Free Electrochemistry MCQs with Answers

• A. Reacts
• B. Decomposes
• C. Disappears
• D. Ionizes
• E. Never ionizes

Explanation: They completely ionizes into the solution. So option D is correct.

• A. Metallurgy of Na
• B. Metallurgy of Mg
• C. Metallurgy of Al
• D. Metallurgy of Fe
• E. Metallurgy of ca

Explanation: The Down's cell is used for the metallurgy of sodium (Na).In the metallurgy of sodium, the Down's cell is an electrolytic cell that is…

• A. Acid-base reaction
• B. Redox reaction
• C. Nuclear reaction
• D. Neutralization reaction

Explanation: An electrochemical cell is based on a redox reaction. Redox reactions involve the transfer of electrons between species.

• A. OF2
• B. Na2O2
• C. KO2
• D. Cl2O7

Explanation: In KO2 (potassium superoxide), oxygen shows a fractional oxidation number. The oxidation number of oxygen in most compounds is -2.

• A. The change is reduction, because there has been a gain of electrons
• B. The change is oxidation, because there has been a loss of electrons
• C. The change is reduction, because there has been a loss of electrons
• D. The change is oxidation, because there has been a gain of electrons

Explanation: In the formation of an ionic bond between magnesium and chlorine, magnesium atoms lose two electrons to achieve a stable electronic…

• A. Beryllium
• B. Chlorine
• C. Nitrogen
• D. Bromine

Explanation: In periodic table groups I-A, II-A members and fluorine show only one oxidation state in all of their compounds.

• A. Less than the anode
• B. More than the anode
• C. Same as that of anode
• D. Zero

Explanation: In electrochemistry, the electrode potential is the electromotive force of a galvanic cell built from a standard reference electrode and…

• A. Reduce the compound.
• B. Oxidize the compound.
• C. Electrolyze the compound.
• D. Neither reduce nor oxidize the compound.

Explanation: The stronger the reduction potential,the easier it is for the element to gain electrons and show reduction.Diagram:

• A. It is the electrode potential determined at room temperature and pressure.
• B. It is the electrode potential determined under standard conditions using standard hydrogen electrode as the other electrode
• C. It is the electrode potential of an element and its solution compared to a standard value.
• D. It is the potential which is measured when the two half cells are connected together.

Explanation: The correct option B describes the standard electrode potential accurately.

• A. Negative
• B. positive
• C. zero
• D. +/-1

Explanation: In a free state, an element exists in its elemental form, meaning it consists of individual atoms of that element.

• A. Electrochemistry
• B. Thermochemistry
• C. Stereochemistry
• D. Biochemistry

Explanation: Electrochemistry is the branch of chemistry, which deals with the inter-conversion of electrical energy and chemical energy.

• A. He
• B. Li
• C. Zn
• D. N

Explanation: Lithium is an alkali metal, and alkali metals have very low ionization potentials due to their single valence electron and large atomic…

• A. 0
• B. +1
• C. -1
• D. -2

Explanation: Oxidation number of an element in free state is 0. So, C12 has oxidation number zero.

• A. Barium ion
• B. Calcium ion
• C. Magnesium ion
• D. Aluminum ion

Explanation: As we go down the electrochemical series , the reduction potential increases.

• A. Hydrogen and copper
• B. Methane and oxygen
• C. Hydrogen and oxygen
• D. Nitrogen and oxygen
• E. Hydrogen and zinc

Explanation: Hydrogen and oxygen: This is the reaction in a hydrogen fuel cell, where hydrogen (H₂) reacts with oxygen (O₂) to produce electricity…

• A. 0
• B. +1
• C. -7
• D. +7

Explanation: In KMnO₄, Mn has an oxidation number of +7. This is determined by balancing the oxidation states of the other elements (K and O) in the…

• A. Split the reaction into two half reactions.
• B. Assign an oxidation number to all the atoms involved in the equation.
• C. Identify the element changing oxidation number
• D. Equalize the number of electrons lost and gained

Explanation: Option A is correct. That step belongs to the ion-electron (half-reaction) method, not the oxidation number method.In the oxidation number…

• A. Reduction occurs at cathode
• B. Oxidation occurs at anode
• C. Alternating current source is connected to electrodes
• D. Electrochemical reaction takes place

Explanation: This is an Incorrect feature of an electrolytic cell because electrolytic cells use direct current (DC), not alternating current (AC).

• A. Decomposition
• B. Dissociation
• C. Oxidation
• D. Reduction

Explanation: A substance gains electrons, decreasing its oxidation state. Often involves losing oxygen or gaining hydrogen.In an electrochemical cell…

• A. Electrolytic cell
• B. Photovoltaic cell
• C. None of these
• D. Voltaic cell

Explanation: This option is correct. A photovoltaic (PV) cell, or solar cell, is a device that converts light energy directly into electricity through…