Question:

What properties of water make it useful as a solvent? What type of compound can it (i) dissolve and (ii) hydrolyse?

Answer:

i) Water can dissolve ionic compounds, polar molecules, and some organic compounds.

ii) Water can hydrolyse (break down) esters, amides, and other organic compounds.

Question:

How does H2O2 behave as a bleaching agent.

Answer:

Step 1: Understand what a bleaching agent is.

Step 2: Research how H2O2 behaves as a bleaching agent.

Step 3: Analyze the results of your research to understand how H2O2 behaves as a bleaching agent.

Question:

Do you expect different products in solution when aluminium(III) chloride and potassium chloride treated separately with (i) normal water (ii) acidified the water, and (iii) alkaline water? Write equations wherever necessary.

Answer:

(i) When aluminium(III) chloride and potassium chloride are treated separately with normal water, no reaction will take place as both are insoluble in water.

(ii) When aluminium(III) chloride and potassium chloride are treated separately with acidified water, aluminium(III) chloride will react with water to form aluminium hydroxide and hydrochloric acid.

AlCl3 + 3H2O → Al(OH)3 + 3HCl

Potassium chloride will dissolve in water to form potassium ions and chloride ions.

KCl → K+ + Cl-

(iii) When aluminium(III) chloride and potassium chloride are treated separately with alkaline water, aluminium(III) chloride will react with water to form aluminium hydroxide and hydrochloric acid.

AlCl3 + 3H2O → Al(OH)3 + 3HCl

Potassium chloride will react with water to form potassium hydroxide and hydrochloric acid.

KCl + H2O → KOH + HCl

Question:

Arrange the following LiH,NaH and CsH in order of increasing ionic character.

Answer:

1. LiH
2. NaH
3. CsH

LiH < NaH < CsH

Question:

Complete the following chemical reaction and classify into (a) hydrolysis, (b) redox and (c) hydration reaction.

Answer:

NH4OH + HCl → NH4Cl + H2O

(c) Hydration reaction

Question:

AlCl3(g)+H2O(l)→

Answer:

1. AlCl3(g) + 3H2O(l) → Al(OH)3(s) + 3HCl(g)

2. AlCl3(g) + 3H2O(l) → Al(OH)3(aq) + 3HCl(aq)

Question:

Is demineralised or distilled water useful for drinking purposes? If not, how can it be made useful?

Answer:

Step 1: Demineralised or distilled water does not contain minerals, so it is not suitable for drinking purposes.

Step 2: To make it useful for drinking, it must be re-mineralised by adding minerals such as calcium, magnesium, and sodium back into the water.

Step 3: This can be done by adding mineral drops or tablets to the water. Alternatively, it can be re-mineralised naturally by allowing it to sit in an open container for several hours, allowing minerals from the air to dissolve in the water.

Question:

What properties of water make it useful as a solvent? What type of compound can it (i) dissolve and (ii) hydrolyse?

Answer:

i. Water is useful as a solvent because it has a high polarity, which allows it to form hydrogen bonds with other molecules. This enables it to dissolve polar molecules, such as salts, sugars, and acids. It can also dissolve non-polar molecules, such as hydrocarbons and lipids.

ii. Water can hydrolyse compounds such as proteins, nucleic acids, and polysaccharides. This is because the water molecules can break the bonds between the atoms in the compounds, resulting in smaller molecules.

Question:

What properties of water make it useful as a solvent? What type of compound can it (i) dissolve and (ii) hydrolyse?

Answer:

i) Water can dissolve ionic compounds, polar molecules, and some organic compounds.

ii) Water can hydrolyse covalent bonds and ionic bonds.

Question:

Complete the following reactions: (i) H2(g)+MmOo(s)→Δ (ii) CO(g)+H2(g)Δcatalyst (iii) C3H8(g)+3H2O(g)Δcatalyst (iv) C3H8(g)+3H2O(g)Δcatalyst

Answer:

(i) H2(g)+MmOo(s)→H2O(g) +Mm(s)

(ii) CO(g)+H2(g)→CO2(g)+H2O(g) (catalyst required)

(iii) C3H8(g)+3H2O(g)→3CO2(g)+4H2O(g) (catalyst required)

(iv) C3H8(g)+5O2(g)→3CO2(g)+4H2O(g) (catalyst required)

Question:

Saline hydrides are known to react with water violently producing fire. Can CO2, a well known fire extinguisher, be used in this case? Explain.

Answer:

1. Saline hydrides are compounds that contain a metal cation bonded to a hydrogen anion, such as NaH or LiH.

2. These compounds are known to react with water violently, producing heat and sometimes fire.

3. Carbon dioxide (CO2) is a well-known fire extinguisher because it reduces the amount of oxygen in the air, which is necessary for combustion.

4. However, CO2 is not effective in this case because it does not react with the saline hydrides. The reaction of saline hydrides with water is an exothermic reaction, meaning it produces heat and fire, and CO2 does not react with the hydrides, so it cannot stop the reaction.

Question:

What do you understand by the term ‘auto-protolysis’ of water? What is its significance?

Answer:

1. Auto-protolysis of water is a process in which water molecules can break down into ions, such as H+ and OH-.

2. This process is significant because it is an important factor in the acid-base balance of aqueous solutions. It also helps to maintain the pH of a solution by providing an equilibrium between the two ions. This process is also responsible for the buffering capacity of water, which helps to keep the pH of a solution relatively constant.

Question:

Consider the reaction of water with F2 and suggest in terms of oxidation and reduction which species are oxidised/reduced.

Answer:

Step 1: The reaction of water with F2 is as follows: 2F2 + 2H2O → 4HF + O2

Step 2: In this reaction, F2 is being oxidised (losing electrons) and H2O is being reduced (gaining electrons). Therefore, F2 is being oxidised and H2O is being reduced.

Question:

How can the production of dihydrogen, obtained from coal gasification, be increased?

Answer:

1. Increase the temperature of the gasification process to maximize the yield of dihydrogen.

2. Optimize the steam/carbon ratio in the gasification process to maximize the production of dihydrogen.

3. Improve the catalysts used in the gasification process to increase the production of dihydrogen.

4. Increase the pressure of the gasification process to maximize the yield of dihydrogen.

5. Utilize a higher quality coal feedstock to maximize the production of dihydrogen.

Question:

Complete the following reactions: H2(g)+MmOo(s)→Δ

Answer:

1. Break down the reactants into their component elements: H2(g) –> 2H (g) MmOo(s) –> M (s) + m (s) + O (s) + o (s)

2. Balance the equation: 2H (g) + M (s) + m (s) + O (s) + o (s) → Δ

3. Determine the products of the reaction: The products of the reaction are likely to be a combination of the components of the reactants, such as H2O, MmOo2, or other compounds.

Question:

Arrange the following in order of increasing reducing property. NaH, MgH2 and H2O

Answer:

1. H2O
2. MgH2
3. NaH

Question:

Complete the following chemical reactions. Classify the below into (a) hydrolysis, (b) redox and (c) hydration reactions. (i) PbS(s)+H2O2(aq)→ (ii) MnO4−(aq)+H2O2(aq)→ (iii) CaO(s)+H2O(g)→ (iv) AlCl3(g)+H2O(l)→ (v) Ca3N2(s)+H2O(l)→

Answer:

(i) Redox (ii) Redox (iii) Hydration (iv) Hydrolysis (v) Hydrolysis

Question:

Define hydrogenation.

Answer:

1. Hydrogenation is a chemical reaction between molecules of hydrogen and other molecules, such as unsaturated fats, to produce a more stable, saturated form.

2. The process involves adding hydrogen atoms to the double or triple bonds between atoms in a molecule.

3. The result is a more stable, saturated form of the molecule, which is often more solid at room temperature.

4. Hydrogenation is used in the food industry to make products such as margarine and shortening. It is also used in the production of lubricants and other industrial products.

Question:

Complete the following chemical reaction and classify into (a) hydrolysis, (b) redox and (c) hydration reactions. MnO4−(aq)+H2O2(aq)→

Answer:

Answer: (c) Hydration Reaction MnO4−(aq) + H2O2(aq) → MnO2(s) + O2(g) + H2O(l)

Question:

Describe the usefulness of water in biosphere and biological systems.

Answer:

1. Water is essential for all life on Earth. It is the primary solvent that allows for the transport of nutrients and waste products in biological systems.

2. Water is also important for temperature regulation in living organisms, as it has a high heat capacity.

3. Water is a reactant in many biochemical reactions, and it is necessary for the formation of proteins, carbohydrates, and lipids.

4. Water also helps to maintain the pH balance in biological systems, and it is essential for the formation of cell membranes.

5. Finally, water is essential for photosynthesis, which is the process by which plants use light energy to produce food.

Question:

Knowing the properties of H2O and D2O. Do you think that D2O can be used for drinking purposes?

Answer:

Step 1: Understand the properties of H2O and D2O.

Step 2: Compare the properties of H2O and D2O.

Step 3: Analyze the differences between the two molecules.

Step 4: Evaluate the potential risks associated with drinking D2O.

Step 5: Consider the potential benefits of using D2O for drinking purposes.

Step 6: Make a conclusion on whether D2O can be used for drinking purposes.

Question:

What is the difference between the terms hydrolysis and hydration?

Answer:

Step 1: Understand the definitions of hydrolysis and hydration.

Hydrolysis is a chemical reaction in which a molecule is broken down into two parts by the addition of water molecules.

Hydration is the process of adding water molecules to a substance in order to increase its volume or to make it more soluble.

Step 2: Compare and contrast the two terms.

The main difference between hydrolysis and hydration is that hydrolysis involves breaking down a molecule into two parts, while hydration involves adding water molecules to a substance to increase its volume or make it more soluble.

Question:

How can saline hydrides remove traces of water from organic compounds?

Answer:

Step 1: Understand the meaning of the terms used in the question.

Saline hydrides are compounds composed of a metal cation and a hydride anion. They are used as a drying agent to remove traces of water from organic compounds.

Step 2: Research the process of using saline hydrides to remove traces of water from organic compounds.

The process of using saline hydrides to remove traces of water from organic compounds involves adding the saline hydride to the organic compound, which then reacts with the water to form a hydrate. The hydrate is then removed by filtration or distillation.

Step 3: Understand the implications of using saline hydrides to remove traces of water from organic compounds.

Using saline hydrides to remove traces of water from organic compounds can be beneficial, as it can help to improve the purity of the organic compound. In addition, it can also help to reduce the risk of contamination, as any water present in the organic compound can be removed.

Question:

What do you expect the nature of hydrides is, if formed by elements of atomic numbers 15, 19, 23 and 44 with dihydrogen? Compare their behaviour towards water.

Answer:

1. Hydrides are compounds formed when hydrogen combines with another element.

2. The elements of atomic numbers 15, 19, 23 and 44 are phosphorus (P), potassium (K), vanadium (V) and ruthenium (Ru) respectively.

3. When dihydrogen combines with these elements, the hydrides formed are phosphine (PH3), potassium hydride (KH), vanadium hydride (VH2) and ruthenium hydride (RuH2).

4. All of these hydrides are highly reactive and flammable.

5. When these hydrides come in contact with water, they react to form the corresponding hydroxides and release hydrogen gas. For example, phosphine reacts with water to form phosphoric acid and release hydrogen gas.

Question:

What do you understand by (i) electron-deficient, (ii) electron-precise, and (iii) electron-rich compounds of hydrogen?

Answer:

(i) Electron-deficient compounds of hydrogen are compounds in which there are fewer electrons than the normal number of electrons. These compounds are usually unstable and highly reactive. Examples of electron-deficient compounds of hydrogen include hydrazine and hydrofluoric acid.

(ii) Electron-precise compounds of hydrogen are compounds in which the number of electrons is exactly the same as the number of protons in the compound. These compounds are usually stable and unreactive. Examples of electron-precise compounds of hydrogen include hydrogen gas and water.

(iii) Electron-rich compounds of hydrogen are compounds in which there are more electrons than the normal number of electrons. These compounds are usually stable and unreactive. Examples of electron-rich compounds of hydrogen include ammonia and hydrochloric acid.

Question:

What do you understand by the term non-stoichiometric hydrides? Do you expect this type of the hydrides to be formed by alkali metals? Justify your answer.

Answer:

Answer:

Non-stoichiometric hydrides are hydrides that contain more or less hydrogen atoms than the stoichiometric ratio. For example, LiH0.8 is a non-stoichiometric hydride, which has 8/10 of the hydrogen atoms present in the stoichiometric ratio of LiH.

No, I do not expect this type of hydride to be formed by alkali metals. Alkali metals typically form hydrides with the stoichiometric ratio, so non-stoichiometric hydrides are unlikely to be formed by alkali metals.

Question:

Among NH3, H2O and HF, which would you expect to have highest magnitude of hydrogen bonding and why?

Answer:

1. Hydrogen bonding is a type of intermolecular force that involves the attraction between a hydrogen atom covalently bonded to a highly electronegative atom (such as N, O, or F) and another highly electronegative atom.

2. Among NH3, H2O and HF, HF would be expected to have the highest magnitude of hydrogen bonding because it has the highest electronegativity of the three molecules. This means that the hydrogen atom in HF is more strongly attracted to the fluorine atom, resulting in a stronger hydrogen bond.

Question:

Arrange the following. (i) CaH2, BeH2 and TiH2 in order of increasing electrical conductance. (ii) LiH,NaH and CsH in order of increasing ionic character. (iii) H−H,D−D and F−F in order of increasing bond dissociation enthalpy. (iv) NaH,MgH2 and H2O in order of increasing reducing property.

Answer:

(i) BeH2 < TiH2 < CaH2 (ii) LiH < NaH < CsH (iii) D−D < H−H < F−F (iv) NaH < MgH2 < H2O

Question:

Explain syngas in detail.

Answer:

Syngas (or synthesis gas) is a mixture of carbon monoxide (CO) and hydrogen (H2) gases, which is produced through various industrial processes. It is used as a fuel and as a raw material in the production of chemicals, such as methanol, ammonia, and synthetic fuels. Syngas can also be produced from renewable sources, such as biomass and waste.

Step 1: Syngas is a mixture of two gases: carbon monoxide (CO) and hydrogen (H2).

Step 2: Syngas is produced through various industrial processes, such as gasification, partial oxidation, and steam reforming.

Step 3: Syngas is used as a fuel and a raw material in the production of chemicals.

Step 4: Syngas can also be produced from renewable sources, such as biomass and waste.

Question:

Complete the following chemical reaction and classify the into (a) hydrolysis, (b) redox and (c) hydration reactions.

Answer:

Na2CO3 + HCl → NaCl + H2O + CO2

(c) Hydration reaction

Question:

CaO(s)+H2O(g)→

Answer:

1. Balance the equation: CaO(s) + H2O(g) → Ca(OH)2(s)

2. Identify the reactants: CaO(s) and H2O(g) are the reactants.

3. Identify the product: Ca(OH)2(s) is the product.

Question:

What do you understand by electron deficient compounds of hydrogen.

Answer:

1. Electron deficient compounds of hydrogen refer to molecules that contain fewer electrons than the number of electrons required for a neutral molecule.

2. These molecules are unstable due to their electron deficiency and can form covalent bonds with other molecules to become stable.

3. Examples of such compounds include hydrides, hydrocarbons, and hydrogen halides.

4. Hydrides are compounds that contain hydrogen and one or more other elements.

5. Hydrocarbons are compounds that contain hydrogen and carbon atoms.

6. Hydrogen halides are compounds that contain hydrogen and one of the halogens, such as chlorine, bromine, or iodine.

Question:

Complete the following chemical reaction and classify into (a) hydrolysis, (b) redox and (c) hydration reactions.
Ca3N2(s)+H2O(l)→

Answer:

a) Hydrolysis reaction

Question:

Complete the following reactions: Zn(s)+NaOH(aq)heat

Answer:

1. Zn(s) reacts with NaOH(aq) to form Na2ZnO2(s) and liberate hydrogen gas: 2Zn(s) + 2NaOH(aq) → 2Na2ZnO2(s) + H2(g)

2. The reaction is exothermic and the heat generated helps to drive the reaction forward: 2Zn(s) + 2NaOH(aq) + heat → 2Na2ZnO2(s) + H2(g)

Question:

Discuss the consequence of high enthalpy of H-H bond in terms of chemical reactivity of dihydrogen.

Answer:

Step 1: Explain what an enthalpy is and how it relates to the H-H bond. Enthalpy is a measure of the total energy of a system, and the enthalpy of a chemical reaction is the difference between the total energy of the reactants and the total energy of the products. The H-H bond has a high enthalpy, meaning it requires more energy to break than other bonds.

Step 2: Explain how the high enthalpy of the H-H bond affects the chemical reactivity of dihydrogen. The high enthalpy of the H-H bond makes it difficult to break the bond and therefore makes dihydrogen less reactive. This means that it will take more energy to initiate a reaction involving dihydrogen, and the reaction may be slower than with other molecules. Additionally, the products of the reaction may also be different, as the high enthalpy of the bond can affect the chemical pathways taken.

Question:

How does the atomic hydrogen or oxy-hydrogen torch function for cutting and welding purposes? Explain.

Answer:

1. The atomic hydrogen or oxy-hydrogen torch is a type of welding torch that uses a combination of oxygen and hydrogen gases to create a flame that is hotter than a standard oxy-acetylene torch.

2. The torch produces a flame with a temperature of up to 4,500°C (8,132°F), which is hot enough to cut and weld metals such as steel, aluminum, and copper.

3. The torch works by combining the hydrogen and oxygen gases in a reaction chamber, where they are ignited by an electric spark.

4. The resulting flame is then directed through a nozzle and onto the metal to be cut or welded.

5. The heat from the flame melts the metal, allowing it to be cut or welded as needed.

6. The torch is used in a variety of industries, including automotive, aerospace, and manufacturing, and is a popular choice for welding and cutting due to its high temperature and efficiency.

Question:

Explain water-gas shift reaction in detail.

Answer:

Water-gas shift reaction (WGSR) is a chemical reaction between carbon monoxide (CO) and water (H2O) to form carbon dioxide (CO2) and hydrogen (H2). It is an important reaction in the production of hydrogen and synthesis gas from coal and other hydrocarbon fuels.

Step 1: The reaction begins when carbon monoxide and steam react over a catalyst such as iron oxide.

CO + H2O → CO2 + H2

Step 2: The reaction is exothermic, meaning that it releases heat. This heat helps to drive the reaction forward and increase the yield of the products.

Step 3: The reaction can be reversed if the temperature is increased. This is known as the reverse water-gas shift reaction, which produces carbon monoxide and hydrogen.

CO2 + H2 → CO + H2O

Step 4: The water-gas shift reaction is important in the production of hydrogen and synthesis gas from coal and other hydrocarbon fuels. It is also used in the production of methanol and other chemicals.

Question:

Arrange the following in order of increasing bond dissociation enthalpy. H−H, D−D and F−F

Answer:

1. H−H
2. D−D
3. F−F

Question:

What characteristics do you except from an electron-deficient hydride with respect to its structure and chemical reactions?

Answer:

Step 1: Understand what an electron-deficient hydride is. An electron-deficient hydride is a compound that has fewer electrons than normal, resulting in a higher than normal electron density.

Step 2: Consider the structure of an electron-deficient hydride. As the compound has fewer electrons than normal, it is likely to form strong covalent bonds, resulting in a more compact and stable structure.

Step 3: Think about the chemical reactions of an electron-deficient hydride. As the compound has an increased electron density, it is likely to be more reactive than normal and can form complex molecules more easily. It is also likely to be more prone to oxidation and reduction reactions.

Question:

Do you expect the carbon hydrides of the type (CnH2n+2) to act as Lewis acid or base? Justify your answer.

Answer:

Step 1: Carbon hydrides of the type (CnH2n+2) contain an uneven number of electrons, making them electron deficient and therefore Lewis acids.

Step 2: Lewis acids accept electron pairs from Lewis bases, making them electron donors. Therefore, carbon hydrides of the type (CnH2n+2) act as Lewis acids.

Step 3: To justify this answer, we can look at the chemical structure of the compound. As mentioned previously, carbon hydrides of the type (CnH2n+2) contain an uneven number of electrons, making them electron deficient. This electron deficiency makes them electron donors and therefore Lewis acids.

Question:

How do you expect the metallic hydrides to be useful for hydrogen storage? Explain.

Answer:

1. Metallic hydrides are compounds that contain hydrogen and a metal, such as sodium or magnesium.

2. These compounds are attractive for hydrogen storage as they have a high capacity for storing hydrogen.

3. Metallic hydrides can store hydrogen at relatively low pressures and temperatures, making them more practical than other hydrogen storage methods.

4. Furthermore, they are relatively safe to store and transport, as they are not flammable or explosive like compressed hydrogen gas.

5. Metallic hydrides can be used in fuel cell applications, as they can be used to store hydrogen and then release it when needed.

6. This makes them a viable option for powering electric vehicles, as they can provide a reliable source of hydrogen fuel.

7. Additionally, metallic hydrides can be used in a variety of industrial applications, such as in chemical synthesis and in the production of ammonia.

8. In conclusion, metallic hydrides are highly attractive for hydrogen storage due to their high capacity, safety, and versatility.

Question:

Write chemical reactions to show the amphoteric nature of water.

Answer:

1. Reaction of water with an acid: HCl (aq) + H2O (l) → H3O+ (aq) + Cl- (aq)

2. Reaction of water with a base: NaOH (aq) + H2O (l) → Na+ (aq) + OH- (aq) + H2O (l)

Question:

Write chemical reactions to justify that hydrogen peroxide can function as an oxidising as well as reducing agent.

Answer:

1. Oxidation of Hydrogen Peroxide: 2H2O2 (aq) → O2 (g) + 2H2O (l)

2. Reduction of Hydrogen Peroxide: 2H2O2 (aq) + 2e- → 2OH- (aq) + H2O (l)

Question:

Explain following terms. (i) Hydrogen economy (ii) Hydrogenation (iii) Syngas (iv) Water-gas shift reaction
(v) Fuel-cell

Answer:

(i) Hydrogen Economy: A hydrogen economy is an economy that is based on the use of hydrogen as an energy source. Hydrogen is used in fuel cells to generate electricity, and can also be used as a fuel for transportation and heating.

(ii) Hydrogenation: Hydrogenation is a chemical reaction that adds hydrogen atoms to an unsaturated compound, such as an oil or fat. This process is used to make products such as margarine and shortening.

(iii) Syngas: Syngas, or synthesis gas, is a mixture of carbon monoxide and hydrogen that is produced by the partial oxidation of a hydrocarbon fuel, such as natural gas or coal.

(iv) Water-gas shift reaction: The water-gas shift reaction is a chemical reaction in which carbon monoxide and water react to produce hydrogen and carbon dioxide. This reaction is used in fuel cells to produce hydrogen gas.

(v) Fuel Cell: A fuel cell is an electrochemical device that converts a fuel, such as hydrogen, into electrical energy. Fuel cells are used in a variety of applications, such as powering electric vehicles and providing backup power for buildings.

Question:

Write the names of isotopes of hydrogen. What is the mass ratio of these isotopes?

Answer:

Answer:

1. The names of isotopes of hydrogen are protium (1H), deuterium (2H), and tritium (3H).

2. The mass ratio of these isotopes is 1:2:3, with protium being the lightest, deuterium being twice as heavy, and tritium being three times as heavy.

Question:

Why does hydrogen occur in a diatomic form rather than in a monoatomic form under normal conditions?

Answer:

1. Hydrogen is the lightest and smallest element in the periodic table.
2. Its single electron is easily shared with other atoms, allowing it to form chemical bonds more easily than other elements.
3. Hydrogen’s electron is also more easily lost than other elements, making it more likely to form covalent bonds with other atoms.
4. Under normal conditions, this means that two hydrogen atoms will form a covalent bond to form a diatomic molecule, rather than staying as a single atom.

Question:

Complete the following reactions: C3H8(g)+3H2O(g)Δcatalyst

Answer:

1. C3H8(g)+3H2O(g) → 3CO2(g)+7H2(g) Δcatalyst

2. C3H8(g)+5O2(g) → 3CO2(g)+4H2O(g) Δcatalyst

Question:

Compare the structures of H2O and H2O2.

Answer:

1. Identify the chemical formulas of H2O and H2O2; H2O is composed of two hydrogen atoms and one oxygen atom, while H2O2 is composed of two hydrogen atoms and two oxygen atoms.

2. Examine the molecular structure of H2O and H2O2; H2O has a bent molecular structure, while H2O2 has a linear molecular structure.

3. Determine the polarity of H2O and H2O2; H2O is a polar molecule, while H2O2 is a non-polar molecule.

4. Analyze the bond angles of H2O and H2O2; H2O has a bond angle of 104.5 degrees, while H2O2 has a bond angle of 180 degrees.

5. Consider the boiling points of H2O and H2O2; H2O has a boiling point of 100°C, while H2O2 has a boiling point of 150°C.

Question:

Do you expect different products in solution when aluminium (III) chloride and potassium chloride treated separately with (i) normal water (ii) acidified water, and (iii) alkaline water? Write equations wherever necessary.

Answer:

(i) When aluminium (III) chloride is treated with normal water, it will form aluminium hydroxide and hydrochloric acid.

AlCl3 + 3H2O → Al(OH)3 + 3HCl

When potassium chloride is treated with normal water, it will form potassium hydroxide and hydrochloric acid.

KCl + H2O → KOH + HCl

(ii) When aluminium (III) chloride is treated with acidified water, it will form aluminium chloride and hydrochloric acid.

AlCl3 + HCl → AlCl2 + 2HCl

When potassium chloride is treated with acidified water, it will form potassium chloride and hydrochloric acid.

KCl + HCl → KCl + HCl

(iii) When aluminium (III) chloride is treated with alkaline water, it will form aluminium hydroxide and chlorine gas.

AlCl3 + 3OH- → Al(OH)3 + 3Cl-

When potassium chloride is treated with alkaline water, it will form potassium hydroxide and chlorine gas.

KCl + OH- → KOH + Cl-

Question:

Explain fuel-cell in detail.

Answer:

1. A fuel cell is an electrochemical energy conversion device that produces electricity by combining hydrogen and oxygen.

2. It works by using a catalyst to break down the hydrogen molecules into protons and electrons, then the protons pass through a membrane while the electrons travel through an external circuit, creating a flow of electricity.

3. The oxygen molecules react with the protons and electrons to form water, which is the only byproduct of the reaction.

4. Fuel cells are highly efficient, producing electricity with very little waste heat or pollutants. They can be used in a variety of applications, such as powering cars, providing backup power for homes, and providing electricity for remote locations.

5. Fuel cells are also becoming more popular as an alternative energy source, as they provide a clean, renewable source of energy.

Question:

What do you understand by electron rich compounds of hydrogen.

Answer:

1. Electron rich compounds of hydrogen refer to compounds that contain a large number of electrons in comparison to the number of hydrogen atoms.

2. These compounds are formed when hydrogen atoms form covalent bonds with other atoms, such as oxygen, nitrogen, chlorine, or sulfur.

3. The electrons in these compounds are shared between the atoms, creating a stable compound.

4. Examples of electron rich compounds of hydrogen include water (H2O), hydrogen peroxide (H2O2), and hydrochloric acid (HCl).

Question:

Justify the position of hydrogen in the periodic table on the basis of its electronic configuration.

Answer:

Step 1: Explain what the periodic table is and its purpose.

The periodic table is an arrangement of elements in order of their atomic number, which is the number of protons in the nucleus of an atom. It is used to classify and organize elements based on their chemical and physical properties.

Step 2: Explain the electronic configuration of hydrogen.

The electronic configuration of hydrogen is 1s1, which means that it has one electron in its outermost shell. This makes it the simplest and lightest element on the periodic table.

Step 3: Explain why hydrogen is positioned where it is on the periodic table.

Hydrogen is positioned at the top left corner of the periodic table because it has the lowest atomic number of all the elements. This is due to its electronic configuration, which is the simplest and lightest of all the elements. This position on the periodic table also reflects the fact that hydrogen is the most abundant element in the universe, making up around 75% of all matter.

Question:

Describe the bulk preparation of dihydrogen by electrolytic method. What is the role of an electrolyte in this process ?

Answer:

1. The bulk preparation of dihydrogen by electrolytic method involves passing an electric current through an acidic solution of water. This causes the water molecules to split into hydrogen and oxygen gas.

2. The electrolyte used in this process is an acid, such as sulfuric acid, which helps to conduct the electric current through the solution. It also helps to catalyze the reaction, making it more efficient.

3. The electrolyte helps to provide ions for the reaction, which helps to break the water molecules into hydrogen and oxygen. The hydrogen ions then react with the oxygen to form dihydrogen.

4. The electrolyte also helps to maintain the pH of the solution, which is important for the reaction to take place. If the pH is too high or too low, the reaction will not occur.

5. Finally, the electrolyte helps to reduce the energy required for the reaction to take place. This helps to make the process more efficient and cost-effective.

Question:

Describe the structure of the common form of ice.

Answer:

1. The common form of ice is known as hexagonal ice, which is composed of six-sided crystalline structures.

2. Each of these crystalline structures is composed of two interlocking hexagonal rings of oxygen atoms, with each oxygen atom bonded to four hydrogen atoms.

3. The oxygen atoms in the hexagonal rings are arranged in a regular pattern, with each oxygen atom being surrounded by four other oxygen atoms.

4. This regular pattern of oxygen atoms creates a lattice structure, with each oxygen atom being connected to its four nearest neighbors by hydrogen bonds.

5. The hydrogen bonds between the oxygen atoms are responsible for the strength and stability of the hexagonal ice crystals.

6. The hexagonal ice crystals can form in a variety of shapes and sizes, depending on the temperature and pressure conditions in which they are formed.

Question:

What causes the temporary and permanent hardness of water ?

Answer:

Step 1: Understand the question.

The question is asking what causes temporary and permanent hardness of water.

Step 2: Research the answer.

Temporary hardness of water is caused by the presence of calcium and magnesium bicarbonates in the water. Permanent hardness of water is caused by the presence of calcium and magnesium sulfates and chlorides in the water.

Question:

Discuss the principle and method of softening of hard water by synthetic ion-exchange resins.

Answer:

Step 1: Explain the Principle of Softening Hard Water: Hard water contains dissolved minerals such as calcium and magnesium, which can cause problems such as scaling in plumbing and appliances. Softening hard water involves removing these minerals through a process called ion exchange.

Step 2: Explain the Method of Softening Hard Water: The method of softening hard water involves passing the hard water through a bed of synthetic ion-exchange resins. These resins are negatively charged and attract the positively charged calcium and magnesium ions, exchanging them for sodium ions. The sodium ions are released into the water, leaving the hard water softened.

Step 3: Describe the Benefits of Softening Hard Water: Softening hard water has a number of benefits. It helps to prevent scaling in plumbing and appliances, and it also makes the water more pleasant to drink. It also helps to reduce the amount of soap and detergent needed for cleaning, as it is more effective in lathering.

Question:

What is meant by demineralised water and how can it be obtained?

Answer:

Demineralised water is water that has had its mineral content removed. It can be obtained by passing water through a reverse osmosis membrane, a process called reverse osmosis filtration, or by passing water through a bed of ion exchange resins, a process called ion exchange filtration. Both processes involve forcing water through a membrane or bed of resins, which traps the minerals and other impurities, leaving only pure water behind.

Question:

Do you expect different products in solution when aluminium (III) chloride and potassium chloride treated separately with (i) normal water (ii) acidified water, and (iii) alkaline water? Write equations wherever necessary.

Answer:

Answer:

(i) When aluminium (III) chloride is treated with normal water, the products formed are aluminium hydroxide and hydrochloric acid. The equation for this reaction is: AlCl3 + 3H2O → Al(OH)3 + 3HCl

(ii) When aluminium (III) chloride is treated with acidified water, the products formed are aluminium chloride and hydrochloric acid. The equation for this reaction is: AlCl3 + 3HCl → AlCl3 + 3HCl

(iii) When aluminium (III) chloride is treated with alkaline water, the products formed are aluminium hydroxide and chloride ions. The equation for this reaction is: AlCl3 + 3OH- → Al(OH)3 + 3Cl-

When potassium chloride is treated with normal water, the products formed are potassium hydroxide and chloride ions. The equation for this reaction is: KCl + H2O → KOH + Cl-

When potassium chloride is treated with acidified water, the products formed are potassium chloride and hydrogen ions. The equation for this reaction is: KCl + H+ → KCl + H+

When potassium chloride is treated with alkaline water, the products formed are potassium hydroxide and chloride ions. The equation for this reaction is: KCl + OH- → KOH + Cl-