is sulfur a hard or soft base

What is the difference between soft base and hard base?

Soft Lewis acids and bases are relatively large, polarizable atoms, ions, and molecules. Hard Lewis acids and bases are relatively small and less polarizable. In practice, soft acids prefer to associate with soft bases, and hard acids prefer to associate with hard bases.

What is hard and soft acid and base theory?

A note from Dr. Haas: Hard and Soft Acid and Base (HSAB) theory allows us to predict which acids and bases prefer to interact. Recall that Lewis acid-base theory can be applied to describe metal-ligand interactions. Metal ions are electron pair acceptors, and thus are Lewis Acids.

What is the difference between soft and hard lewis acids and bases?

Soft Lewis acids and bases are relatively large, polarizable atoms, ions, and molecules. Hard Lewis acids and bases are relatively small and less polarizable .

Why are soft acids and bases more covalent than soft bases?

* The electronegativities of soft acids and soft bases are almost same and hence have less ionic interactions. i.e., the interactions between them are more covalent.

Is sulfide a hard base?

Sulfides are the most common soft bases in geology, although the larger halides, like bromide and iodide, are also soft.

Is Sulfate a hard base?

Fluoride, carbonates, oxides, phosphates and sulfates are examples of hard bases.

Which element is soft base?

soft bases contain larger, relatively polarizable donor atoms (such as P, S, and Cl)....Hard and Soft Acids and Bases.AcidsBasessoftBF3, Al2Cl6, CO2, SO3Cu+, Ag+, Au+, Tl+, Hg22+H−Pd2+, Pt2+, Hg2+CN−, SCN−, I−, RS−GaCl3, GaBr3, GaI3CO, R2S5 more rows•Sep 16, 2020

How can you tell if an acid or base is soft or hard?

0:076:10Hard and Soft Acids and Bases | B.Sc Chemistry - YouTubeYouTubeStart of suggested clipEnd of suggested clipAnd now we are going to discuss. The concept of hard and soft acid. And bases. Let's begin with aMoreAnd now we are going to discuss. The concept of hard and soft acid. And bases. Let's begin with a classification classification of metal ions and ligands. The entire concept is based on this

Is sulfate acidic or basic?

weak baseSulfate ion is a very weak base, while HSO−4 is a fairly strong acid, with Ka=0.01. On the other hand, H2SO4 is a very strong acid. Because it is such a weak base, sulfate ion undergoes negligible hydrolysis in aqueous solution.

What is the pH of sulfate?

The pH of a saturated solution of calcium sulfate is 7.7, close to that of pure water.

Which is not a hard acid?

Cu+, Ag+ is not a hard acid. Explanation for the answer: Hard acids are the atoms with high charge with small size whereas hard bases and are electron pair donors. For example H+, Ca2+, Na+ etc.

Is Zinc soft or hard?

Zinc is a sift metal because of the stable electron configuration. The d orbitals of zinc are completely filled and they cannot form metallic bonds. This is the reason why zinc is a soft metal.

What is hardness and softness?

and in this sense hardness is a measure for resistance to deformation or change. Likewise a value of zero denotes maximum softness, where softness is defined as the reciprocal of hardness.

What is meant by hard and soft acids?

Hard acids are Lewis acids that are only weakly polarizable. Other things being approximately equal: hard acids react faster with hard bases and form stronger bonds with them. soft acids react faster with soft bases and form stronger bonds with them.

What are hard and soft acids and bases explain with examples?

Examples of Soft Acids: Cs+, Cu+, Au+, Pt2+, Hg+, BH3, Br2, I2, RO+, quinones. Hard bases have low electronegative and low polarizability. Examples of Soft Bases: H-, R-, CO, PR3, C6H6, SCN- Soft bases react more readily and form stable compounds and complexes with soft acids.

What are hard acids and hard bases give examples?

Hard Acids/Bases: Early transition metal ions in the 3d series tend to be hard Lewis acids. Hard bases are typically small anions and neutral molecules. Some examples of hard acids and bases include: H+, O2-, OH-, F-, Fe3+, and Al3+.

Which is the hard acid?

Hard acids are Lewis acids that are only weakly polarizable. Other things being approximately equal: hard acids react faster with hard bases and form stronger bonds with them. soft acids react faster with soft bases and form stronger bonds with them.

Which of the following is not a hard acid?

Cu+, Ag+ is not a hard acid. Explanation for the answer: Hard acids are the atoms with high charge with small size whereas hard bases and are electron pair donors. For example H+, Ca2+, Na+ etc.

Which is the most hard acid?

The world's strongest superacid is fluoroantimonic acid, HSbF6. It is formed by mixing hydrogen fluoride (HF) and antimony pentafluoride (SbF5).

Where does sulfur come from?

Sulfur is derived from the Latin word sulpur, which was Hellenized to sulphur in the erroneous belief that the Latin word came from Greek. This spelling was later reinterpreted as representing an /f/ sound and resulted in the spelling sulfur, which appears in Latin toward the end of the Classical period. The true Greek word for sulfur, θεῖον, is the source of the international chemical prefix thio-. In 12th-century Anglo-French, it was sulfre. In the 14th century, the erroneously Hellenized Latin -ph- was restored in Middle English sulphre. By the 15th century, both full Latin spelling variants sulfur and sulphur became common in English. The parallel f~ph spellings continued in Britain until the 19th century, when the word was standardized as sulphur. On the other hand, sulfur was the form chosen in the United States, whereas Canada uses both. The IUPAC adopted the spelling sulfur in 1990 or 1971, depending on the source cited, as did the Nomenclature Committee of the Royal Society of Chemistry in 1992, restoring the spelling sulfur to Britain. Oxford Dictionaries note that "in chemistry and other technical uses ... the -f- spelling is now the standard form for this and related words in British as well as US contexts, and is increasingly used in general contexts as well."

What are the two types of sulfur compounds?

Some of the main classes of sulfur-containing organic compounds include the following: 1 Thiols or mercaptans (so called because they capture mercury as chelators) are the sulfur analogs of alcohols; treatment of thiols with base gives thiolate ions. 2 Thioethers are the sulfur analogs of ethers. 3 Sulfonium ions have three groups attached to a cationic sulfur center. Dimethylsulfoniopropionate (DMSP) is one such compound, important in the marine organic sulfur cycle. 4 Sulfoxides and sulfones are thioethers with one and two oxygen atoms attached to the sulfur atom, respectively. The simplest sulfoxide, dimethyl sulfoxide, is a common solvent; a common sulfone is sulfolane. 5 Sulfonic acids are used in many detergents.

What is the most common type of industrial "curing" or hardening and strengthening of natural rubber?

In the most common type of industrial "curing" or hardening and strengthening of natural rubber, elemental sulfur is heated with the rubber to the point that chemical reactions form disulfide bridges between isoprene units of the polymer.

What are the elements that make up semiconductors?

The principal ores of copper, zinc, nickel, cobalt, molybdenum, and other metals are sulfides. These materials tend to be dark-colored semiconductors that are not readily attacked by water or even many acids. They are formed, both geochemically and in the laboratory, by the reaction of hydrogen sulfide with metal salts. The mineral galena (PbS) was the first demonstrated semiconductor and was used as a signal rectifier in the cat's whiskers of early crystal radios. The iron sulfide called pyrite, the so-called "fool's gold", has the formula FeS 2. Processing these ores, usually by roasting, is costly and environmentally hazardous. Sulfur corrodes many metals through tarnishing .

What is the ionization energy of sulfur?

Sulfur burns with a blue flame with formation of sulfur dioxide, which has a suffocating and irritating odor. Sulfur is insoluble in water but soluble in carbon disulfide and, to a lesser extent, in other nonpolar organic solvents, such as benzene and toluene. The first and second ionization energies of sulfur are 999.6 and 2252 kJ/mol, respectively. Despite such figures, the +2 oxidation state is rare, with +4 and +6 being more common. The fourth and sixth ionization energies are 4556 and 8495.8 kJ/mol, the magnitude of the figures caused by electron transfer between orbitals; these states are only stable with strong oxidants such as fluorine, oxygen, and chlorine. Sulfur reacts with nearly all other elements with the exception of the noble gases, even with the notoriously unreactive metal iridium (yielding iridium disulfide ). Some of those reactions need elevated temperatures.

What is the most common allotrope of sulfur?

Sulfur forms several polyatomic molecules. The best-known allotrope is octasulfur, cyclo-S 8. The point group of cyclo-S 8 is D 4d and its dipole moment is 0 D. Octasulfur is a soft, bright-yellow solid that is odorless, but impure samples have an odor similar to that of matches. It melts at 115.21 °C (239.38 °F), boils at 444.6 °C (832.3 °F) and sublimates easily. At 95.2 °C (203.4 °F), below its melting temperature, cyclo-octasulfur changes from α-octasulfur to the β- polymorph. The structure of the S 8 ring is virtually unchanged by this phase change, which affects the intermolecular interactions. Between its melting and boiling temperatures, octasulfur changes its allotrope again, turning from β-octasulfur to γ-sulfur, again accompanied by a lower density but increased viscosity due to the formation of polymers. At higher temperatures, the viscosity decreases as depolymerization occurs. Molten sulfur assumes a dark red color above 200 °C (392 °F). The density of sulfur is about 2 g/cm 3, depending on the allotrope; all of the stable allotropes are excellent electrical insulators.

How much sulfur is in the human body?

It is the eighth most abundant element in the human body by weight, about equal in abundance to potassium, and slightly greater than sodium and chlorine. A 70 kg (150 lb) human body contains about 140 grams of sulfur.

Hard and Soft bases Definition

The Hard bases are regarded to those chemical species which have smaller non-polar electron donor atom whereas soft bases are those which are easily polarizable and have bigger donor electron atom.

Overview of Hard And Soft Bases

Several classification studies were done to classify acid and bases. Chemists come up with their own explanations to classify any acid or base. The first concept was given by Arrhenius in which he explained that proton donors are acids and hydroxide donors are bases.

Hard and Soft bases concept

The Hard and Soft base concept can be explained on the behalf of the size and the polarizability of the electron donor atom. In a base, if the electronegative atom has smaller radius and has less polarizability due to this reason, the negatively charged electron cloud is concentrated to a small region and is considered as a hard base.

Hard and Soft Base Concept in Linking of Ambidentate Ligands

The Hard and Soft base concept in bonding of ambidentate ligands can be explained as follows: In case of thiocyanide ion, the bonding of the ligand with the central metal ion in coordination complex occurs through sulfur atom. Sulfur being a weak electronegative atom having expanded electron cloud in the vicinity and is easily polarized.

Applications of Hard and Soft Bases in Hydrogen Bonding

The explanation of extent of hydrogen bonding is a very good application of hard and soft acid base interaction occurring in such bonding. In case of hydrogen bonding, as hydrogen being an electropositive atom with smaller radius act as a hard acid.

Which acid is harder, sulfur or nitrogen?

The nitrogen tends to coordinate with harder acids such as Si, whereas the sulfur tends to coordinate with softer acids such as Pt

Which is larger, softacids or bases?

Softacids and bases are larger, with a more diffuse distribution of electrons.

What order do hard acids bond?

Hard acids bond in the order: F->Cl->Br->I-

Why is Li+ less soluble in water than other salts?

than the other salts, yet it is the least soluble in water. This is due to the strong hard acid (Li+)/hard base (F-) interaction.

What is the difference between Arrheniusacids and bases?

Arrheniusacids form hydronium ions in water, and bases form hydroxide ions. This definition assumes that water is the solvent.

Which acid tends to bind to hard bases?

Hard acids tend to bind to hard bases.

Which acid has a lower charge density?

Soft acids typically have lower charge density (lower ionic charge and greater ionic size). Their

How do hard acid and hard base bond?

The combination of hard acid and hard base occurs mainly through ionic bonding as in Mg (OH)2 (Mg2+ = hard acid, OH− = hard base) and that of soft acid and soft base takes place mainly by covalent bonding as in HgI2 (Hg2+ = soft acid, I− = soft base.)

Which acid prefers to combine with a hard Lewis base?

This principle states that a hard Lewis acid prefers to combine with a hard Lewis base and similarly a soft Lewis acid prefers to combine with a soft Lewis base, since this type of combination gives a more stable product.

Which principle can explain the occurrence of some metals in nature as their ores?

The occurrence of some metals in nature as their ores can be explained with the help of HSAB principle.

Which scientist pointed out that hard solvents tend to dissolve hard solutes and vice versa?

7. Jorginsen has also pointed that hard solvents tend to dissolve hard solutes and vice versa.

Which scientist classified Lewis acids and Lewis bases as hard and soft acids and bases?

R.G. Pearson (1963) has classified the Lewis acids and Lewis bases as hard and soft acids and bases.

Is NH3 a hard or soft ligand?

in [Co (NH3)­5I]2+ (II) NH3 is a hard ligand and I− ion is a soft ligand, therefore (I) is a stable complex ion while (II) is unstable.

Is BH3 a base or a base?

Similarly since BH3 is soft acid and H− ion is a soft base, their combination gives a stable BH4− ion.

What is the difference between hard and soft acids?

According to HSAB concept, hard acids prefer binding to the hard bases to give ionic complexes, whereas the soft acids prefer binding to soft bases to give covalent complexes. It is sometimes referred to as Hard-Soft Interaction Principle (HSIP).

Which acid can be precipitated as a sulfide?

The softer acids like Ag +, Hg +, Hg 2+ etc., and borderline acids like Fe 2+, Ni 2+, Cu 2+, Zn 2+, Pb 2+ etc., can be precipitated as sulfides from their aqueous solutions since S 2- ion is a softer base. Following table illustrates the separation of cations based on their hardness or softness.

What metals prefer to bind with hard anions?

Whereas, the soft metals prefer to bind with soft anions and hence are found in nature as sulfides or phosphides or selenides.

What are the characteristics of a hard Lewis acid?

Hard Lewis acids are characterized by small ionic radii, high positive charge, strongly solvated, empty orbitals in the valence shell and with high energy LUMOs.

Where are F block elements found?

The f-block elements are found in nature as silicate minerals since the trivalent lanthanides are actinides are hard acids and tend to bind with hard oxygen bases as in silicates.

Which Lewis acids have intermediate properties?

The Borderline Lewis acids and bases have intermediate properties.

Is Fe 2+ a hard acid?

Reason: Fe 2+ is a borderline acid and is S-bound. Whereas Cr 3+ is hard acid and prefers to be N-bound.

Overview

Characteristics

Compounds

History

Production

Applications

Biological role

Precautions