JAMB UTME - Chemistry - 2022
Question 2 Report
An organic compound which liberate carbon(iv)oxide from trioxocarbonate(iv) solution is likely to be?
Answer Details
The organic compound that liberates carbon(iv)oxide from trioxocarbonate(iv) solution is CH3COOH (acetic acid).
When acetic acid is added to a solution of trioxocarbonate(iv) (carbonate) it reacts to form carbon(iv)oxide gas, water and a salt. The balanced chemical equation for the reaction is:
2CH3COOH + Na2CO3 → CO2 + 2H2O + 2NaCH3COO
The carbon(iv)oxide gas is released as bubbles, causing the solution to fizz. Therefore, CH3COOH is the organic compound that liberates carbon(iv)oxide from trioxocarbonate(iv) solution.
Question 3 Report
Which of the following is stable to heat
Answer Details
Out of the given options, K2CO3 is stable to heat.
Question 4 Report
Copper (II) tetraoxosulphate (IV) is widely used as
Answer Details
Copper (II) tetraoxosulphate (IV), also known as copper sulfate or CuSO4, is widely used as a fungicide and a disinfectant.
As a fungicide, copper sulfate is effective in controlling fungal diseases in plants, including mildew, leaf spots, and blights. It is also used as a fungicide in swimming pools to prevent the growth of algae.
As a disinfectant, copper sulfate is effective in killing bacteria and viruses. It is used in a variety of applications, including in the production of animal feed, as a preservative for wood, and in water treatment to kill bacteria and algae.
While copper sulfate has been used as a fertilizer in the past, its use in this capacity has largely been replaced by other compounds. It is not commonly used as a purifier.
Question 5 Report
\(\mathrm{N_2O_4}\) ? \(2\mathrm{NO_2}\) (? = -ve)
From the reaction above, which of these conditions would produce the highest equilibrium yield for \(\mathrm{N_2O_4}\)?
Answer Details
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.
Question 6 Report
\(H^+ + OH^- \rightarrow H_2O\)
The equation above illustrates
Question 7 Report
In the extraction of iron, hot air is introduced into the blast furnace through?
Answer Details
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.
Question 8 Report
Complete dehydrogenation of ethyne yields
Question 9 Report
How many neutrons are present in atom with mass number and atomic number 37 and 17 respectively?
Answer Details
The atomic number of an atom represents the number of protons in the nucleus of the atom. Since the atomic number given is 17, it means that there are 17 protons in the nucleus.
The mass number of an atom represents the total number of protons and neutrons present in the nucleus. Therefore, if the mass number is given as 37, it means that the total number of protons and neutrons in the nucleus is 37.
To determine the number of neutrons in the nucleus, we can subtract the atomic number (which represents the number of protons) from the mass number (which represents the total number of protons and neutrons).
Thus, the number of neutrons in the atom with a mass number of 37 and an atomic number of 17 is:
Number of neutrons = Mass number - Atomic number
= 37 - 17
= 20
Therefore, the answer is 20.
Question 10 Report
2-methylprop-1-ene is a structural isomer of?
Question 11 Report
An organic compound which decolorizes bromine water is likely to be?
Answer Details
Question 12 Report
A chemical widely used as a fertilizer is?
Answer Details
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.
Question 13 Report
An organic functional group which can likely decolorize ammoniacal silver nitrate is?
Answer Details
The organic functional group that can likely decolorize ammoniacal silver nitrate is an alkyne.
When ammoniacal silver nitrate is added to a solution containing an alkyne functional group, a white or yellowish precipitate of silver acetylide is formed. Silver acetylide is a highly explosive compound and is sparingly soluble in water, causing it to appear as a white or yellowish solid precipitate. This reaction is used as a test to detect the presence of an alkyne functional group in an organic compound.
In contrast, alkanes, alkenes, and alkanols do not react with ammoniacal silver nitrate, so they cannot decolorize it.
Therefore, an organic functional group that can likely decolorize ammoniacal silver nitrate is an alkyne.
Question 14 Report
The pollutant usually presents in a city which generates its electricity from coal?
Answer Details
The pollutant that is usually present in a city that generates its electricity from coal is sulfur dioxide (SO2), also known as sulfur(iv)oxide. When coal is burned to generate electricity, sulfur compounds in the coal are released into the air as SO2. This gas can react with other pollutants and atmospheric conditions to form smog, which can be harmful to human health and the environment. Therefore, it is important to reduce the use of coal in electricity generation and promote cleaner and more sustainable energy sources to reduce the levels of SO2 and other harmful pollutants in the air.
Question 15 Report
The following non-metal form acidic oxides with oxygen except?
Answer Details
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.
Question 16 Report
What is the shape of a molecule of CCl4?
Answer Details
The shape of a molecule of CCl4 is tetrahedral.
Question 17 Report
A sample of gas with an initial volume of 2.5 dm3 is heated and then allowed to expand to 7.5 dm3 at constant at pressure. What is the ratio of the final temperature of the initial absolute temperature?
Answer Details
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.
Question 18 Report
Which of the following statement is TRUE of the complete hydrolysis of a glyceride by sodium hydroxide?
Answer Details
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.
Question 19 Report
When marble is heated to 1473K, another whiter solid is obtained which reacts vigoriously with water to give an alkaline solution. The solution contains
Answer Details
The white solid obtained when marble (calcium carbonate, CaCO3) is heated to 1473K is calcium oxide (CaO), also known as quicklime. When quicklime reacts vigorously with water, it forms calcium hydroxide (Ca(OH)2), which is an alkaline solution. Therefore, the solution obtained from the reaction of quicklime with water contains calcium hydroxide (Ca(OH)2).
Question 20 Report
A quantity of air passed through a weighted amount of alkaline pyrogallol. An increase in the weight of the pyrogallol would result from the absorption of
Answer Details
When air is passed through alkaline pyrogallol, the oxygen in the air is absorbed by the pyrogallol, resulting in an increase in the weight of the pyrogallol. The other gases in air, namely nitrogen, neon, and argon, do not react with pyrogallol under these conditions.
Therefore, the answer is oxygen.
Question 21 Report
Mixing aqueos solution of barium hydroxide and sodium tetraoxocarbonate (iv) yields a white precipitate of
Answer Details
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.
Question 22 Report
Which of the following will precipitate in dil. HCl
Answer Details
Among the given options, only CuS will precipitate in dilute HCl.
CuS is insoluble in dilute HCl, and hence it will precipitate when added to dilute HCl. However, the other options will dissolve in dilute HCl, and hence they will not precipitate.
ZnS will dissolve in dilute HCl to form ZnCl2 and H2S.
Na2S will react with dilute HCl to produce H2S and NaCl.
FeS will dissolve in dilute HCl to form FeCl2 and H2S.
Therefore, the correct answer is (4) CuS.
Question 23 Report
The IUPAC nomenclature of the structure is
Answer Details
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".
Question 24 Report
Which of the following substances is not a homogeneous mixture?
Answer Details
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.
Question 25 Report
which of these compounds exhibits resonance
Answer Details
The compound that exhibits resonance is benzene.
Question 26 Report
How many bonding pair are present in carbon(iv)oxide?
Answer Details
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.
Question 28 Report
A metal which can be used as sacrificial anode for preventing corrosion of length of iron pipe is
Answer Details
Question 29 Report
The boiling point of water, ethanol, toulene and butan-2-ol are 373.0k, 351.3k, 383.6k and 372.5k respectively, which liquid has the highest vapour pressure at 323.0k
Question 30 Report
On the basis of the electrochemical series, which of these ions will show the greater tendency to be discharged at the cathode in an electrolytic cell
Answer Details
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.
Question 31 Report
Crude petroleum is converted to useful products by the process of?
Answer Details
The process of converting crude petroleum into useful products is known as fractional distillation. Crude petroleum is a mixture of different hydrocarbons, and fractional distillation separates these hydrocarbons based on their boiling points.
During the process of fractional distillation, crude petroleum is heated to a high temperature, and the resulting vapors are passed through a tower called a fractionating column. This column contains a series of trays, and each tray contains a specific temperature range. As the vapors rise up the column, they cool and condense into liquids on the tray with a temperature that matches their boiling point. The liquids are then collected and further refined into useful products like gasoline, diesel, jet fuel, and heating oil.
Fractional distillation is an important process because it allows us to separate and purify the different components of crude petroleum, which have different properties and uses. For example, gasoline has a lower boiling point and is more volatile than diesel fuel, which makes it ideal for use in cars. By separating these components, we can create products that meet specific needs and requirements.
Question 32 Report
The sub-atomic particles located in the nucleus of an atom are?
Answer Details
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.
Question 33 Report
Calcium forms complexes with ammonia because
Answer Details
The reason why calcium forms complexes with ammonia is that it has empty d-orbitals.
Question 34 Report
Which of the following roles does sodium chloride play in preparation? It
Answer Details
The role that sodium chloride (NaCl) plays in soap preparation is to separate soap from glycerol. When fats or oils are hydrolyzed with an alkali, such as sodium hydroxide (NaOH), the result is a mixture of soap and glycerol. Adding NaCl to this mixture helps to induce the precipitation of the soap, allowing it to be separated from the glycerol. This process is known as "salting out" and is used to purify the soap and remove impurities.
Sodium chloride does not react with glycerol or accelerate the decomposition of fat and oil. Also, it does not convert the fatty acid to its sodium salt as this conversion is done by the alkali (such as NaOH) during the saponification process.
Question 35 Report
When heat is absorbed during a chemical reaction, the reaction is said to be
Answer Details
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.
Question 36 Report
The reactions below represent neutralization reaction, in which of them is the value of ΔH highest?
Answer Details
The reaction with the highest ΔH (change in enthalpy) would be the reaction between HCL and NaOH, which forms NaCL and H2O.
This is because the formation of water releases energy in the form of heat, which is reflected in the positive ΔH value for this reaction. When an acid and a base react, they neutralize each other and form a salt and water, with the release of heat being a sign of an exothermic reaction.
Question 37 Report
Hard water is water with high concentrations of dissolved ions, in particular calcium and
Answer Details
Hard water is water that contains high amounts of dissolved minerals, specifically calcium and magnesium ions. These minerals come from the rocks and soil that the water flows through and can accumulate in the water as it travels to your home. When you use hard water, it can leave mineral deposits on your pipes, fixtures, and appliances, which can reduce their efficiency and lifespan. It can also make soap less effective and leave your skin feeling dry and itchy. Therefore, it is important to treat hard water if it is a problem in your area.
Question 38 Report
If the volume of a given mass of a gas at 0ºc is \(29.5\text{cm}^3\). What will be the volume of the gas at 15ºc, given that the pressure remains constant.
Question 39 Report
A certain volume of gas at 298k is heated such that its volume and pressure are now four times the original values. What is the new temperature?
Answer Details
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.
Question 40 Report
Which of the following will act as both oxidizing agents and reducing agents?
Answer Details
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.
