A spontaneous thermodynamic destruction metal as a result of exposure to chemical and electrochemical environment

Задание #133

Вопрос : The process of redox decomposition of an ionic compounds by passing electricity through molten or aqueous solutions of ionic compounds is called:

Electrolysis

2) oxidation

3) dissociation

4) hydrolysis

5) corrosion

Задание #134

Вопрос : With which metal does oxygen combine to form rust?

1) Copper

2) Silver

3) Platinum

Iron

5) Gold

Задание #135

Вопрос : Which is the strongest acid in the following?

1) HClO₃

2) H₂SO₄

HCl

4) HClO₄

5) H₂SO₃

Задание #136

Вопрос : How long will it take 1.0 kg of gold (Au) to late from a solution of Au³⁺ with a current of 150 A?

1) 1 hours 35 minutes

2) 54.4 minutes

3) 2 days

4) 136 hours

Hours 43 minutes

Задание #137

Вопрос : Select a typical oxidizing agent:

1) KMnO₄

2) СО

3) С

4) iron (II) compounds

5) Н₂

Задание #138

Вопрос : The reaction of the salt with water, whereby the salt is dissociated and decomposed to form a weak electrolyte (weak acid or weak base) is called ...

1) Electrolysis

2) Dissociation

3) Osmosis

Hydrolysis

5) Corrosion

Задание #139

Вопрос : In which of the following compounds, nitrogen exhibits highest oxidation state?

1) N₂O 2) NH₃ 3) HNO₂ 4) N₂ 5) HNO₃

Задание #140

Вопрос : In the common dry cell, the zinc atoms are:

1) precipitates at the cathode

2) oxidized at the cathode

Oxidized at the anode

4) reduced at the cathode

5) reduced at the anode

Задание #141

Вопрос : Which among the following is a set of transition elements?

1) Pt, Cd, As

Zr, Au, Ni

3) Sn, Bi, Mg

4) K, Mg, Fe

5) Hg, Pb, Ca

Задание #142

Вопрос : Select the oxidation process:

Задание #143

Вопрос : Which of the following metal ions will be discharge in first at electrode?

1) Al³⁺ (E° = -1,66V)

2) Cu²⁺ (E° = +0,34V)

3) H⁺ (E° = 0V)

4) Ag⁺ (E° = +0,80V)

5) Fe²⁺ (E° = -0,44V)

Задание #144

Вопрос : What kind of water is obtained by passing the natural water through a system of cation and anion exchangers:

1) mineral water

2) hardness

3) soft water

4) distilled water

5) moderately hardness water

Задание #145

Вопрос : An equivalent weight of oxidizer KMnO₄ in a strong acidic medium is equal ... (g/mol):

1) 52,6

2) 158

3) 25,02

4) 79

5) 31,6

Задание #146

Вопрос : Which metal is extracted from Bauxite?

1) Gold

2) Aluminum

3) Tungsten

4) Arsenic

5) Iron

Задание #147

Вопрос :In an electrolytic cell:

1) potential energy decreases

2) kinetic energy decreases

3) potential energy changes into electrical energy

4) electrical energy changes into chemical energy

5) chemical energy changes into electrical energy

Задание #148

Вопрос : An equivalent weight of oxidizer KMnO₄ in a basic medium is equal ... (g/mol):

1) 79 2) 25,02 3) 158 4) 31,6 5) 52,6

Задание #149

Вопрос : Brass is ...

1) A Compound

2) An Alloy

3) A Mixture

4) A Substance

5) An Element

Задание #150

Вопрос : ………………. among the following contain partially filled d - subshell and does not show variable oxidation states.

1) Cd

2) La

3) Hg

4) Cr

5) Mn

Задание #151

Вопрос : Medium reactivity metals are obtained from their oxides by ...

1) Roasting

2) Reduction

3) Heating

4) Electrolytic Separation

5) Oxidation

Задание #152

Вопрос : Which among the following is not true for electrochemical cell?

1) It needs a porous partition

2) It consists of generally two electrolytes

3) Anode acquires negative charge

4) Cathode acquires positive charge

It consists of a battery

Задание #153

Вопрос : Which metals acts as a protector for the iron and steel constructions?

1) Zn, Mg 2) Sn, Pb 3) Cd, Na 4) Cu, Mg 5) Ni, Zn

Задание #154

Вопрос : The process of reduction of ores involving heating and melting with carbon is known as:

1) Thermite process

2) Roasting

3) Pyrolysis

4) Smelting

5) Zone refining

Задание #155

Вопрос : Calculate the electrode potential at an gold electrode, dipped in a 0,001М aqueous solution of gold salt at 25°C :

1) +1,481V 2) -1,45V 3) +1,441V 4) +1,557V 5) +1,559V

Задание #156

Вопрос : German silver is an alloy of zinc and:

1) Fe and Ni

2) Cu and Ni

3) Sn and Ni

4) Al and Fe

5) Cu and Fe

Задание #157

Вопрос : Which of the following metal ions, as Al³⁺, Na⁺, Mg²⁺, Ag⁺, will be discharged in first at electrode during molten electrolysis?

1) Na⁺, Ag⁺, Al³⁺, Mg²⁺

2) Al³⁺, Na⁺, Mg²⁺, Ag⁺

3) Ag⁺, Al³⁺, Mg²⁺, Na⁺,

4) Ag⁺, Na⁺, Mg²⁺, Al³⁺

5) Mg²⁺, Al³⁺, Na⁺, Ag⁺

Задание #158

Вопрос : Hot concentrated sulfuric acid (H₂SO₄) acts as moderately strong oxidising agent. It oxidises both metals and nometals. Which of the following element is oxidised by conc. H₂SO₄into gaseous products?

1) Cu 2) Zn 3) S 4) NaCl 5) C

Задание #159

Вопрос : The chemical equivalent of the metal is 19.3. When 3A of electric current is passed for 50 min. What will be the amount of metal deposited from an electrolyte?

1) 3.6 g 2) 0.9 g 3) 4.2 g 4) 0.03 g 5) 1.8 g

Задание #160

Вопрос : In the electrochemical series metals are arranged ...

1) in the order of decreasing the electrode potential

2) depending on the resistance to oxidation by oxygen

3) depending on the resistance to oxidation by strong acids

4) in the order of weakening metal solubility in water

5) in the order of increasing the electrode potential

Задание #161

Вопрос : What is the oxidation state of the central metal atom in the complex [Cu(NH₃)₄]SO₄ :

1) 0 2) +4 3) +3 4) +2 5) -2

Задание #162

Вопрос : What will be the electrode potential at an aluminium electrode, dipped in a 0,001М AlCl₃ aqueous solution at 25°C :

1) -1,601V 2) -1,84V 3) -1,719V 4) -1,54V 5) -1,64V

Задание #163

Вопрос : Which metal will serve as the cathode for iron?

1) Cu, Ni 2) Zn, Mg 3) Zn, Al 4) Cd, Mg 5) Ni, Zn

Задание #164

Вопрос : Often to prevent corrosion, metals are galvanized by covering them with a layer of ...

1) Lead 2) Copper 3) Zinc 4) Tin 5) Sodium

Задание #165

Вопрос : What is the oxidation state (OS) of the central metal atom and the coordination number (CN) in the complex Na₃[Co(H₂O)₂Cl₂PO₄] :

1) OS = -2; CN = 5

2) OS = +3; CN = 9

3) OS = +1; CN = 4

4) OS = +5; CN = 9

5) OS = +2; CN = 5

Задание #166

Вопрос : Water hardness is characterized by the presence of calcium and magnesium ions, called ...

1) total

2) temparary hardness

3) permanent hardness

Carbonate

5) technical

Задание #167

Вопрос : What is the sign of ΔG for a galvanic cell?

1) 1

Negative

3) Zero

4) Either negative or positive

5) Positive

Задание #168

Вопрос : Bronze is an alloy of ...

1) Zink, Iron and Carbon

Copper and Tin

3) Barium, Zinc and Iron

4) Copper and Zinc

5) Lead and Copper

Задание #169

Вопрос : This type, of corrosion occurs due to direct chemical attack of environment or atmospheric gases like oxygen halogens, hydrogen sulphide, sulphurdioxide, nitrogen or anhydrous inorganic liquid with metal surfaces in immediate proximity. What is the corrosion type?

Cavitation corrosion

2) galvanic corrosion

3) chemical corrosion

4) gas corrosion

5) liquid corrosion

Задание #170

Вопрос : Of four different laboratory solutions, the solution with the highest acidity has a pH of:

1) 2 2) 9 3) 11 4) 3 5) 5