Chemistry Multiple Choice Quiz - Electrolysis

Hydrogen is produced at the cathode during the electrolysis of dilute salt water because hydrogen ions have a stronger tendency to gain electrons (reduction) compared to sodium ions. This is based on their relative positions in the reactivity series, where hydrogen is more reactive than sodium.

Aluminum reacts with hot and concentrated alkalis, like sodium hydroxide (NaOH), to produce hydrogen gas. This reaction involves the formation of aluminate ions [Al(OH)4]- and the release of hydrogen. Other metals like sodium, iron, and copper don't show this behavior.

Dilute hydrochloric acid (HCl) and dilute nitric acid (HNO3) can be distinguished using a solution of ferrous sulfate (FeSO4). FeSO4 reacts with HNO3 to form a brown ring, while it doesn't change color with HCl.

In a metal that conducts electricity but doesn't react with dilute hydrochloric acid (HCl), free electrons are responsible for conducting electricity. This is because the metal's atoms form a metallic lattice with delocalized electrons that can easily move and carry charge.

Concentrated sulfuric acid (H2SO4) reacts with ethanol (C2H5OH) to form a gas called ethene (C2H4). Ethene decolorizes bromine water because it readily reacts with bromine and breaks its double bond. H2SO4 is not a drying agent in this case, it acts as a dehydrating agent.

The negative terminal of a battery is usually connected to the cathode in an electrolytic cell. This is because the cathode attracts positive ions, which are reduced (gaining electrons) during electrolysis.

The positive terminal of the battery is connected to the anode in an electrolytic cell. The anode attracts negative ions, which are oxidized (losing electrons) during electrolysis.

Electrolytes are substances that conduct electricity when dissolved in water, like acids, bases, and salts. In electrolytic cells, electrolytes provide the ions needed for the chemical reactions at the electrodes.

During electrolysis, the cathode is the electrode where reduction occurs. This involves the gain of electrons, leading to the formation of a new species with a lower oxidation state. In this case, a metal cation accepts electrons and is deposited as a neutral metal atom on the cathode.

The anode is the electrode where oxidation occurs during electrolysis, resulting in the loss of electrons. In this case, the anode will be made of the metal, which loses electrons to form a positively charged metal ion that dissolves into the electrolyte.

A universal indicator is a mixture of dyes that change color based on the pH of a solution. It helps identify the pH range of a solution quickly.

Froth flotation is a process used to separate sulfide ores from impurities. It involves creating a froth that selectively attaches to the desired mineral and floats to the surface.

Ethane undergoes a substitution reaction with chlorine to form chloroethane. This means that a hydrogen atom in the ethane molecule is replaced by a chlorine atom.

The process of determining the percentage of a desired component in a mixture, often used in analyzing the purity of a substance.

A chemical equation that represents the reaction involving the decomposition of lead(II,IV) oxide (Pb3O4) into lead(II) oxide (PbO) and oxygen gas (O2).

The reaction occurring at the positive electrode (anode) during the electrolysis of a dilute sodium chloride (NaCl) solution using graphite electrodes. This reaction involves the oxidation of chloride ions (Cl-) to chlorine gas (Cl2).

The reaction occurring at the positive electrode (anode) during the electrolysis of a sodium argentocyanide solution using silver electrodes. This reaction involves the oxidation of silver ions (Ag+) from the complex ion to form solid silver metal (Ag).

A chemical reaction in the laboratory where methane (CH4) is produced from the reaction of a suitable reactant with a specific reagent.

A chemical reaction in the laboratory where ethanol (C2H5OH) is produced from the reaction of a suitable reactant with a specific reagent.

A chemical reaction in the laboratory where ethyne (C2H2) is produced from the reaction of a suitable reactant with a specific reagent.

The ability of two or more organic compounds with the same molecular formula to have different arrangements of atoms within the molecule, leading to different chemical and physical properties. For example, butane (C4H10) can exist as n-butane and isobutane, which differ in their branching.

A chemical property of sulphuric acid indicating its ability to act as a dehydrating agent, removing water molecules from hydrated compounds like blue vitriol (CuSO4.5H2O) to form anhydrous copper sulphate (CuSO4).

A property of concentrated sulphuric acid reflecting its ability to act as a strong oxidizing agent, causing the oxidation of sodium nitrate (NaNO3) to nitric acid (HNO3) while itself getting reduced.

To distinguish between copper(II) oxide (CuO) and manganese dioxide (MnO2), add dilute hydrochloric acid (HCl) to both. CuO reacts with HCl to form a blue-green solution of copper chloride, while MnO2 does not react.

Concentrated sulphuric acid is more viscous and heavier than dilute sulphuric acid. Add a small amount of sugar to a test tube containing both forms of acid - the sugar will char in the presence of concentrated acid, showing its strong dehydrating property.

Sodium carbonate (Na2CO3) reacts with dilute hydrochloric acid (HCl) to produce brisk effervescence of carbon dioxide, while sodium sulphite (Na2SO3) reacts with HCl to liberate sulphur dioxide, which has a pungent smell.

The Ostwald process involves three main steps: first, ammonia (NH3) is oxidized with air to form nitrogen monoxide (NO), which is then further oxidized to nitrogen dioxide (NO2), finally, NO2 is dissolved in water to form nitric acid (HNO3).

Addition of excess ammonia (NH3) to chlorine (Cl2) results in a reaction that produces nitrogen gas (N2) and ammonium chloride (NH4Cl).

The reaction of ethyne (C2H2) with chlorine (Cl2) in carbon tetrachloride (CCl4) leads to the formation of 1,1,2,2-tetrachloroethane (C2H2Cl4).

Glycerol is a non-electrolyte, meaning it does not conduct electricity when dissolved in water. This is because glycerol does not dissociate into ions in solution.

C4H6 is an alkyne due to the presence of a triple bond between two carbon atoms. Alkyne formulas follow the general formula CnH2n-2.

The atomic number of an element is the number of protons in its nucleus. The element with atomic number 13 is Aluminum (Al). Aluminum forms a hydride, AlH3, with three hydrogen atoms per molecule.

Isotopes of the same element have the same number of protons but differ in the number of neutrons. The position of an element in the periodic table is determined by its proton number. As C-13 and C-12 have the same number of protons, they occupy the same position on the periodic table.

Calcium forms a white precipitate with NaOH solution because calcium hydroxide (Ca(OH)2) is insoluble in water. However, calcium hydroxide is soluble in ammonium hydroxide (NH4OH) solution.

A highly stable element has a full outermost electron shell, achieving a noble gas configuration. The configuration 2,8,8,1 has one electron in its outermost shell, making it highly reactive. The configuration 2,8,8, is most stable and non-reactive as it has a complete outermost shell.

Halogens are located in group 17 of the periodic table and have 7 electrons in their outermost shell. They gain one electron to achieve a stable octet configuration, resulting in the formation of uni-negative ions.

The ratio of atoms in a given volume of gas is proportional to the number of moles present. 2.24 L of Nitrogen gas at STP (standard temperature and pressure) is equal to one mole of Nitrogen, containing 6.022 x 10^23 molecules of Nitrogen. 0.4g of Helium at STP is equal to 0.1 moles, corresponding to 6.022 x 10^22 Helium atoms. The ratio of Nitrogen atoms to Helium atoms is 10:1.