Question 1

Gold is produced electrochemically from an aqueous solution of Au(CN)₂^- containing an excess of CN^-.Gold metal and oxygen gas are produced at the electrodes.How many moles of O₂ will be produced during the production of 1.00 mole of gold?

Accepted Answer

The answer of Gold is produced electrochemically from an aqueous...

Question 2

Which of the following are incorrectly paired?

Accepted Answer

All of the pairings provided are correct. Alumina is indeed pure aluminum oxide, the Downs cell is used for electrolyzing molten sodium chloride to produce sodium, the Mercury cell is a method used in the chloralkali process to prevent contamination of sodium hydroxide (NaOH) by sodium chloride (NaCl), and the Hall-Heroult process is a major industrial process for smelting aluminum that uses cryolite to lower the melting point of alumina.

Question 3

Balance the following equation: Cr₂O₇²^- + I^- $\to$ Cr³⁺ + IO₃^- (acid)

Accepted Answer

The answer of Balance the following equation: Cr₂O₇²^- + I^-...

Question 4

If an electrolysis plant operates its electrolytic cells at a total current of 1.8 $\times$10⁶amp,how long will it take to produce one metric ton (one million grams)of Mg(s)from seawater containing Mg²⁺? (1 faraday = 96,485 coulombs)

Accepted Answer

The correct answer is A because 1.8 F1F1F1S1F1F1F10 10⁶amp = 1.8 × 96,485 C/s = 1.73 × 10⁸ C/s. To produce 1 metric ton of Mg(s), we need to pass 1 × 10⁶ g of Mg²⁺ through the electrolytic cells. The molar mass of Mg is 24 g/mol, so we need to pass 1 × 10⁶ g / 24 g/mol = 4.17 × 10⁴ mol of Mg²⁺. Each mole of Mg²⁺ requires 2 electrons, so we need to pass 2 × 4.17 × 10⁴ mol × 96,485 C/mol = 8.02 × 10⁸ C of charge. At a current of 1.73 × 10⁸ C/s, it will take 8.02 × 10⁸ C / 1.73 × 10⁸ C/s = 4.64 h to produce 1 metric ton of Mg(s).

Question 5

Balance the following equation: MnO₄^- + Br^- $\to$ MnO₂ + BrO₃^- (base)

Accepted Answer

The answer of Balance the following equation: MnO₄^- + Br^-...

Question 6

What mass of Ti(s)may be deposited from an aqueous TiCl₂ solution if a current of 2.50 A is applied to the solution for 365 s? ($\varepsilon$°_red(Ti²⁺/Ti)= -1.63 V,F = 96485 C/mol)

Accepted Answer

The mass of Ti deposited can be calculated using the formula: mass = (It/nF) * M, where I is the current (2.50 A), t is the time (365 s), n is the number of electrons transferred (2 for Ti^2+ to Ti), F is Faraday's constant (96485 C/mol), and M is the molar mass of Ti (47.87 g/mol). Plugging in these values gives approximately 0.226 g.

Question 7

If a constant current of 5.0 amperes is passed through a cell containing Cr³⁺ for 1.0 hour,how many grams of Cr will plate out onto the cathode? (The atomic mass of Cr is 51.996. )

Accepted Answer

The answer of If a constant current of 5.0 amperes...

Question 8

An unknown metal (M)is electrolyzed.It took 74.1 s for a current of 2.00 amp to plate 0.107 g of the metal from a solution containing M(NO₃)₃.Identify the metal.

Accepted Answer

First, we need to calculate the amount of charge that passed through the electrolytic cell using Faraday's Law:

Q = It
Q = (2 A) x (74.1 s)
Q = 148.2 C

Next, we can use the charge and the mass of the metal deposited to calculate the molar mass of the metal:

mol M = Q / nF

n = mass / molar mass

mol M = (148.2 C) / (1 mol e⁻/ 96485 C) x (0.107 g / M)

Solving for molar mass, we get:

M = 208.2 g/mol

Based on the answer choices, the closest match to this molar mass is Bi (which has a molar mass of 208.98 g/mol). Therefore, the unknown metal M is likely bismuth (Bi).

Question 9

A solution of MnO₄²^- is electrolytically reduced to Mn³⁺.A current of 8.07 amp is passed through the solution for 15.0 minutes.What is the number of moles of Mn³⁺ produced in this process? (1 faraday = 96,485 coulombs)

Accepted Answer

The answer of A solution of MnO₄²^- is electrolytically reduced...

Question 10

Consider a galvanic cell with a zinc electrode immersed in 1.0 M Zn²⁺ and a silver electrode immersed in 1.0 M Ag⁺. Zn²⁺ + 2e^- $\to$ Zn $\varepsilon$° = -0.76 V Ag⁺ + e^- $\to$ Ag $\varepsilon$° = 0.80 V Which of the electrodes is the anode?

Accepted Answer

The answer of Consider a galvanic cell with a zinc...

Question 11

Nickel is electroplated from a NiSO₄ solution.A constant current of 5.50 amp is applied by an external power supply.How long will it take to deposit 100.g of Ni? The atomic mass of Ni is 58.69.

Accepted Answer

To calculate the time required to deposit 100 g of nickel (Ni) through electroplating, we use Faraday's laws of electrolysis. The mass (m) deposited is related to the current (I), time (t), molar mass (M), and the charge number (n) (which is 2 for Ni, as it typically forms Ni^2+ ions) through the equation: $m = \frac{ItM}{nF}$, where F is Faraday's constant (96485 C/mol).Rearranging for time, we get: $t = \frac{mnF}{IM}$.Given:- m = 100 g = 0.100 kg (since the atomic mass of Ni is 58.69 g/mol, we convert the mass to kg to keep units consistent with the molar mass unit)- I = 5.50 A- M = 58.69 g/mol = 0.05869 kg/mol (to match the mass unit)- n = 2 (for Ni^2+)- F = 96485 C/molPlugging in the values: $t = \frac{0.100 \times 2 \times 96485}{5.50 \times 0.05869}$Calculating this gives a time in seconds, which can be converted to hours for comparison with the options provided.After performing the calculation, the result aligns with option A, 16.6 hours, as the correct time required to deposit 100 g of Ni through electroplating under the given conditions.

Question 12

Gold (atomic mass = 197.0)is plated from a solution of chloroauric acid,HAuCl₄;it deposits on the cathode.Calculate the time it takes to deposit 0.30 gram of gold,passing a current of 0.10 amperes.(1 faraday = 96,485 coulombs)

Accepted Answer

The answer of Gold (atomic mass = 197.0)is plated from...

Question 13

What mass of chromium could be deposited by electrolysis of an aqueous solution of Cr₂(SO₄)₃ for 145 minutes using a constant current of 11.0 amperes?

Accepted Answer

To find the mass of chromium deposited, use Faraday's laws of electrolysis. First, calculate the total charge (Q) using Q = current (I) × time (t). Then, determine the moles of electrons using Faraday's constant (F = 96485 C/mol). Chromium in Cr2(SO4)3 is in the +3 oxidation state, so 3 moles of electrons are needed to deposit 1 mole of chromium. Finally, calculate the mass using the molar mass of chromium (52 g/mol). The correct mass is approximately 17.2 g.

Question 14

What are the products of the chlor-alkali process?

Accepted Answer

The chlor-alkali process involves the electrolysis of a sodium chloride solution resulting in the production of sodium hydroxide and chlorine gas. Therefore, the correct answer is D - sodium hydroxide and chlorine.

Question 15

Which of the following used to be more precious than gold or silver,due to difficulties refining it?

Accepted Answer

Aluminum used to be more precious than gold or silver because it was difficult to refine it. In the 19th century, it was even more valuable than gold due to the challenges in its extraction and production. However, advancements in technology have made it easier to refine aluminum, and it is no longer as precious as it once was.

Question 16

Balance the following equation: Zn + As₂O₃ $\to$ AsH₃ + Zn²⁺ (acid)

Accepted Answer

The answer of Balance the following equation: Zn + As₂O₃...

Question 17

Balance the following equation: Bi(OH)₃ + SnO₂²^- $\to$ Bi + SnO₃²^- (base)

Accepted Answer

The answer of Balance the following equation: Bi(OH)₃ + SnO₂²^-...

Question 18

How many seconds would it take to deposit 18.2 g of Ag (atomic mass = 107.87)from a solution of AgNO₃ using a current of 10.00 amp?

Accepted Answer

The answer of How many seconds would it take to...

Quiz 18: Electrochemistry

Gold is produced electrochemically from an aqueous solution of Au(CN) ₂^- containing an excess of CN^-.Gold metal and oxygen gas are produced at the electrodes.How many moles of O₂ will be produced during the production of 1.00 mole of gold?

Which of the following are incorrectly paired?

Balance the following equation: Cr₂O₇²^- + I^- $\to$ Cr³⁺ + IO₃^- (acid)

If an electrolysis plant operates its electrolytic cells at a total current of 1.8 $\times$ 10⁶amp,how long will it take to produce one metric ton (one million grams) of Mg(s) from seawater containing Mg²⁺? (1 faraday = 96,485 coulombs)

Balance the following equation: MnO₄^- + Br^- $\to$ MnO₂ + BrO₃^- (base)

What mass of Ti(s) may be deposited from an aqueous TiCl₂ solution if a current of 2.50 A is applied to the solution for 365 s? ( $\varepsilon$ °_red(Ti²⁺/Ti) = -1.63 V,F = 96485 C/mol)

If a constant current of 5.0 amperes is passed through a cell containing Cr³⁺ for 1.0 hour,how many grams of Cr will plate out onto the cathode? (The atomic mass of Cr is 51.996. )

An unknown metal (M) is electrolyzed.It took 74.1 s for a current of 2.00 amp to plate 0.107 g of the metal from a solution containing M(NO₃) ₃.Identify the metal.

A solution of MnO₄²^- is electrolytically reduced to Mn³⁺.A current of 8.07 amp is passed through the solution for 15.0 minutes.What is the number of moles of Mn³⁺ produced in this process? (1 faraday = 96,485 coulombs)

Consider a galvanic cell with a zinc electrode immersed in 1.0 M Zn²⁺ and a silver electrode immersed in 1.0 M Ag⁺. Zn²⁺ + 2e^- $\to$ Zn $\varepsilon$ ° = -0.76 V Ag⁺ + e^- $\to$ Ag $\varepsilon$ ° = 0.80 V Which of the electrodes is the anode?

Nickel is electroplated from a NiSO₄ solution.A constant current of 5.50 amp is applied by an external power supply.How long will it take to deposit 100.g of Ni? The atomic mass of Ni is 58.69.

Gold (atomic mass = 197.0) is plated from a solution of chloroauric acid,HAuCl₄;it deposits on the cathode.Calculate the time it takes to deposit 0.30 gram of gold,passing a current of 0.10 amperes.(1 faraday = 96,485 coulombs)

What mass of chromium could be deposited by electrolysis of an aqueous solution of Cr₂(SO₄) ₃ for 145 minutes using a constant current of 11.0 amperes?

What are the products of the chlor-alkali process?

Which of the following used to be more precious than gold or silver,due to difficulties refining it?

Balance the following equation: Zn + As₂O₃ $\to$ AsH₃ + Zn²⁺ (acid)

Balance the following equation: Bi(OH)₃ + SnO₂²^- $\to$ Bi + SnO₃²^- (base)

How many seconds would it take to deposit 18.2 g of Ag (atomic mass = 107.87) from a solution of AgNO₃ using a current of 10.00 amp?

Quiz 18: Electrochemistry

Gold is produced electrochemically from an aqueous solution of Au(CN) 2- containing an excess of CN-.Gold metal and oxygen gas are produced at the electrodes.How many moles of O2 will be produced during the production of 1.00 mole of gold?

Which of the following are incorrectly paired?

Balance the following equation: Cr2O72- + I- →\to→ Cr3+ + IO3- (acid)

If an electrolysis plant operates its electrolytic cells at a total current of 1.8 ×\times× 106 amp,how long will it take to produce one metric ton (one million grams) of Mg(s) from seawater containing Mg2+? (1 faraday = 96,485 coulombs)

Balance the following equation: MnO4- + Br- →\to→ MnO2 + BrO3- (base)

What mass of Ti(s) may be deposited from an aqueous TiCl2 solution if a current of 2.50 A is applied to the solution for 365 s? ( ε\varepsilonε °red(Ti2+/Ti) = -1.63 V,F = 96485 C/mol)

If a constant current of 5.0 amperes is passed through a cell containing Cr3+ for 1.0 hour,how many grams of Cr will plate out onto the cathode? (The atomic mass of Cr is 51.996. )

An unknown metal (M) is electrolyzed.It took 74.1 s for a current of 2.00 amp to plate 0.107 g of the metal from a solution containing M(NO3) 3.Identify the metal.

A solution of MnO42- is electrolytically reduced to Mn3+.A current of 8.07 amp is passed through the solution for 15.0 minutes.What is the number of moles of Mn3+ produced in this process? (1 faraday = 96,485 coulombs)

Consider a galvanic cell with a zinc electrode immersed in 1.0 M Zn2+ and a silver electrode immersed in 1.0 M Ag+. Zn2+ + 2e- →\to→ Zn ε\varepsilonε ° = -0.76 V Ag+ + e- →\to→ Ag ε\varepsilonε ° = 0.80 V Which of the electrodes is the anode?

Nickel is electroplated from a NiSO4 solution.A constant current of 5.50 amp is applied by an external power supply.How long will it take to deposit 100.g of Ni? The atomic mass of Ni is 58.69.

Gold (atomic mass = 197.0) is plated from a solution of chloroauric acid,HAuCl4;it deposits on the cathode.Calculate the time it takes to deposit 0.30 gram of gold,passing a current of 0.10 amperes.(1 faraday = 96,485 coulombs)

What mass of chromium could be deposited by electrolysis of an aqueous solution of Cr2(SO4) 3 for 145 minutes using a constant current of 11.0 amperes?

What are the products of the chlor-alkali process?

Which of the following used to be more precious than gold or silver,due to difficulties refining it?

Balance the following equation: Zn + As2O3 →\to→ AsH3 + Zn2+ (acid)

Balance the following equation: Bi(OH)3 + SnO22- →\to→ Bi + SnO32- (base)

How many seconds would it take to deposit 18.2 g of Ag (atomic mass = 107.87) from a solution of AgNO3 using a current of 10.00 amp?

Gold is produced electrochemically from an aqueous solution of Au(CN) ₂^- containing an excess of CN^-.Gold metal and oxygen gas are produced at the electrodes.How many moles of O₂ will be produced during the production of 1.00 mole of gold?

Balance the following equation: Cr₂O₇²^- + I^- $\to$ Cr³⁺ + IO₃^- (acid)

If an electrolysis plant operates its electrolytic cells at a total current of 1.8 $\times$ 10⁶amp,how long will it take to produce one metric ton (one million grams) of Mg(s) from seawater containing Mg²⁺? (1 faraday = 96,485 coulombs)

Balance the following equation: MnO₄^- + Br^- $\to$ MnO₂ + BrO₃^- (base)

What mass of Ti(s) may be deposited from an aqueous TiCl₂ solution if a current of 2.50 A is applied to the solution for 365 s? ( $\varepsilon$ °_red(Ti²⁺/Ti) = -1.63 V,F = 96485 C/mol)

If a constant current of 5.0 amperes is passed through a cell containing Cr³⁺ for 1.0 hour,how many grams of Cr will plate out onto the cathode? (The atomic mass of Cr is 51.996. )

An unknown metal (M) is electrolyzed.It took 74.1 s for a current of 2.00 amp to plate 0.107 g of the metal from a solution containing M(NO₃) ₃.Identify the metal.

A solution of MnO₄²^- is electrolytically reduced to Mn³⁺.A current of 8.07 amp is passed through the solution for 15.0 minutes.What is the number of moles of Mn³⁺ produced in this process? (1 faraday = 96,485 coulombs)

Consider a galvanic cell with a zinc electrode immersed in 1.0 M Zn²⁺ and a silver electrode immersed in 1.0 M Ag⁺. Zn²⁺ + 2e^- $\to$ Zn $\varepsilon$ ° = -0.76 V Ag⁺ + e^- $\to$ Ag $\varepsilon$ ° = 0.80 V Which of the electrodes is the anode?

Nickel is electroplated from a NiSO₄ solution.A constant current of 5.50 amp is applied by an external power supply.How long will it take to deposit 100.g of Ni? The atomic mass of Ni is 58.69.

Gold (atomic mass = 197.0) is plated from a solution of chloroauric acid,HAuCl₄;it deposits on the cathode.Calculate the time it takes to deposit 0.30 gram of gold,passing a current of 0.10 amperes.(1 faraday = 96,485 coulombs)

What mass of chromium could be deposited by electrolysis of an aqueous solution of Cr₂(SO₄) ₃ for 145 minutes using a constant current of 11.0 amperes?

Balance the following equation: Zn + As₂O₃ $\to$ AsH₃ + Zn²⁺ (acid)

Balance the following equation: Bi(OH)₃ + SnO₂²^- $\to$ Bi + SnO₃²^- (base)

How many seconds would it take to deposit 18.2 g of Ag (atomic mass = 107.87) from a solution of AgNO₃ using a current of 10.00 amp?