Hydrogen and its Properties Quiz
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Questions and Answers

What is the name of the element with the atomic number 1?

Hydrogen

Who discovered hydrogen?

Henry Cavendish

The name "hydrogenium" means "water-forming."

True (A)

What is the percentage of hydrogen in the universe?

<p>74%</p> Signup and view all the answers

What is the percentage of oxygen in the human body?

<p>65%</p> Signup and view all the answers

Which of the following are physical properties of hydrogen?

<p>colorless (B), tasteless (C), odorless (D), gaseous at room temperature (E)</p> Signup and view all the answers

What is the melting point of hydrogen in Kelvin?

<p>13.66</p> Signup and view all the answers

What is the density of hydrogen at 273 Kelvin in g/dm³?

<p>0.090</p> Signup and view all the answers

Hydrogen is soluble in some metals.

<p>True (A)</p> Signup and view all the answers

What are the two varieties of hydrogen?

<p>Ortho and para-hydrogen</p> Signup and view all the answers

What are the spin states of ortho-hydrogen molecules?

<p>parallel (B)</p> Signup and view all the answers

Under normal conditions, hydrogen contains 25% of the ortho variety and 75% of the para variety.

<p>False (B)</p> Signup and view all the answers

What happens to the percentage of para-hydrogen as it cools?

<p>increases (C)</p> Signup and view all the answers

Atomic hydrogen exists for a long time at room temperature.

<p>False (B)</p> Signup and view all the answers

What do atomic hydrogen atoms react with to form hydrides?

<p>Chlorine, bromine, iodine, oxygen, sulfur arsenic, and antimony</p> Signup and view all the answers

What does atomic hydrogen reduce silver nitrate (V) to?

<p>Silver</p> Signup and view all the answers

What does atomic hydrogen reduce chromates (VI) to?

<p>Chromium (III) salts</p> Signup and view all the answers

What does atomic hydrogen reduce potassium manganate (VII) to?

<p>Manganese (II) salts</p> Signup and view all the answers

What is active hydrogen?

<p>Hydrogen at the moment of its formation</p> Signup and view all the answers

What reaction produces active hydrogen?

<p>The reaction of zinc and hydrochloric acid</p> Signup and view all the answers

Active hydrogen has chemical properties similar to atomic hydrogen.

<p>True (A)</p> Signup and view all the answers

What are the three isotopes of hydrogen?

<p>Protium, deuterium, and tritium</p> Signup and view all the answers

Which isotope of hydrogen is most prevalent?

<p>Protium, with only one proton and no neutrons, is the most abundant isotope of hydrogen, making up approximately 99.985% of all naturally occurring hydrogen.</p> Signup and view all the answers

What is the isotopic mass of deuterium?

<p>2.0141</p> Signup and view all the answers

What is the name for tritium?

<p>Tritium, with one proton and two neutrons, is also known as superheavy hydrogen, radiohydrogen, or trace amount hydrogen, due to its heavier mass and radioactive nature.</p> Signup and view all the answers

Metallic hydrogen was obtained at a pressure of 1.0 Mbar.

<p>False (B)</p> Signup and view all the answers

What are the two types of water?

<p>Water and heavy water</p> Signup and view all the answers

Heavy water is a good moderator in nuclear reactors.

<p>True (A)</p> Signup and view all the answers

What is the main method for producing hydrogen?

<p>Steam reforming of natural gas</p> Signup and view all the answers

What are the other methods for producing hydrogen?

<p>Water electrolysis (A), Hydrogen production from biomass (B), Biological methods (C)</p> Signup and view all the answers

What is water gas?

<p>A mixture of hydrogen and carbon monoxide</p> Signup and view all the answers

What is the chemical equation for producing water gas?

<p>C + H₂O → H₂ + CO</p> Signup and view all the answers

What is steam-methane reforming?

<p>A process to produce hydrogen from methane</p> Signup and view all the answers

Steam-methane reforming is a clean process that doesn't emit any carbon dioxide.

<p>False (B)</p> Signup and view all the answers

What does a hydrogen-air fuel cell generate?

<p>Electricity and heat</p> Signup and view all the answers

What is the chemical equation for the overall reaction in a hydrogen-air fuel cell?

<p>2H2(g) + O2(g) → 2H₂O</p> Signup and view all the answers

What is the main aim of the DOE's H2@Scale initiative?

<p>To enable clean hydrogen use across different sectors</p> Signup and view all the answers

Why is hydrogen used in the production of margarine?

<p>To harden liquid oils</p> Signup and view all the answers

Hydrogen is used as fuel in rockets and space shuttles.

<p>True (A)</p> Signup and view all the answers

What is hydrogen used to produce?

<p>Ammonia</p> Signup and view all the answers

Hydrogen is used as an energy source in fuel cells.

<p>True (A)</p> Signup and view all the answers

The Hindenburg airship was powered by hydrogen.

<p>True (A)</p> Signup and view all the answers

Where is hydrogen positioned in the periodic table?

<p>Group 1 and 17</p> Signup and view all the answers

What are the similarities between hydrogen and alkali metals?

<p>One electron in the valence shell (B), Oxidation state +1 in compounds (C), Formation of compounds with nonmetals (D), Reducing properties (E)</p> Signup and view all the answers

What is the ionization energy of hydrogen in kJ/mol?

<p>1312</p> Signup and view all the answers

What are the four electronic processes involved in hydrogen chemistry?

<p>Loss of a valence electron to form an H+ ion (A), Addition of an electron to form an H- ion (B), Formation of a single covalent bond (C), Formation of hydrogen bonds (D)</p> Signup and view all the answers

Hydrogen is very stable under normal conditions.

<p>True (A)</p> Signup and view all the answers

Hydrogen is a good reducing agent.

<p>True (A)</p> Signup and view all the answers

Hydrogen reacts with oxygen to form water.

<p>True (A)</p> Signup and view all the answers

What are compounds of hydrogen with another element called?

<p>Hydrides</p> Signup and view all the answers

What is the general formula for hydrides?

<p>XH, XH₂, XH₃, XH₄, H3X, H4X2</p> Signup and view all the answers

What is the general name for hydrides of alkali metals?

<p>Alkali metal hydrides</p> Signup and view all the answers

What type of compound is methane?

<p>A neutral hydride</p> Signup and view all the answers

Acidic hydrides react with hydroxides to form salts.

<p>True (A)</p> Signup and view all the answers

What type of bonds do salt-type hydrides exhibit?

<p>Ionic bonds</p> Signup and view all the answers

What type of bonds do covalent hydrides exhibit?

<p>Covalent bonds</p> Signup and view all the answers

What is the name for hydrides formed by transition metals?

<p>Metallic hydrides</p> Signup and view all the answers

Hydrogen bonding occurs between two very electronegative atoms.

<p>True (A)</p> Signup and view all the answers

Hydrogen bonds are purely electrostatic.

<p>False (B)</p> Signup and view all the answers

Hydrogen bonding is important for the structure of DNA.

<p>True (A)</p> Signup and view all the answers

Hydrogen bonding influences the properties of alcohols and phenols.

<p>True (A)</p> Signup and view all the answers

Hydrogen bonding has no effect on the physical state of water.

<p>False (B)</p> Signup and view all the answers

Study Notes

Hydrogen and its Compounds

  • Hydrogen is element number 1 (H) on the periodic table, with an atomic mass of 1.00794.
  • The name "hydrogenium" means "water-forming" (A. Lavoisier).
  • Hydrogen was discovered in 1766 by Henry Cavendish.
  • Hydrogen liquefied in 1883 by Olszewski and Wróblewski.
  • Hydrogen liquefied in 1898 by the expansion method by Dewar.

Hydrogen in the Universe

  • Hydrogen (7500) makes up a significantly larger proportion of the universe than any other element.
  • 74% of the universe is hydrogen.
  • 25% of the universe is helium.

Hydrogen in the Human Body

  • A living cell comprises six elements: C, H, O, N, P, S.
  • These organogenic elements constitute about 97.9% of the human body's mass.
  • Oxygen (65%) is the most abundant element in the human body.
  • Carbon (18%) is the second most abundant element in the human body.
  • Hydrogen (9.5%) is the third most abundant element in the human body.

Physical Properties of Hydrogen

  • Colorless, odorless, tasteless gas.
  • Approximately 14 times lighter than air.
  • Very slightly soluble in water.
  • Soluble in some metals (e.g., palladium and platinum).
  • Melting point: 13.66 K
  • Boiling point: 20.13 K
  • Enthalpy of vaporization: 0.904 kJ/mol-1
  • Enthalpy of fusion: 0.117 kJ/mol-1
  • Density (273 K): 0.090 g/dm-3
  • Bond dissociation enthalpy: 435.99 kJ/mol-1
  • Interatomic distance: 74.14 pm
  • Standard entropy (298 K): 130.7 J/K mol-1

Ortho- and para-Hydrogen

  • Hydrogen exists in ortho and para varieties, distinguished by the direction of the nuclear spin.
  • Under normal conditions, hydrogen is about 75% ortho and 25% para.
  • As it cools, the proportion of para-hydrogen increases.
  • At 20 K, the para-hydrogen content reaches 99.7%.

Atomic Hydrogen

  • Atomic hydrogen exists for a very short time at room temperature.
  • It rapidly recombines.
  • It reacts with chlorine, bromine, iodine, oxygen, sulfur, arsenic, and antimony to form hydrides.
  • It reduces silver nitrate (V) to silver, chromates (VI) to chromium (III) salts, and potassium manganate (VII) to manganese (II) salts.

Active Hydrogen

  • Active hydrogen refers to the state of hydrogen formed in a reaction, such as zinc with hydrochloric acid.
  • This nascent hydrogen has highly reactive chemical properties like atomic hydrogen.
  • Active hydrogen reduces KMnO4.

Isotopes of Hydrogen

  • Protium (1H): 99.985% abundant light hydrogen.
  • Deuterium (2H, or D): 0.0156% abundant heavy hydrogen.
  • Tritium (3H, or T): Trace amounts, superheavy and radiohydrogen.

Water and Heavy Water

  • Difference in boiling points between water and heavy water indicates stronger hydrogen bonding in heavy water.
  • Deuterated compounds are used in solvents for NMR spectroscopy.
  • Heavy water (D2O) is a moderator in nuclear reactions, reducing neutron energies.

Methods of Producing Hydrogen

  • Steam reforming of natural gas is the primary method (approximately 95%).
  • Partial oxidation of methane.
  • Coal gasification.
  • Water electrolysis.
  • Hydrogen production from biomass.
  • Biological methods (fermentation, biophotocatalysis).

Obtaining Water Gas

  • Water gas (a mixture of hydrogen and carbon monoxide) is produced from steam and powdered coal or coke at around 1000°C in a fluidized reactor.

Obtaining Hydrogen from Water Gas

  • Stage 1: Catalytic conversion of carbon monoxide in water gas and water vapor at 200-300°C.
  • Stage 2: Elution of carbon dioxide under pressure using a hot potassium carbonate solution.
  • Stage 3: Final purification of residual CO and other gases.

Steam-Methane Reforming

  • Steam-methane reforming produces hydrogen from natural gas.
  • The reaction emits a considerable amount of CO2.

Hydrogen Sources

  • Sources include renewable electricity (solar, wind, hydropower) to split water.
  • Most hydrogen is currently produced from natural gas.

Water Electrolysis

  • Water electrolysis uses electricity to split water into hydrogen and oxygen.
  • Addition of a small amount of acid, base, or salt increases conductivity.
  • Electrical potential (voltage) required is about 1.229 V.

Hydrogen Production - Laboratory Methods (from acids)

  • Active metals (e.g., zinc) react with dilute hydrochloric or sulfuric acids to produce hydrogen gas.

Hydrogen Production - Laboratory Methods (from water)

  • Active metals (e.g., potassium, calcium) react with water to generate hydrogen gas.

Hydrogen Production - Laboratory Methods (from metal hydrides)

  • Metal hydrides (e.g., lithium hydride, calcium hydride) react with water to release hydrogen gas.

Hydrogen Production - Laboratory Methods (from amphoteric metals)

  • Amphoteric metals (e.g., aluminum) react with bases (e.g., sodium hydroxide) and water to produce hydrogen.

Advantages of Hydrogen as an Energy Source

  • Environmentally friendly technology.
  • Minimizes toxin emission into the natural environment.
  • Various methods allow for large-scale hydrogen production.

Hydrogen-Air Fuel Cell

  • A fuel cell where hydrogen and oxygen react electrochemically to produce electricity.

Targeted Sectors for Expanded Clean Hydrogen Use

  • Hydrogen can be used in several sectors like transportation, the production of synthetic fuels, ammonia, and fertilizers.

Use of Hydrogen

  • Hydrogen is used in margarine production, rocket fuels, and the production of hydrochloric acid.
  • Many industrial applications involve hydrogen for processes in the chemical, petrochemical, and steel industries.
  • It's used in welding torches.
  • It is used in production of synthetic ammonia for the manufacture of fertilizers.

Airships

  • Hydrogen's low density led to its use in airships (e.g., the Hindenburg).
  • The Hindenburg's catastrophic fire in 1937 damaged public perception of airships.
  • Airships are now used for tourist flights and advertising.

The Position of Hydrogen in the Periodic Table

  • Hydrogen exhibits similarities to alkali metals (group 1) due to having one electron in its valence shell.
  • Hydrogen also has similarities to halogens (group 17) as it can gain an electron to fill its valence shell.
  • Hydrogen's electronic configuration and properties cause its placement in the periodic table to be uncertain, as it can behave both like a metal and a nonmetal.

Hydrogen Properties

  • Exhibits unique chemical behaviors due to its single electron.
  • Can lose or gain an electron or form single covalent bonds.

Chemical Properties of Hydrogen

  • Stable at normal temperatures, but flammable in air and in the presence of gaseous chlorine.
  • Reacts with chlorine, forming hydrochloric acid.
  • Reacts with oxygen to produce water, often with a pale blue flame.
  • Mixtures with air, oxygen, and chlorine are explosive.

Chemical Properties of Hydrogen (Continued)

  • Reacts with oxygen without a catalyst at a high temperature (600°C).
  • Reacts with other nonmetals at elevated temperatures.
  • Reacts with alkali metals at elevated temperatures forming hydrides.

Hydrides (Naming and Production)

  • Hydrides are binary compounds with hydrogen, with various categories and properties.
  • Naming follows a consistent convention (e.g., sodium hydride).
  • Production can involve direct synthesis from an element with hydrogen (example, H2 + S to produce H2S).
  • Some are prepared through exchange reactions between hydrogen and other compounds.

Division of Hydrides

  • Hydrides are categorized by their behavior towards water, acids, and bases.
  • Classified as basic, neutral, or acidic, depending on the compound and the reactivity involved.
  • Further divided by the nature of the chemical bond involved, such as ionic, covalent, or metallic.

Acidic Hydrides

  • Hydrides of elements in groups 16 and 17 are acidic, dissolving in water to form oxygen-free acids.
  • Form salts when reacted with metal hydroxides.

Basic Hydrides

  • Alkali metal hydrides (e.g., sodium hydride) react with water to produce hydroxide and hydrogen gas.

Neutral Hydrides

  • Neutral hydrides (e.g., methane, silicon hydride) generally don't react strongly with water or basic solutions.

Division of Hydrides (Polarity)

  • Based on the partial charge of the hydrogen atom.
  • Compounds with hydrogen having a larger partial positive charge (acids), and those having a partial negative charge (basic).
  • Some hydrides exhibit behavior characteristic of both acidic and basic properties.

Division of Hydrides (Bond Nature)

  • Salt-type hydrides (ionic).
  • Covalent hydrides (molecular).
  • Metallic hydrides (interstitial).

Binary Compounds of Hydrogen

  • Compounds involving hydrogen and other elements, categorized by various types of bonds.

Hydrogen Bonding

  • Hydrogen forms bonds with strongly electronegative atoms (N, O, F).
  • Characterized as partial electrostatic and partial covalent bonds.
  • Influences properties of many compounds, including water.
  • Effects include reduced vapor pressure, increased boiling point, increased viscosity, a lower density in ice compared to liquid water and the dissolution of compounds.

Hydrogen Bonding Phenomena

  • Open structures of water and ice, DNA's double helix, and the alpha-helices of some proteins.

Hydrogen Bonds in Biological Macromolecules

  • Hydrogen bonds are essential in forming specific shapes for complex biological molecules (proteins, DNA).

Hydrogen Bonding Affects

  • Hydrogen bonding impacts the properties of water and other molecules, including vapor pressure, boiling point, viscosity, and solubility.

Influence of Hydrogen Bonds

  • Hydrogen bonds affect the melting point and boiling points of compounds containing them.
  • Compounds with stronger hydrogen bonding show higher boiling points.

Hydrogen Bonds in Alcohols and Phenols

  • Hydrogen bonds affect the properties of alcohols and phenols.

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Description

Test your knowledge about hydrogen, one of the most important elements in the universe. This quiz covers its discovery, physical properties, presence in the human body, and its abundance in the cosmos. Dive in to explore why hydrogen is essential to life and the universe.

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