JAMB UTME - Chemistry - 2022

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Carbon dioxide (CO2) has a linear molecular geometry, with two oxygen atoms bonded to the central carbon atom. Each bond between carbon and oxygen is a double bond, consisting of two pairs of electrons shared between the atoms. Therefore, there are two bonding pairs in each of the carbon-oxygen double bonds, giving a total of four bonding pairs in CO2. The answer is 4.

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The IUPAC nomenclature of the structure is "2-chloro-2-methylbutane". The name is derived by first identifying the longest carbon chain, which in this case contains four carbon atoms (butane). The carbon chain is numbered from one end to the other, giving the substituents the lowest possible numbers. Starting from either end, we can see that the first carbon atom has a chlorine atom attached to it, which is represented by the prefix "chloro-". Moving along the chain, the second carbon atom has a methyl group attached to it, which is represented by the prefix "methyl-". Since the substituents are in the second position from each other, we use the prefix "di-" to indicate two substituents in this position. Finally, we use the suffix "-ane" to indicate that the molecule is an alkane. Therefore, the correct name for this molecule is "2-chloro-2-methylbutane".

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The highest equilibrium yield of N2O4 would be produced at low temperature and low pressure. In a chemical reaction, the position of the equilibrium can be influenced by changing the temperature or pressure. A decrease in temperature or an increase in pressure favors the side of the reaction with the fewer moles of gas (in this case, N2O4). This means that, if the temperature is low and the pressure is low, there will be more N2O4 at equilibrium, as the reaction will shift to the right to counteract the reduction in the concentration of N2O4. So, low temperature and low pressure would produce the highest equilibrium yield of N2O4.

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Mixing aqueous solutions of barium hydroxide and sodium tetraoxocarbonate (IV) would result in a chemical reaction that produces a white precipitate of barium tetraoxocarbonate (IV). The balanced chemical equation for this reaction is: Ba(OH)2(aq) + Na2CO3(aq) → BaCO3(s) + 2NaOH(aq) In the above equation, the barium hydroxide (Ba(OH)2) reacts with sodium tetraoxocarbonate (IV) (Na2CO3) to form barium tetraoxocarbonate (IV) (BaCO3), which is a white precipitate, and sodium hydroxide (NaOH). Therefore, the correct option is 4) Barium tetraoxocarbonate.

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The electrochemical series is a list of metals and ions arranged in order of their decreasing tendency to lose or gain electrons, and thus, their ability to act as reducing or oxidizing agents. The higher the position of a metal or ion in the electrochemical series, the greater its tendency to lose electrons and undergo oxidation, while the lower its position, the greater its tendency to gain electrons and undergo reduction. In an electrolytic cell, the cathode is the electrode where reduction occurs, meaning that cations (positively charged ions) are attracted and gain electrons to form neutral atoms or molecules. Based on the electrochemical series, the ion with the higher position in the series will have a greater tendency to gain electrons and be discharged at the cathode, while the ion with the lower position will have a lower tendency and may not be discharged at all. Among the given options, the electrochemical series order is: Cu2+ > Sn2+ > Fe2+ > Zn2+ Therefore, Cu2+ has the highest tendency to be discharged at the cathode and undergo reduction, while Zn2+ has the lowest tendency. So, in an electrolytic cell, Cu2+ will be discharged at the cathode, while Zn2+ may not be discharged at all, depending on the conditions of the cell.

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In the above reaction, zinc (Zn) reacts with hydrochloric acid (HCl) to form zinc chloride (ZnCl2) and hydrogen gas (H2). The chemical equation for the reaction is: Zn + 2HCl → ZnCl2 + H2 During the reaction, zinc atoms lose two electrons each and get oxidized to form positively charged zinc ions (Zn2+), as they react with the hydrogen ions (H+) from the hydrochloric acid to form zinc chloride. The hydrogen ions, on the other hand, gain an electron each and get reduced to form hydrogen gas molecules (H2). Therefore, in the given reaction, zinc is getting oxidized, as it loses electrons and forms a positively charged ion. Hence, the correct option is "oxidized."

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The metal that can liberate hydrogen gas from steam is iron. The metal activity series is a list of metals in order of their reactivity, with the most reactive metals at the top and the least reactive metals at the bottom. When a metal is placed in a solution of steam (water vapor), the metal will react with the steam if it is more reactive than hydrogen. In this case, iron is more reactive than hydrogen, so it can displace hydrogen from the steam to form hydrogen gas. This reaction can be represented by the equation: Fe + H2O (steam) → FeO (iron oxide) + H2 (hydrogen gas) So, when steam is passed over iron, hydrogen gas is liberated and iron oxide is formed.

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The active component of baking powder is sodium bicarbonate (NaHCO3). It is responsible for the leavening or rising of baked goods by releasing carbon dioxide gas when it reacts with an acid. Other ingredients in baking powder, such as monocalcium phosphate and sodium aluminum sulfate, provide the acid component for the reaction to occur. Magnesium sulfate (MgSO4) and calcium sulfate (CaSO4) are not typically used in baking powder, and sodium chloride (NaCl) is simply table salt and not an active ingredient in leavening.

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Given:

• Initial pressure, 𝑃1=10P1​=10 atmospheres
• Initial volume, 𝑉1=30 cm3V1​=30cm3
• Final volume, 𝑉2=20 dm3V2​=20dm3

First, convert all volumes to the same units. Since 1 dm3dm3 is 1000 cm3cm3:

𝑉2=20 dm3=20×1000 cm3=20000 cm3V2​=20dm3=20×1000cm3=20000cm3

Now, using Boyle's Law:

𝑃1𝑉1=𝑃2𝑉2P1​V1​=P2​V2​

Substitute the known values into the equation:

10×30=𝑃2×2000010×30=P2​×20000

300=𝑃2×20000300=P2​×20000

Solve for 𝑃2P2​:

𝑃2=30020000P2​=20000300​

𝑃2=0.015 atmospheresP2​=0.015atmospheres

Therefore, the new pressure if the temperature is kept constant is:

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The correct answer is: "melting does not break the metallic bond but boiling does." The metallic bond is the force of attraction between metal atoms, which holds them together to form a solid. When a metal is heated, its temperature increases, and at a certain point, the energy provided by the heat is enough to overcome the metallic bond and cause the metal to melt. However, even in the liquid state, the metallic bond remains intact, which is why metals have a very high melting point. On the other hand, when the temperature is further increased, the energy provided by the heat becomes enough to break the metallic bond, and the metal atoms become completely detached from one another. This results in the metal boiling and turning into a gas. Because the metallic bond is much stronger than other types of intermolecular forces, such as van der Waals forces, it requires a lot of energy to break, resulting in a large temperature interval between the melting point and boiling point of metal.

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An acidic oxide is an oxide that reacts with water to form an acidic solution. Non-metals have a greater tendency to form acidic oxides than metals. Therefore, among the given options, the non-metal that does not form an acidic oxide with oxygen would be the one that does not react with water to form an acidic solution. Out of the given options, chlorine is the non-metal that does not form acidic oxides with oxygen. Chlorine reacts with oxygen to form a number of oxides such as chlorine monoxide (Cl2O), chlorine dioxide (ClO2), and chlorine trioxide (ClO3), but none of these oxides react with water to form an acidic solution. Instead, they react with water to form oxyacids or oxoacids such as hypochlorous acid (HClO), chlorous acid (HClO2), and chloric acid (HClO3), which are stronger acids than the oxides. Therefore, the correct answer is chlorine.

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The organic compound with a fishy smell is most likely to have the general formula RNH2, which represents a primary amine. Amines are organic compounds that contain a nitrogen atom bonded to one or more carbon atoms. Primary amines have one alkyl or aryl group and two hydrogen atoms bonded to the nitrogen atom. Some primary amines have a fishy smell, which is caused by the presence of volatile amines. These amines are small molecules that can easily evaporate and have a strong odor, similar to that of fish. Examples of compounds that have a fishy smell include trimethylamine, which is found in fish, and butylamine, which is used in the production of rubber and pharmaceuticals. In summary, the organic compound with a fishy smell is likely to have the general formula RNH2, which represents a primary amine.

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The function of sulphur during the vulcanization of rubber is to form chains which bind rubber molecules together.

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The oxidizing and reducing properties of a substance depend on its ability to gain or lose electrons. A substance that can gain electrons acts as an oxidizing agent, while a substance that can lose electrons acts as a reducing agent. Among the given options, both Cl2 (chlorine gas) and SO2 (sulfur dioxide) can act as both oxidizing and reducing agents depending on the reaction conditions. - Cl2 can act as an oxidizing agent when it gains electrons to form Cl- ions, and it can act as a reducing agent when it loses electrons to form Cl+ ions. For example, in the reaction Cl2 + 2KBr → 2KCl + Br2, chlorine gas is acting as an oxidizing agent since it is gaining electrons from bromide ions to form bromine gas. However, in the reaction 2Cl- + Cl2 → 2Cl2-, chlorine gas is acting as a reducing agent since it is losing electrons to form chloride ions. - SO2 can act as an oxidizing agent when it gains electrons to form sulfite ions (SO32-), and it can act as a reducing agent when it loses electrons to form sulfur trioxide (SO3). For example, in the reaction SO2 + 2H2S → 3S + 2H2O, sulfur dioxide is acting as a reducing agent since it is losing electrons to form elemental sulfur. However, in the reaction 2SO32- + O2 → 2SO42-, sulfur dioxide is acting as an oxidizing agent since it is gaining electrons to form sulfate ions. H2S (hydrogen sulfide) and NH3 (ammonia) are not likely to act as both oxidizing and reducing agents under normal conditions. H2S tends to act as a reducing agent by donating electrons to oxidizing agents, while NH3 tends to act as a reducing agent by donating electrons to oxidizing agents or as a base by accepting protons.

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When heat is absorbed during a chemical reaction, the reaction is said to be endothermic. Endothermic reactions are characterized by the absorption of heat energy from the surroundings. In other words, the reactants absorb energy from the environment, usually in the form of heat, to form the products. As a result, the temperature of the surroundings decreases, and the reaction feels cold to the touch. Endothermic reactions can be found in many natural processes, such as photosynthesis, melting of ice, and the evaporation of liquids. These processes require energy to occur, and they absorb heat from the surroundings to power the reaction.

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Graphite is the option that conducts electricity.

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Wrought iron is a type of iron that is very malleable and ductile, meaning it can be easily shaped and formed into various objects. It is obtained by heating cast iron in a furnace with haematite, also known as iron(III) oxide. When cast iron is heated with haematite in a furnace, a chemical reaction takes place where the haematite reacts with the carbon in the cast iron to produce carbon dioxide gas. This reaction also produces molten iron, which is then further heated to remove any impurities like sulfur and phosphorus. This molten iron is then poured into molds to form ingots of wrought iron. Therefore, haematite is essential in the process of obtaining wrought iron from cast iron.

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The shape of a molecule of CCl4 is tetrahedral.

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The statement that is TRUE of the complete hydrolysis of a glyceride by sodium hydroxide is: - 3 moles of NaOH are required for each mole of glyceride. During the hydrolysis of a glyceride (a triglyceride), the ester bonds between the fatty acid chains and glycerol are broken by the action of a strong base like sodium hydroxide. This results in the formation of glycerol and the corresponding salts of fatty acids, which are commonly known as "soaps." The reaction can be represented by the following equation: Triglyceride + 3 NaOH → 3 soap + glycerol As per the equation, 3 moles of NaOH are required to hydrolyze one mole of glyceride, and 3 moles of soap and one mole of glycerol are produced. The use of concentrated sulfuric acid (H2SO4) is not essential for the completion of the reaction, but it can be used as a catalyst to speed up the reaction.

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In the extraction of iron, hot air is introduced into the blast furnace through tuyeres. Tuyeres are nozzles that are located at the bottom of the blast furnace, and they are used to blow hot air into the furnace. The hot air helps to burn the coke (a fuel made from coal) which provides the heat needed to melt the iron ore. The air also helps to remove the waste gases that are produced during the reaction, allowing the iron to be extracted more efficiently.

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The chemical widely used as a fertilizer is nitrochalk. Nitrochalk is a type of fertilizer that contains a mixture of ammonium nitrate and calcium carbonate. Ammonium nitrate provides the necessary nitrogen for plant growth, while calcium carbonate helps to balance the soil's pH level. This combination of nutrients helps to promote healthy plant growth and increase crop yields. Nitrochalk is commonly used in agriculture and gardening to fertilize crops such as corn, wheat, and soybeans, as well as fruits and vegetables.

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We can use the ideal gas law to solve this problem, which states that PV = nRT, where P is pressure, V is volume, n is the number of moles of gas, R is the gas constant, and T is temperature in kelvin. If the volume and pressure are both increased by a factor of 4, then the new volume V' and new pressure P' are given by: V' = 4V P' = 4P Substituting these values into the ideal gas law, we get: (4P)(4V) = nR(T') Simplifying this equation, we get: 16PV = nRT' Dividing both sides by PV, we get: 16 = nRT' / PV Since n, R, and P are constant, we can simplify this to: 16 = T' / T Solving for T', we get: T' = 16T Therefore, the new temperature is 16 times the original temperature. Substituting T = 298 K, we get: T' = 16 x 298 K = 4768 K So the correct answer is 4768.0K.

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The balanced chemical equation shows that 2 moles of hydrogen gas react with 1 mole of oxygen gas to produce 2 moles of water vapor. Therefore, the stoichiometric ratio of hydrogen to oxygen is 2:1. In this problem, there are 50cm3 of hydrogen gas and 75cm3 of oxygen gas. Since the gases are at the same temperature and pressure, their volumes are directly proportional to the number of moles of gas present. Using the stoichiometric ratio, we can calculate that the amount of oxygen gas required to react completely with 50cm3 of hydrogen gas is (1/2) * 50cm3 = 25cm3. Since there are 75cm3 of oxygen gas present, there must be (75cm3 - 25cm3) = 50cm3 of unreacted oxygen gas remaining. Therefore, the volume of unreacted oxygen gas is 50cm3. Answer: 50cm3

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The substance that is not a homogeneous mixture is flood water. Flood water is typically a mixture of various substances, such as sediment, dirt, debris, and organic matter, that have been carried along by the water. As such, flood water is usually a heterogeneous mixture, meaning that it does not have a uniform composition throughout. In contrast, filtered sea water, soft drinks, and writing ink are all examples of homogeneous mixtures, where the components are evenly distributed and the mixture has a uniform composition throughout.

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The method employed in the preparation of salts will depend on the composition of the salt. Different salts have different chemical properties, and the method used to prepare them will depend on these properties. For example, some salts can be easily dissolved in water, while others are not very soluble and may require the use of a different solvent or special conditions to dissolve. The dissociating ability, stability to heat, and precipitating ability of the salt may also play a role in determining the preparation method, but the most important factor is the composition of the salt.

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The most suitable catalyst for the given reaction is vanadium(V)oxide (V2O5). Vanadium(V)oxide is a commonly used catalyst for the oxidation of sulfur dioxide (SO2) to sulfur trioxide (SO3). The reaction is an exothermic reaction, and it occurs at high temperatures (around 450-500°C) in the presence of a catalyst. V2O5 is an effective catalyst for this reaction because it has a high surface area and can provide active sites for the reaction to occur. The vanadium ions in the V2O5 catalyst undergo redox reactions with the sulfur dioxide and oxygen molecules, which promotes the formation of sulfur trioxide. Chromium(VI)oxide and iron(III)oxide are not suitable catalysts for this reaction because they are not effective at promoting the oxidation of sulfur dioxide to sulfur trioxide. Copper(I)oxide can be used as a catalyst for the reaction, but it is not as effective as vanadium(V)oxide.

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Chlorine is not a common bleaching agent for wet litmus paper, wet pawpaw leaf, and most wet fabric dyes. It is commonly used as a bleaching agent for printer's ink.

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The liquid is most likely to be option number 4: CH3OHCHOH2OH, which is also known as glycerol or glycerin. Glycerol has a high boiling point of 290°C, which is much higher than the boiling points of the other options. It is also a viscous liquid, which means it is thick and sticky. Glycerol is non-toxic, and it is often used in food, pharmaceuticals, and cosmetics. Furthermore, glycerol is miscible with water, which means that it can be easily mixed with water to form a homogeneous solution. It is also hygroscopic, which means that it can absorb water from the air. These properties make glycerol a useful substance in many applications, such as as a moisturizer in skincare products or as a humectant in food processing.

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The sub-atomic particles located in the nucleus of an atom are neutron and proton. The nucleus is the dense core of an atom that contains most of its mass. Protons are positively charged particles found in the nucleus, and they determine the atomic number of the element. Neutrons are neutral particles found in the nucleus, and they help stabilize the nucleus by balancing the repulsive forces between the positively charged protons. Electrons, on the other hand, are negatively charged particles that are located outside the nucleus in energy levels or shells. They are attracted to the positively charged nucleus by electrostatic forces and are involved in chemical bonding between atoms. The number of protons in the nucleus determines the identity of the element, while the number of neutrons determines its isotopes. Isotopes of an element have the same number of protons but different numbers of neutrons in the nucleus. In summary, the two sub-atomic particles located in the nucleus of an atom are neutron and proton.

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According to Charles's Law, the ratio of the initial and final temperatures is equal to the ratio of the initial and final volumes at constant pressure. The ratio of the final volume to the initial volume is: Vf / Vi = 7.5 dm3 / 2.5 dm3 = 3 Therefore, the ratio of the final temperature to the initial temperature is also 3: Tf / Ti = Vf / Vi = 3 So the answer is 3:1.

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