A sample of hard water contains some calcium sulphate and calcium hydrogen carbonate. The total hardness may therefore be removed by

adding excess calcium hydroxide

adding a calculated amount of calcium hydroxide

Beryllium and Aluminium have similar properties because they

are positioned diagonally to each other

The presence of ammonia gas in a desiccator can exclusively be removed by

concentrated tetraoxosulphate (VI) acid

The choice of method for extracting a metal from its ores depends on the

position of the metal in the electrochemical series

position of the metal in the periodic table

In the upper atmosphere, the ultra-violet light breaks off a free chlorine atom from chlorofluorocarbon molecule. The effect of this is that the free chlorine atom will

be very reactive and will attack ozone

be non-reactive and will not attack ozone

not change the level of ozone in the atmosphere

increase the level of ozone in the atmosphere

(I). 3CuO(s) + 2NH3(g) -----> 3Cu(s) + 3H2O(l) + N2(g) (II). 2NH3(g) + 3Cl2(g) -----> 6HCl(g) + N2(g) (III). 4NH3(g) + 3O2(g) -----> 6H2O(l) + N2(g) The reactions represented by the equations above demonstrate the

oxidizing properties of ammonia

The ionic radii of metals are usually

greater than their atomic radii

unaffected by the charge on the ion

Suitable reagents for the laboratory preparation nitrogen are

sodium dioxonitrate(III) and ammonium chloride

sodium trioxonitrate(V) and ammonium chloride

sodium chloride and ammonium trioxonitrate(V)

sodium chloride and ammonium di-ozonitrate(III)

The collision theory explains reaction rates in terms of

frequency of collision of the reactants

frequency of collision of the products

The solubility of the solids that dissolves in a given solvent with the liberation of heat will

increase with an increase in temperature

decrease with an increase in temperature

decrease with a decrease in temperature

not be affected by changes in temperature

The situation obtained when a perfect gas expands into a vacuum is

ΔH is zero and T Δ S is positive

ΔH is positive and TΔ S is zero

ΔH is positive and T Δ S is negative

ΔH is negative and TΔ S is zero

ΔH is zero and T Δ S is positive

In the laboratory preparation of oxygen, the gas cannot be collected by displacement of air because

the density of oxygen is greater than that of air

the density of air is nearly the same as that of oxygen

JAMB UTME - Chemistry - 2018 | Green Bridge CBT

Question 1 Report

Aluminium does not react with either dilute or concentrated trioxonitrate (V) acid because

it is insoluble in either dilute or concentrated trioxonitrate (V) acid

it is lower than hydrogen in the electrochemical series

the reaction with trioxonitrate (V) acid has a light activation energy

an insoluble oxide is formed on its surface which renders it passive

Non-metals And Their Compounds

View Answer

Question 2 Report

The general formula of alkanones is

RCHO

R

_{2}

CO

RCOOH

RCOOR

Chemistry Of Carbon Compounds (Nigeria Only)

View Answer

Question 3 Report

Calculate the percentage composition of oxygen in calcium trioxocarbonate(IV) [Ca=40, C=12, O=16]

16

48

40

12

Answer Details

To calculate the percentage composition of oxygen in calcium trioxocarbonate(IV), we first need to determine the molar mass of the compound. The compound has one calcium atom (Ca), one carbon atom (C), and three oxygen atoms (O). So, the molar mass of calcium trioxocarbonate(IV) can be calculated as follows: Molar mass = (1 × atomic mass of Ca) + (1 × atomic mass of C) + (3 × atomic mass of O) = (1 × 40) + (1 × 12) + (3 × 16) = 40 + 12 + 48 = 100 g/mol Next, we need to determine the mass of oxygen in one mole of calcium trioxocarbonate(IV). The compound has three oxygen atoms, each with an atomic mass of 16 g/mol. Therefore, the total mass of oxygen in one mole of the compound is: Mass of oxygen = 3 × 16 = 48 g/mol Finally, to determine the percentage composition of oxygen in calcium trioxocarbonate(IV), we divide the mass of oxygen by the molar mass of the compound and multiply by 100. Percentage of oxygen = (Mass of oxygen / Molar mass of compound) × 100 = (48 / 100) × 100 = 48% Therefore, the correct answer is 48, which represents the percentage composition of oxygen in calcium trioxocarbonate(IV).

Read lesson note on Chemical Combination (JAMB)

Chemical Combination

View Answer

Question 4 Report

Methanoic acid mixes with water in all proportions and has about the same boiling point as water. Which of the following methods would you adopt to obtain pure water from a mixture of Sand, water and methanoic acid?

Fractional distillation

Filtration followed by distillation

Neutralization with sodium hydroxide followed by distillation

Neutralization with sodium hydroxide followed by filtration

Acids, Bases And Salts (Ghana Only)

View Answer

Question 5 Report

The Consecutive members of an alkane homologous series differ by

CH

_{2}

CH

_{3}

C

_{n}

H

_{n}

Answer Details

The consecutive members of an alkane homologous series differ by a CH2 unit. This means that each successive member of the alkane series has one more CH2 unit than the previous member. For example, consider the simplest alkane, methane (CH4). The next member of the series is ethane (C2H6), which differs from methane by one CH2 unit. The next member after that is propane (C3H8), which differs from ethane by another CH2 unit. This pattern continues for all members of the alkane homologous series. The reason for this is that each carbon atom in the alkane chain must be bonded to four other atoms, which are usually hydrogen atoms. This means that each carbon atom in the chain can only bond to one other carbon atom. Therefore, the length of the alkane chain can only increase by adding CH2 units to the end of the chain. In summary, the consecutive members of an alkane homologous series differ by a CH2 unit because this is the only way to add length to the alkane chain while maintaining the required number of bonds for each carbon atom in the chain.

Read lesson note on Chemical Equilibria (JAMB)

Chemical Equilibria

View Answer

Question 6 Report

What volume of oxygen will remain after reacting 8cm of hydrogen gas with 20cm of oxygen gas

10cm

^{3}

12cm

^{3}

14cm

^{3}

16cm

^{3}

Kinetic Theory Of Matter And Gas Laws

Energy And Energy Changes

View Answer

Question 7 Report

The hydrogen ion concentration of a sample of orange juice is 2.0 X 10\(^{-11}\)moldm\(^{-3}\). What is its p\(^{OH}\)? [log102 = 0.3010]

3.30

13.00

10.70

11.30

Acids, Bases And Salts (Ghana Only)

View Answer

Question 8 Report

In the preparation of oxygen by heating KCIO\(_2\), in the presence of MnO\(_2\) only moderate heat is needed because the catalyst acts by

lowering the pressure of the reaction

increasing the surface area of the reaction

increasing the rate of the reaction

lowering the energy barrier of the reaction

Answer Details

The presence of MnO2 acts as a catalyst in the reaction of KCIO2 to produce oxygen. A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the reaction itself. MnO2 acts by lowering the energy barrier of the reaction, which means it reduces the amount of energy required for the reaction to take place. This makes it easier for the reaction to occur, and thus the reaction proceeds at a faster rate. As a result, only moderate heat is needed to provide the initial energy required for the reaction to start. Therefore, the correct answer is: lowering the energy barrier of the reaction.

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

Kinetic Theory Of Matter And Gas Laws

View Answer

Question 9 Report

In the reaction between sodium hydroxide and sulphuric acid solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralise 10cm3 of 1.25 molar sulphuric acid?

5cm

^{3}

10cm

^{3}

20cm

^{3}

50cm

^{3}

Stoichiometry And Chemical Reactions

View Answer

Question 10 Report

2KClO3(g) MNO3? 2KCl(s) + 3O2(g)

The importance of the catalyst in the reaction above is that

heating may not be required before the reaction takes place

the reaction is controllable even at a high temperature

the reaction produces large quantity of oxygen

the reaction takes place more rapidly at a lower temperature

Stoichiometry And Chemical Reactions

View Answer

Question 11 Report

What is the concentration of a solution containing 2g of NaOH in 100cm3 of solution? [Na = 23, O =16, H = 1]

0.40 moldm

^{- 3}

0.50 moldm

^{- 3}

0.05 moldm

^{- 3}

0.30 moldm

^{- 3}

Answer Details

The concentration of a solution containing 2g of NaOH in 100cm3 of solution is 0.40 moldm-3. This can be calculated by using the formula: molarity (M) = number of moles of solute / volume of solution (in liters) First, we need to calculate the number of moles of NaOH in the solution. The molar mass of NaOH is (23 + 16 + 1) = 40 g/mol. So, 2g of NaOH is equal to 2/40 = 0.05 moles. Next, we need to convert the volume of the solution from cm3 to liters. 1 cm3 = 0.001 liters, so 100 cm3 = 0.1 liters. Finally, we can calculate the molarity as follows: M = 0.05 moles / 0.1 liters = 0.5 mol/L = 0.50 moldm-3 So, the concentration of the solution is 0.50 moldm-3.

Read lesson note on Solubility Of Substances (Ghana Only) (WAEC)

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

Read lesson note on Periodic Chemistry (Ghana Only) (WAEC)

Solubility Of Substances (Ghana Only)

Kinetic Theory Of Matter And Gas Laws

Periodic Chemistry (Ghana Only)

View Answer

Question 12 Report

In the shown experiment (Fig. 1) the litmus paper will initially

be bleached

turn green

turn red

turn blue

Acids, Bases And Salts

View Answer

Question 13 Report

Which of these sources of water may likely contain the least concentration of Ca\(^{2+}\) and Mg\(^{2+}\)?

Spring water

River water

Tap water

Sea water

Answer Details

The source of water that is likely to contain the least concentration of Ca2+ and Mg2+ is tap water. Tap water is treated and processed before it is made available for consumption, which often involves removing minerals such as calcium and magnesium. Spring water and river water, on the other hand, are naturally occurring and generally contain higher levels of minerals. Sea water has the highest concentration of minerals, including Ca2+ and Mg2+.

Read lesson note on Water (JAMB)

Water

View Answer

Question 14 Report

The radio isotope used in industrial radiography for the rapid checking of faults in welds and casting is?

carbon-14

phosphorus-32

cobalt

iodine-131

Chemistry Of Carbon Compounds (Nigeria Only)

View Answer

Question 15 Report

Which of the following are mixtures?

I. Petroleum

II. Rubber latex

III. Vulcanizer's solution

IV. Carbon sulphide

I, II and III

I, II and IV

I and II only

I and IV

Separation Of Mixtures And Purification Of Chemical Substances

View Answer

Question 16 Report

At what temperature is the solubility of potassium trioxonitrate(V ) equal to that of sodium trioxonitrate (V)?

0

^{o}

c

30

^{o}

c

40

^{o}

c

45

^{o}

c

Solubility

View Answer

Question 17 Report

A basic postulate of the kinetic theory of gases is that the molecules of a gas move in straight lines between collisions. This implies that

collisions are perfectly elastic

forces of repulsion exis

forces of repulsion and attraction are in equilibrium

collisions are inelastic

Kinetic Theory Of Matter And Gas Laws

View Answer

Question 18 Report

Which of the following statements is correct about the periodic table?

Elements in the same period have the same number of valence electrons

The valence electrons of the elements in the same period increase progressively across the period

Elements in the same group have the same number of electron shells

The non-metallic Properties of the elements tend to decrease across each period

Atomic Structure And Bonding

View Answer

Question 19 Report

The conductivity of an acid solution depends on the

amount of ions present and their mobilities

mobilities of the ions present

amount of ions present

temperature of the solution

Answer Details

The conductivity of an acid solution depends on the amount of ions present and their mobilities. When an acid dissolves in water, it forms ions that can carry an electric charge. These ions are what allows the solution to conduct electricity. The more ions there are in the solution, the better it can conduct electricity. However, not all ions have the same mobility or ability to move around in the solution. Ions with a higher mobility can move more easily through the solution, leading to a higher conductivity. Therefore, the conductivity of an acid solution is determined by both the amount of ions present and their mobilities. Other factors such as temperature can also affect conductivity, but the primary factors are the amount and mobility of ions.

Read lesson note on Chemical Bonds (Ghana Only) (WAEC)

Read lesson note on Acids, Bases And Salts (Ghana Only) (WAEC)

Read lesson note on Periodic Chemistry (Ghana Only) (WAEC)

Chemical Bonds (Ghana Only)

Acids, Bases And Salts (Ghana Only)

Periodic Chemistry (Ghana Only)

View Answer

Question 20 Report

\(3\mathrm{H}_2(g) + \mathrm{N}_2 \rightleftharpoons 2\mathrm{NH}_3(g)\); H= -ve

In the reaction above, lowering of temperature will

have no effect on the equilibrium position

increase the rate of both the forward and reverse reactions equally

favour the forward reactio

favour the reverse reaction

Chemical Kinetics And Equilibrium Systems (Ghana Only)

View Answer

Question 21 Report

Elements P, Q, R, S have 6, 11, 15, 17 electrons respectively, therefore,

P will form an electrovalent bond with R

Q will form a covalent bond with S

R will form an electrovalent bond with S

Q will form an electrovalent bond with S

Answer Details

Elements form bonds with other elements in order to attain a stable electron configuration, like the one found in noble gases. There are two types of bonds: covalent and ionic (also called electrovalent). In covalent bonds, two elements share electrons to attain a stable electron configuration. This type of bond is formed between two non-metal elements. In ionic bonds, one element donates electrons to another element, creating ions. This type of bond is formed between a metal and a non-metal element. Based on the information given, we can deduce the following: - P is a metal, as it has only 6 electrons. - Q is a non-Metal, as it has 11 electrons. - R is a metal, as it has 15 electrons. - S is a non-Metal, as it has 17 electrons. So, from this information, we can conclude that: - P will form an ionic bond with R, as P is a metal and R is a metal. - Q will form a covalent bond with S, as Q is a non-Metal and S is a non-Metal. Therefore, the correct answer is "Q will form a covalent bond with S."

Read lesson note on Atomic Structure And Bonding (JAMB)

Atomic Structure And Bonding

View Answer

Question 22 Report

To what temperature must a gas at 273k be heated in order to double both its volume and pressure?

298K

546K

819K

1092K

Kinetic Theory Of Matter And Gas Laws

View Answer

Question 23 Report

If one of the following oxides is heated with hydrogen or carbon using a bunsen burner. it is not reduced to the metal, Which one is it?

lead oxide

Magnesium oxide

Copper oxide

Tin oxide

Answer Details

The oxide that cannot be reduced to the metal when heated with hydrogen or carbon using a Bunsen burner is magnesium oxide. Magnesium oxide is an ionic compound made up of positively charged magnesium ions and negatively charged oxygen ions. When heated with hydrogen or carbon, the oxygen ions are not easily removed from the compound. This is because the ionic bond between the magnesium and oxygen ions is very strong and requires a lot of energy to break. On the other hand, lead oxide, copper oxide, and tin oxide are all metal oxides and can be reduced to the metal by heating with hydrogen or carbon. This is because they have a weaker bond between the metal and oxygen ions, allowing the oxygen to be removed more easily when heated. In conclusion, magnesium oxide is the oxide that cannot be reduced to the metal when heated with hydrogen or carbon using a Bunsen burner.

Read lesson note on Oxidation And Reduction (JAMB)

Oxidation And Reduction

View Answer

Question 24 Report

According to the Kinetic Theory an increase in temperature causes the kinetic energy of particles to

decrease

increase

be zero

remain constant

Answer Details

The kinetic energy of particles increases with an increase in temperature. In the Kinetic Theory, temperature is related to the average kinetic energy of the particles in a substance. The higher the temperature, the faster the particles move, and the more energy they have. Think of it like this: if you throw a ball, it will have more energy and travel farther if you throw it harder. Similarly, if you heat up a substance, its particles will move faster and have more energy. So, the answer is that an increase in temperature causes the kinetic energy of particles to increase.

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

Kinetic Theory Of Matter And Gas Laws

View Answer

Question 25 Report

Sieving is a technique used to separate mixtures containing solid particles of

small sizes

large sizes

different sizes

the same size

Answer Details

Sieving is a technique used to separate mixtures containing solid particles of different sizes. A sieve is a mesh or perforated screen that is used to separate particles based on their size. The mixture is poured onto the sieve, and the particles that are too large to pass through the holes are left on top, while the smaller particles fall through the holes and are collected below. This process allows for the separation of the different-sized particles, making it easier to purify or further process the mixture.

Read lesson note on Separation Of Mixtures And Purification Of Chemical Substances (JAMB)

Separation Of Mixtures And Purification Of Chemical Substances

View Answer

Question 26 Report

If 1 litre of 2.2M sulphuric acid is poured into a bucket containing 10 litres of water and the resulting solution mixed thoroughly, the resulting sulphuric acid concentration will be

2.2M

1.1M

0.22M

0.11M

Answer Details

When 1 liter of 2.2M sulphuric acid is added to 10 liters of water, the total volume of the resulting solution is 11 liters. To find the resulting concentration of sulphuric acid, we need to use the equation: M1V1 = M2V2 where M1 is the initial concentration, V1 is the initial volume, M2 is the final concentration, and V2 is the final volume. We can plug in the values we know: M1 = 2.2M (the initial concentration of the sulphuric acid) V1 = 1L (the initial volume of the sulphuric acid) M2 = ? (the final concentration we're trying to find) V2 = 11L (the final volume of the resulting solution) Solving for M2, we get: M2 = (M1 x V1) / V2 M2 = (2.2M x 1L) / 11L M2 = 0.2M Therefore, the resulting sulphuric acid concentration is 0.2M or 0.2 moles per liter. In summary, when 1 liter of 2.2M sulphuric acid is mixed with 10 liters of water, the resulting sulphuric acid concentration is diluted to 0.2M. This is because the total volume of the resulting solution is greater than the initial volume of the sulphuric acid, which leads to a decrease in concentration.

Read lesson note on Acids, Bases And Salts (Ghana Only) (WAEC)

Acids, Bases And Salts (Ghana Only)

View Answer

Question 27 Report

Calculate the pH of \(0.05\ \mathrm{mol\,dm^{-3}}\ \mathrm{H_2SO_4}\)

1.30

1.12

1.00

0.30

Answer Details

To solve this problem, we need to use the formula for calculating the pH of a solution, which is: pH = -log[H+] where [H+] is the concentration of hydrogen ions in moles per liter. The given chemical equation is: H2SO4 + 2H2O → 2H3O+ + SO42- From this equation, we can see that one molecule of sulfuric acid (H2SO4) can donate two hydrogen ions (H+) to the solution, which means that the concentration of hydrogen ions is twice the concentration of sulfuric acid. Therefore, the concentration of hydrogen ions in this solution is: [H+] = 2 x 0.05 moldm^-3 = 0.1 moldm^-3 Now we can use the formula for pH: pH = -log[H+] pH = -log(0.1) pH = 1.00 Therefore, the pH of the solution is 1.00.

Read lesson note on Periodic Chemistry (Ghana Only) (WAEC)

Periodic Chemistry (Ghana Only)

View Answer

Question 28 Report

The lUPAC name for

1-methyl pentane

3-methylbutane

2-methylbutane

1-dimethyl propane

View Answer

Question 29 Report

\(2\mathrm{SO}_2\,(g) + \mathrm{O}_2\,(g) \leftrightarrow 2\mathrm{SO}_3\,(g)\quad \Delta H = -395.7\mathrm{kJmol}^{-1}\)

In the equation, an increase in temperature will shift the equilibrium position to the

left and equilibrium constant decreases

left and equilibrium constant increases

right and equilibrium constant increases

right and equilibrium constant decreases

Chemical Equilibria

View Answer

Question 30 Report

An element used in the production of matches is

nitrogen

aluminium

copper

sulphur

Answer Details

The element used in the production of matches is sulphur. Matches are small sticks made of wood or cardboard with a chemical mixture at one end. This chemical mixture, called the match head, contains several compounds including sulphur. When the match is struck against a rough surface, the friction generates heat that ignites the sulphur in the match head, causing a flame. This flame then ignites the other compounds in the match head, which in turn ignites the wood or cardboard stick. Sulphur is an important component of the match head because it is highly flammable and burns easily. It also helps to ignite the other compounds in the match head. However, sulphur by itself is not a good fuel, which means that it cannot sustain a flame on its own. Therefore, it needs other combustible materials, such as potassium chlorate or phosphorus, to make the match head burn. Overall, sulphur plays a crucial role in the chemistry of matches and allows us to easily start fires for various purposes.

Read lesson note on Non-metals And Their Compounds (JAMB)

Non-metals And Their Compounds

View Answer

Question 31 Report

The elements in the periodic table are listed in order of increasing

relative atomic number

atomic mass

relative isotopic mass

nuclear charge

Atomic Structure And Bonding

View Answer

Question 32 Report

During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment

the litmus turns blue but no gas is evolved

the litmus turns blue and oxygen is evolved

the litmus turns blue and hydrogen is evolved

the litmus turns red and oxygen is evolved

Answer Details

During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment, the litmus will turn red and oxygen gas will be evolved. This is because during electrolysis, the positively charged copper ions (Cu2+) in the copper II sulphate solution are attracted to the negative cathode electrode, where they gain electrons and are reduced to form solid copper. At the same time, the negatively charged sulphate ions (SO42-) are attracted to the positive anode electrode, where they lose electrons and are oxidized to form oxygen gas and water. The litmus added to the anode compartment turns red because of the formation of oxygen gas, which is a highly reactive oxidizing agent that can react with the litmus to cause it to turn red. No hydrogen gas is evolved because hydrogen is produced at the cathode, which is in a separate compartment from the anode where the litmus is added.

Read lesson note on Electrolysis (JAMB)

Electrolysis

View Answer

Question 33 Report

Which of these alloys contains copper?

solder

steel

permallory

bronze

Answer Details

Bronze is the alloy that contains copper. Bronze is a metal alloy composed of copper and typically other elements such as tin, aluminum, silicon, or nickel. It is known for its strength, durability, and corrosion resistance. In fact, bronze is one of the earliest alloys created by humans, and it has been used for thousands of years to make tools, weapons, and decorative objects. Solder is an alloy of lead, tin, and sometimes other metals that is used to join metals together by melting the solder and allowing it to flow into the joint. Steel is an alloy of iron and carbon, and sometimes other elements like chromium, nickel, or manganese, that is known for its strength and durability. Permallory is a nickel-iron alloy with high magnetic permeability and low coercive force, which makes it useful in the production of electrical and electronic equipment. None of these alloys contain copper.

Read lesson note on Metals And Their Compounds (JAMB)

Metals And Their Compounds

View Answer

Question 34 Report

The periodic classification is an arrangement of the elements

atomic weights

isotopic weights

molecular weights

atomic numbers

Answer Details

The periodic classification is an arrangement of the elements based on their atomic numbers. The periodic table is a chart that lists all the known chemical elements in order of increasing atomic number, arranged in rows and columns according to their electronic structure and chemical properties. The atomic number of an element is the number of protons in the nucleus of an atom of that element. Each element has a unique atomic number, which determines its position in the periodic table. The elements are arranged in rows called periods, and in columns called groups or families. Elements in the same group have similar properties because they have the same number of valence electrons, which are the electrons in the outermost shell of the atom. The periodic table is an incredibly useful tool for chemists because it allows them to predict the properties of elements based on their position in the table. For example, elements in the same group tend to form similar compounds, so if you know the properties of one element in a group, you can often predict the properties of the other elements in that group. In summary, the periodic classification is an arrangement of the elements based on their atomic numbers. The periodic table is a chart that organizes the elements into rows and columns based on their electronic structure and chemical properties, allowing scientists to make predictions about the behavior of the elements based on their position in the table.

Read lesson note on Atomic Structure And Bonding (JAMB)

Atomic Structure And Bonding

View Answer

Question 35 Report

Which of the following is an example of a chemical change?

dissolution of salt in water

rusting of iron

melting of ice

separating a mixture by distillation

Acids, Bases And Salts

View Answer

Question 36 Report

Which of the following separation techniques can be employed in obtaining solvent from its solution?

Evaporation

Distillation

Filtration

Precipitation

Answer Details

The separation technique that can be employed in obtaining a solvent from its solution is evaporation. Evaporation is a process that involves heating a solution to vaporize the solvent, leaving behind the solute. The vaporized solvent can then be condensed and collected as a pure liquid. This technique is commonly used in industry and laboratory settings to recover solvents from solutions, as it is a simple and effective way to purify liquids. Distillation can also be used to separate a solvent from a solution, but it is a more complex process that involves boiling the solution and then condensing the vapors in a separate apparatus. Filtration and precipitation are not suitable for separating a solvent from a solution, as they are primarily used to separate solid particles from a liquid mixture.

Read lesson note on Solubility (JAMB)

Solubility

View Answer

Question 37 Report

The boiling of fat and aqueous caustic soda is referred to as

hydrolysis

esterification

acidification

saponification

Answer Details

The boiling of fat and aqueous caustic soda is referred to as saponification. Saponification is the process of converting fat into soap through a reaction with an alkaline substance, such as caustic soda. The reaction results in the formation of soap (a salt of a fatty acid) and glycerol. This process is important in the manufacture of soap, as it allows the fat to be converted into a useful cleaning product.

Read lesson note on Acids, Bases And Salts (JAMB)

Acids, Bases And Salts

View Answer

Question 38 Report

The salt that reacts with dilute hydrochloric acid to produce a pungent smelling gas which decolourizes acidified purple potassium tetraoxomanganate (VII) solution is

Na

_{2}

SO

_{4}

Na

_{2}

SO

_{3}

Na

_{2}

S

Na

_{2}

CO

_{3}

Acids, Bases And Salts

View Answer

Question 39 Report

In electrovalency, the oxidation number of the participating metal is always

decreasing

increasing

constant

neutral

View Answer

Question 40 Report

When air which contains the gases Oxygen, nitrogen, carbondioxide, water vapour and the rare gases, is passed through alkaline pyrogallol and then over quicklime, the only gases left are;

nitrogen and carbondioxide

the rare gases

nitrogen and oxygen

nitrogen and the rare gases

Air

View Answer






Press & Hold to Drag Around
Click Here to Close