Hydrogen

Which of the following statements is correct? (i) Metallic hydrides are deficient of hydrogen. (ii) Metallic hydrides conduct heat and electricity. (iii) Ionic hydrides do not conduct electricity in solid-state. (iv) Ionic hydrides are very good conductors of electricity in solid-state.

Solution: Option (i), (ii) and (iii) are the answers. Metallic hydrides are hydrides that are not stoichiometric in nature. They are excellent conductors of heat and electricity. Ionic hydrides...

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Which of the following statements is correct? (i) Elements of group 15 form electron deficient hydrides. (ii) All elements of group 14 form electron precise hydrides. (iii) Electron precise hydrides have tetrahedral geometries. (iv) Electron rich hydrides can act as Lewis acids.

Solution: Option (ii) and (iii) are the answers. Inorganic electron-specific hydrides are those hydrides in which the exact quantity of electrons required to form a typical covalent bond is present....

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The hardness of water may be temporary or permanent. Permanent hardness is due to the presence of (i) Chlorides of Ca and Mg in water (ii) Sulphates of Ca and Mg in water (iii) Hydrogen carbonates of Ca and Mg in water (iv) Carbonates of alkali metals in water

Solution: Option (i) and (ii) are the answers. Permanent hardness is caused by the presence of soluble magnesium and calcium salts in the form of chorides and sulphates in the water, which causes...

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Some of the properties of water are described below. Which of them is/are not correct? (i) Water is known to be a universal solvent. (ii) Hydrogen bonding is present to a large extent in liquid water. (iii) There is no hydrogen bonding in the frozen state of water. (iv) Frozen water is heavier than liquid water.

Solution: Option (iii) and (iv) are the answers. In ice, there is a great deal of hydrogen bonding. Because of the empty spaces found in tetrahedrons generated by hydrogen bonding, ice is...

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Which of the following statement(s) is/are correct in the case of heavy water? (i) Heavy water is used as a moderator in a nuclear reactor. (ii) Heavy water is more effective as a solvent than ordinary water. (iii) Heavy water is more associated than ordinary water. (iv) Heavy water has a lower boiling point than ordinary water.

Solution: Option (i) and (iii) are the answers. Heavy water is a moderator in nuclear reactors. It has a greater boiling point than regular water. It is thus more associated than plain water....

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Dihydrogen can be prepared on a commercial scale by different methods. In its preparation by the action of steam on hydrocarbons, a mixture of CO and H2 gas is formed. It is known as ____________. (i) Water-gas (ii) Syngas (iii) Producer gas (d) Industrial gas

Solution: Option (i) and (ii) are the answers. It is used to produce hydrogen, carbon monoxide, and other products from hydrocarbons like natural gas. This is done in a reformer, which uses...

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Which of the following statements are not true for hydrogen? (i) It exists as a diatomic molecule. (ii) It has one electron in the outermost shell. (iii) It can lose an electron to form a cation which can freely exist (iv) It forms a large number of ionic compounds by losing an electron

Solution: Option (iii) and (iv) are the answers. Because hydrogen has only one electron in its outermost shell, it can form diatomic molecules by covalent bonding. Its high ionisation enthalpy...

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Which of the following reactions is an example of use of water gas in the synthesis of other compounds? (i) CH4 (g) + H2O (g) → (1270KNi) CO (g) + H2 (g) (ii) CO (g) + H2O (g) → (Catalyst673K) CO2 (g) + H2 (g) (iii) CnH2n+2 + nH2O (g) → (1270KNi) nCO + (2n+1) H2 (iv) CO (g) + 2H2 (g) Cobalt → (Catalyst) CH3OH (l)

Solution: Option (iv) is the answer. The mixture of carbon monoxide and hydrogen is referred to as water gas. The term "synthesis gas" or "syngas" refers to the mixture of carbon monoxide and...

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Which of the following reactions increases production of dihydrogen from synthesis gas?(i) CH4 (g) + H2O (g) →(1270K Ni)CO (g) + 3H2 (g) (ii) C (s) + H2O (g) → (1270K) CO (g) + H2 (g) (iii) CO (g) + H2O (g)→ (Catalyst 673K) CO2 (g) + H2 (g) (iv) C2H6 + 2H2O → (1270K Ni) 2CO + 5H2

Solution: Option (iii) is the answer. The synthesis of dihydrogen can be boosted by mixing syngas carbon monoxide with steam and using iron chromate as a catalyst....

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Rohan heard that instructions were given to the laboratory attendant to store a particular chemical i.e., keep it in the darkroom, add some urea in it, and keep it away from dust. This chemical acts as an oxidising as well as a reducing agent in both acidic and alkaline media. This chemical is important for use in the pollution control treatment of domestic and industrial effluents (i) Write the name of this compound. (ii) Explain why such precautions are taken for storing this chemical.

Answer: The compound hydrogen peroxide, which functions as both an oxidising and reducing agent in both acidic and alkaline conditions, is referred to as hydrogen peroxide. After coming into touch...

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When the first element of the periodic table is treated with dioxygen, it gives a compound whose solid-state floats on its liquid state. This compound can act as an acid as well as a base. What products will be formed when this compound undergoes authorisation?

Answer: The first element, hydrogen, interacts with dioxygen to make water. Water is amphoteric, meaning it is both acid and basic. Water's solid state is ice. Due to its decreased density, it...

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Consider the reactions (A) H2O2 + 2HI → I2 + 2H2O (B) HOCl + H2O2 → H3O++ Cl–+ O2 Which of the following statements is correct about H2O2 with reference to these reactions? Hydrogen peroxide is ________. (i) an oxidising agent in both (A) and (B) (ii) an oxidising agent in (A) and reducing agent in (B) (iii) a reducing agent in (A) and oxidising agent in (B) (iv) a reducing agent in both (A) and (B)

Solution: Option (ii) is the answer. (A) $H_2O_2 + 2HI → I_2 + 2H_2O$ Iodine undergoes oxidation, transitioning from the -1 oxidation state to the 0 oxidation state. As a result, H2O2 works as an...

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Why does H+ ion always get associated with other atoms or molecules? (i) Ionisation enthalpy of hydrogen resembles that of alkali metals. (ii) Its reactivity is similar to halogens. (iii) It resembles both alkali metals and halogens. (iv) Loss of an electron from hydrogen atom results in a nucleus of very small size as compared to other atoms or ions. Due to the small size, it cannot exist free.

Solution: Option (iv) is the answer. Hydrogen has one electron in its s orbital and like alkali metals, it can lose one electron from its outer shell. So hydrogen is like alkalis. Onions reacting...

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Hydrogen resembles halogens in many respects for which several factors are responsible. Of the following factors which one is most important in this respect? (i) Its tendency to lose an electron to form a cation. (ii) Its tendency to gain a single electron in its valence shell to attain stable electronic configuration. (iii) Its low negative electron gain enthalpy value. (iv) Its small size.

Solution: Option (ii) is the answer. Hydrogen, like halogens, prefers to gain an electron to achieve a stable noble gas structure. Hydrogen's electrical configuration is 1s. The electrical...

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