Characteristics of Covalent (Molecular) compound

COVALENT and also IONIC COMPOUNDS

What elements make covalent bonds? Covalent bonds form when 2 or an ext nonmetals combine. Because that example, both hydrogen and also oxygen are nonmetals, and also when they combine to make water, they carry out so by creating covalent bonds. Compound that are composed of just non-metals or semi-metals v non-metals will display screen covalent bonding and will be classified as molecular compounds.

You are watching: Write the names of the following covalent compounds

As a general dominance of thumb, compounds the involve a metal binding through either a non-metal or a semi-metal will display screen ionic bonding. Thus, the compound formed from sodium and chlorine will be ionic (a metal and a non-metal). Nitrogen monoxide (NO) will certainly be a covalently tied molecule (two non-metals), silicon dioxide (SiO2) will certainly be a covalently bound molecule (a semi-metal and also a non-metal) and also MgCl2 will be ionic (a metal and a non-metal).

A polyatomic ion is an ion composed of 2 or an ext atoms that have actually a fee as a group (poly = many). The ammonium ion (see number below) consists of one nitrogen atom and also four hydrogen atoms. Together, they consist of a solitary ion with a 1+ charge and also a formula the NH4+. The carbonate ion (see number below) is composed of one carbon atom and three oxygen atoms and also carries an all at once charge that 2−. The formula that the carbonate ion is CO32−.

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The atom of a polyatomic ion space tightly bonded together and also so the entire ion behaves as a solitary unit. Several instances are uncovered in Table 3.3.1. Nonmetal atom in polyatomic ions room joined by covalent bonds, however the ion as a whole participates in ionic bonding. For example, ammonium chloride (NH4Cl) has actually ionic bonding in between a polyatomic ion, \(\ceNH_4^+\), and also \(\ceCl^−\) ions, yet within the ammonium ion (NH4+), the nitrogen and hydrogen atom are associated by covalent bond (shown above).

Both ionic and covalent bonding are additionally found in calcium carbonate. Calcium carbonate (CaCO3) has ionic bonding between calcium ion \(\ceCa^2+\) and also a polyatomic ion, \(\ceCO_3^2-\), yet within the carbonate ion (CO32-), the carbon and oxygen atom are connected by covalent bond (shown above).


Characteristics that Covalent (Molecular) Compounds

Compounds the contain covalent bonds (also referred to as molecular compounds) exhibit various physical properties 보다 ionic compounds. Because the attraction in between molecules, which are electrically neutral, is weaker than that between electrically fee ions, covalent compounds normally have much reduced melting and boiling points than ionic compounds (discussed in section 3.6). For example, water (molecular compound) boils at 100 °C while sodium chloride (ionic compound) boils in ~ 1413 °C. In fact, countless covalent compounds are liquids or gases at room temperature, and, in your solid states, castle are typically much softer than ionic solids. Furthermore, whereas ionic link are an excellent conductors of electrical energy when liquified in water, many covalent compounds, gift electrically neutral, are negative conductors of power in any state. The attraction between molecules (called intermolecular forces) will be debated in an ext detail in section 8.1



Exercise \(\PageIndex1\)

Is each compound are formed from ionic bonds, covalent bonds, or both?

\(\ceBa(OH)_2\) \(\ceF_2\) \(\cePCl_3\) Answer a:

both

Answer b:

covalent

Answer c:

covalent


MOLECULAR FORMULAS

The centregalilee.comical formulas because that covalent compounds are described as molecular formulas since these link exist as separate, discrete molecules. Typically, a molecular formula begins with the nonmetal the is closest to the lower left edge of the regular table, except that hydrogen is practically never written very first (H2O is the prominent exception). Climate the other nonmetal symbols space listed. Numerical subscripts are provided if there is much more than among a details atom. Because that example, us have currently seen CH4, the molecular formula for methane. Below is the molecule formula the ammonia, NH3.

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NAMING COVALENT COMPOUNDS

Naming binary (two-element) covalent compounds is comparable to naming straightforward ionic compounds. The very first element in the formula is simply detailed using the surname of the element. The 2nd element is named by acquisition the stem of the element name and including the suffix -ide. A system of number prefixes is offered to specify the number of atoms in a molecule. Table \(\PageIndex1\) lists these numerical prefixes. Normally, no prefix is added to the very first element’s name if over there is just one atom the the very first element in a molecule. If the second element is oxygen, the trailing vowel is typically omitted from the end of a polysyllabic prefix but not a monosyllabic one (that is, we would certainly say “monoxide” rather than “monooxide” and also “trioxide” rather than “troxide”).

Table \(\PageIndex1\): number Prefixes for Naming Binary Covalent compound Number of atoms in CompoundPrefix on the surname of the Element *This prefix is not supplied for the first element’s name.
1 mono-*
2 di-
3 tri-
4 tetra-
5 penta-
6 hexa-
7 hepta-
8 octa-
9 nona-
10 deca-

Let us exercise by specify name the link whose molecular formula is CCl4. The name begins with the name of the first element—carbon. The second element, chlorine, i do not care chloride, and also we affix the correct numerical prefix (“tetra-”) to suggest that the molecule has four chlorine atoms. Putting these piece together gives the surname carbon tetrachloride for this compound.





Example \(\PageIndex3\)

Write the name for every compound.

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BrF5 S2F2 CO

Solution

bromine pentafluoride disulfur difluoride carbon monoxide

For some an easy covalent compounds, us use typical names fairly than organized names. Us have already encountered this compounds, yet we perform them right here explicitly:

H2O: water NH3: ammonia CH4: methane

Methane is the simplest organic compound. Essential compounds space compounds through carbon atoms and also are called by a different nomenclature mechanism that we will present in section 4.6.