What is the plot of current versus applied potential in voltammetry called?

Who developed the earliest voltammetric technique, and what was it called? Fill in the blank: The earliest voltammetric technique is ______, developed by ______ in the early 1920s.

In voltammetry, what is the function of the auxiliary electrode?

In voltammetry, the reference electrode is usually a SCE or a Ag/AgCl electrode.

Read the passage and answer the following: Which of the following materials can be used as a working electrode in voltammetric techniques?

In the hanging mercury drop electrode (HMDE), how is the mercury drop formed?

The dropping mercury electrode (DME) produces mercury drops at the end of the capillary tube as a result of ________.

Read the passage and answer the following: True or False: The static mercury drop electrode (SMDE) can be used as either a HMDE or a DME.

What is a mercury film electrode?

What is one major advantage of using mercury as a working electrode?

Mercury electrodes can be used at potentials more positive than approximately -0.3 V to +0.4 V versus the SCE.

What is an amalgam, and how is it formed when using mercury as a working electrode?

According to the passage, which materials can be used to construct solid electrodes?

Fill in the blank: The potential window for a Pt electrode extends from approximately +1.2 V to ____ V versus the SCE in acidic solutions.

Which type of electrode is fashioned into a disk and sealed into the end of an inert support with an electrical lead, as shown in Figure 11.36?

A solid electrode can replace a mercury electrode for many voltammetric analyses that require negative potentials.

What is the most important problem associated with solid electrodes as mentioned in the passage?

Refer to the diagram of the typical electrochemical cell for voltammetry. Which electrode is responsible for the oxidation or reduction of the analyte?

In voltammetry, the current from redox reactions at the working electrode and the auxiliary electrode is called a ________ current.

A faradaic current due to the analyte’s reduction is called a cathodic current.

Which of the following is used to remove dissolved O₂ from the solution in an electrochemical cell?

Electrochemical cells are available in a variety of sizes, allowing the analysis of solution volumes ranging from more than ____ mL to as small as ____ μL.

What is the effect of an anodic current at the working electrode?

Fill in the blank: The relationship between the concentrations of $$Fe(CN)6^{3-}$$ , $$Fe(CN)6^{4-}$$ , and the potential is given by the Nernst equation:

What is the standard-state potential for the $$Fe(CN)6^{3-}/Fe(CN)6^{4-}$$ redox couple?

Explain why surface concentrations are used instead of bulk concentrations when determining the equilibrium position for the redox reaction Fe(CN)3–6(aq) + e– ⇆ Fe(CN)4–6(aq) at the electrode’s surface.

Fill in the blank: If the initial concentration of Fe(CN)6^3- is 1.0 mM and Fe(CN)6^4- is absent, switching the potential to +0.356 V will result in [Fe(CN)3–6]x=0 = [Fe(CN)4–6]x=0 = _______.

What is the standard electrode potential (E°) for the $$Fe(CN)6^{3-}/Fe(CN)6^{4-}$$ redox half-reaction?

What creates the driving force that transports $$Fe(CN)6^{4-}$$ away from the electrode and $$Fe(CN)6^{3-}$$ to the electrode?

The analyte’s concentration at the electrode is always the same as its concentration in bulk solution.

Explain why a faradaic current continues to flow during the $$Fe(CN)6^{3-}/Fe(CN)6^{4-}$$ redox reaction at the electrode.

What process is illustrated in this figure?

What are the two factors that contribute to the rate of the electrochemical reaction according to the passage?

Which of the following is NOT a mode of mass transport that affects the rate at which reactants and products move toward or away from the electrode surface?

Diffusion occurs whenever the concentration of an ion or molecule at the surface of the electrode is ________ from that in bulk solution.

At what time is the concentration of $$Fe(CN)6^{3-}$$ at the electrode surface zero?

Fill in the blank: The dashed red line in the diagram shows the extent of the _______ at time t3.

Which of the following is NOT a method of creating convection in an electrochemical cell?

Convection occurs when we mechanically mix the solution, carrying reactants toward the electrode and removing products from the electrode. The most common form of convection is stirring the solution with a stir bar. Other methods that have been used include rotating the electrode and incorporating the electrode into a flow-cell.

Explain why the concentration of $$Fe(CN)6^{3-}$$ at the electrode surface decreases to zero after applying the potential.

What is migration in the context of mass transport in electrochemistry?

Unlike diffusion and convection, migration only affects the mass transport of ________ particles.

In the limit where diffusion is the only significant form of mass transport, the current in a voltammetric cell is equal to i = nFAD(Cbulk–Cx=0)δ(11.36). What does 'n' represent in this equation?

Migration can be eliminated by adding a high concentration of an inert supporting electrolyte.

Which of the following is NOT a method to eliminate convection in an electrochemical cell?

What is the typical thickness of a diffusion layer when fluid moves past an electrode, as mentioned in the passage?

Based on the diagram, which form of mass transport is significant close to the electrode’s surface?

If electron transfer kinetics are fast, the redox reaction is ________ and the Nernst equation applies.

If electron transfer kinetics are sufficiently slow, the system is:

In addition to current resulting from redox reactions (faradaic current), the current in an electrochemical cell includes other, nonfaradaic sources.

What is the term used for the small, short-lived current that occurs every time we change the electrode’s potential?

The migration of ions in response to the electrode’s surface charge leads to the formation of a structured electrode-solution interface called the ________.

Residual current in an electrochemical cell only consists of charging current.

Which of the following is NOT a component of residual current in an electrochemical cell?

How many common shapes for voltammograms are there, according to the text?

For the voltammogram in Figure 11.42a, the current increases from a background residual current to a ________ current, iₗ.

Because the faradaic current is inversely proportional to δ (equation 11.36), a limiting current can only occur if the thickness of the diffusion layer remains constant because we are ________ the solution.

As shown in Figure 11.42b, the resulting voltammogram has a ________ current instead of a limiting current.

For the voltammograms in Figures 11.42a and 11.42b, we measure the current as a function of the applied potential.

What does the red arrow labeled 'i_l' represent in the context of the current vs potential graph?

What does the red arrow labeled 'i_p' represent in the context of the current vs potential graph?

What does the red arrow labeled 'Δi_p' represent in the context of the change in current vs potential graph?

What does the dashed red line show in Figure 11.42?

Fill in the blank: In voltammetry, the limiting current (i_l) is a linear function of the concentration of ______ in bulk solution.

What is the equation for the current (i) at the working electrode when O is present in bulk solution and the solution is being stirred?

What is the constant K_O equal to in the context of determining concentration in voltammetry?

To extract the standard-state potential from a voltammogram, which equation do we need to rewrite for reaction 11.37?

Fill in the blank: When the current, i, is half of the limiting current, il, the equation is i = ____ × il.

What is the assumption made about the initial solution when simplifying the equation for [R]bulk?

Which variable in the equations represents the limiting current?

What is the half-wave potential (E1/2) in voltammetry?

What does the limiting current (i) represent in a voltammogram?

Write the equation for the half-wave potential (E1/2) as given in the worksheet.

In voltammetry, what are the three important experimental parameters under our control?

What is the first important voltammetric technique to be developed that uses the dropping mercury electrode as the working electrode?

In normal polarography, what is measured while applying a linear potential ramp to the electrochemical cell?

Fill in the blank using the passage: The limiting current in polarography is also called the ______ current.

Based on the passage and Figure 11.44: The oscillations in the current during polarography are a result of the growth of the Hg drop, which leads to a time-dependent change in the area of the working electrode.

According to the passage, the limiting current in polarography can be measured using either the maximum current (imax) or the average current (iavg).

Fill in the blank: The half-wave potential, E1/2, provides qualitative information about the ________ reaction.

Which of the following is a constant in the equations for polarography?

In normal pulse polarography, the faradaic current is greater than in polarography, resulting in better sensitivity and smaller detection limits.

Fill in the blank: In differential pulse polarography, the current is measured twice per cycle: for approximately 17 ms before applying the pulse and for approximately 17 ms at the ______ of the cycle.

What is the typical experimental condition for the pulse-time (tp) in both normal and differential pulse polarography?

What does the first derivative of a sigmoidal function look like?

Read the passage below and answer the following question: Other forms of pulse polarography include staircase polarography and square-wave polarography. One advantage of square-wave polarography is that we can make τ very small—perhaps as small as 5 ms, compared to 1 s for other pulse polarographies—which can significantly decrease analysis time. What is one advantage of square-wave polarography over other forms?

How long does it take to complete the scan using square-wave polarography with the given parameters?

Name two types of compounds that can be analyzed using polarography.