how Kf'' is used?
• In the Anode Half Cell, what happens to the solution when current flows out?
• The half cell with the lower Eo tends to be
• What is the retention factor equation in chromatography?
• What should you check after balancing a half-reaction to ensure correctness?
• Why is a basic medium typically used during EDTA titration?
• T-test Case 3 is used to compare individual differences of an unknown sample, with two sets of data analyzed by both methods.
• At half-way to the equivalence point in an auxiliary complexing titration, which sequence is used to determine [metal]?
• In Case 3, Sd is defined as which expression?
• Which statement about weak acids is false?
• The Henderson-Hasselbalch equation is most useful for describing the pH of which system?
• Which expression defines molarity?
• How many significant figures are present in log10(205.5) according to standard rules?
• Which sequence correctly represents the order of steps described for the redox titration procedure?
• Which statement correctly describes liquid junction potentials?
• In electrochemical cells, the cathode is the site of reduction.
• The volume of titrant at equivalence for a titration with a 1:1 stoichiometry is given by which expression if the analyte has concentration M_A and volume V_A and the titrant has concentration M_T?
• Which expression defines volume ppm?
• In the Cathode Half Cell, what happens to the solution when current flows in?
• Which expression defines k for a reaction in aqueous solution?
• Gas chromatography is most appropriate for separating which type of substances?
• Which unit is used for ppt simplified?
• For a monoprotic acid HA in solution, the fraction of the undissociated species HA is given by which expression?
• In chromatography retention measurements, what does tR represent?
• What is the Henderson-Hasselbalch equation?
• What is the standard formula for chromatographic resolution R?
• Molar solubility is typically expressed in which units?
• Among the listed reference electrodes, which has the highest standard potential?
• Relative retention alpha can be expressed as which of the following?
• What is the unit for ppt simplified?
• How is the gravimetric factor defined?
• Which statement best defines accuracy in measurement?
• Which statement describes a reduction half-reaction?
• Faraday constant is expressed in which units?
• Which statement best describes Kf' in the EDTA system?
• In Case 2A, if Tcalc < Ttable, what is the conclusion about the two data sets?
• If Fcalc < Ftable, you should use which case?
• Kw is the product of the hydronium and hydroxide ion concentrations. Which expression is correct?
• In the Q-test for detecting an outlier, Q is defined as the gap divided by the range. If the calculated Q exceeds the Q-table value, what is the conclusion at 90% confidence?
• Which statement describes the equivalence point in EDTA titration?
• At very high pH, which species dominates for a polyprotic acid?
• In Y^4-, what does the superscript 4- indicate?
• Which description correctly explains how to obtain -log[metal] at halfway to equivalence?
• If 99% of the solute precipitates, what is the remaining molarity of dissolved solute immediately after precipitation?
• Which expression correctly relates photon energy to wavelength using Planck's constant and the speed of light?
• For a sparingly soluble salt dissolving according to MX(s) ⇌ M^n+ + X^m-, if Q < Ksp, in which direction does the reaction proceed?
• Which parameter is kept constant by reference electrodes in electrochemical measurements?
• Which description best defines a carrier gas in GC?
• Which prefix has the value 10^-2?
• Ejunction depends on which of the following relationships between ion activities?
• Solubility and molar solubility units relationship
• When is Henderson-Hasselbalch appropriate to use?
• In the Grubbs outlier test, what must be included when calculating the G statistic?
• What is the purpose of calculating the reaction quotient Q in Ksp contexts?
• In a problem, which statement is true about balance equations?
• At half-way to the equivalence point in a titration, which statement is true about pH and pKa?
• Which of the following correctly expresses pKw in terms of pH and pOH?
• In the equation for [H3O+] involving Kw, what does Kw represent?
• Denticity terminology: which description applies to EDTA?
• In Case 2B, if Tcalc < Ttable, what is the conclusion about the two data sets?
• According to the material, the mean is the true value plus or minus time multiplied by the standard deviation.
• The EDTA complexation stoichiometry is always 1:1.
• How is EDTA written in a stoichiometric reaction?
• What is the standard electrode potential (E°) of the Saturated Calomel Electrode?
• T-test Case 2 is used to compare replicate measurements of an unknown sample.
• A reaction with a very small equilibrium constant K is expected to shift toward which side?
• Which statement best describes a mass balance equation?
• Which species is used to balance oxygen atoms when balancing a half-reaction in acidic solution?
• Which statement best describes how photon energy depends on frequency, given E = h f?
• A good semi-permeable membrane in this context will have what characteristic for the partition coefficient K?
• If Transmittance is 0.5, Percent Transmittance is:
• Which expression correctly represents the fraction alpha HA- in a polyprotic acid system, using the denominator ([H3O+]^2+[H3O+]K1+K1K2)?
• Which prefix corresponds to 10^3?
• Halfway to the second equivalence point, the pH equals which constant?
• What is the reaction stoichiometry for EDTA?
• The equivalence point in a redox titration is conceptually the same as which point in an acid-base titration?
• In the margin of error expression for the T-test, which quantity represents the margin of error in the equation?
• For Case 1, if Tcalc > Ttable, the actual value isn't in the range and it is bad.
• Common units for expressing solubility are:
• Which expression correctly represents weight percent?
• Which exponent corresponds to the prefix femto?
• In the expression for alpha_m, B is described as:
• Which Ka value would indicate a relatively stronger weak acid?
• If transmittance is 1, what is absorbance?
• Which equation represents the energy of a photon in terms of Planck's constant and frequency?
• Which expression defines ppm?