- #1
touma
- 18
- 0
How do I determine or predict if a substance is molecular or ionic?
PLEASE HELP! Thanks!
PLEASE HELP! Thanks!
Determine/Predict if Substance is Ionic or Molecular
In summary, molecules are made up of atoms that are held together by weak intermolecular forces, while ionic compounds are composed of metal and non-metal elements that form ionic bonds.
- #2
3trQN
- 337
- 1
Ill try and define some terms.
Molecule:
A chemical or chemical element that consists of more than one Atom bound together.
Compound:
A molecule consisting of a mixture of various different atoms or elements or a larger scale structure formed by multiple combined (chemically bonded) molecules.
Ion:
An atom which has a non-neutral charge is called an Ion, they can be positive or negative Ions called Cations and Anions respectivley.
Ionic:
Refering to a chemical compound (molecule) which consists of atoms that have non-neutral charges. Bonding (thats a model explaining the forces that hold atoms together) in ionic compounds is the result of the attraction between charges ( positive and negative ).
Molecular:
Having the property of a molecule.
(a good dictionary should explain these)
As you can see, Ionic can have the same meaning as molecule, but the converse is not allways so. Some molecules have no Ions in them. It can also be said that in some phases Ionic substances become completeley separated ( disassociated ) like in solutions or plasmas.
Molecule:
A chemical or chemical element that consists of more than one Atom bound together.
Compound:
A molecule consisting of a mixture of various different atoms or elements or a larger scale structure formed by multiple combined (chemically bonded) molecules.
Ion:
An atom which has a non-neutral charge is called an Ion, they can be positive or negative Ions called Cations and Anions respectivley.
Ionic:
Refering to a chemical compound (molecule) which consists of atoms that have non-neutral charges. Bonding (thats a model explaining the forces that hold atoms together) in ionic compounds is the result of the attraction between charges ( positive and negative ).
Molecular:
Having the property of a molecule.
(a good dictionary should explain these)
As you can see, Ionic can have the same meaning as molecule, but the converse is not allways so. Some molecules have no Ions in them. It can also be said that in some phases Ionic substances become completeley separated ( disassociated ) like in solutions or plasmas.
- #3
ksinclair13
- 99
- 0
Generally, ionic compounds are composed of a metal cation (positive charge) and a nonmetal anion (negative charge). An example is NaCl, which is made up of one Na+ ion and one Cl- ion. Molecular compounds are usually composed of two nonmetals (like CO2).
- #4
PPonte
Normally, ionic compounds in aqueous solution dissociate into a cation (positively charged ion) and an anion (negatively charged ion). That's the example of NaCl, mentioned by ksinclair13 and I can give another example as NaHO which dissociates into Na+ and HO- in aqueous solution.
A molecular substance does not dissociate in aqueous solution, I think.
A molecular substance does not dissociate in aqueous solution, I think.
- #5
bomba923
- 763
- 0
Bonding should clarify this query 
-Molecular solids are usually held together by (weak) intermolecular forces as hydrogens bonds, dipole-dipole interactions, and dispersion forces. Sucrose (C12H22O11), for example, is a molecular solid, whose strongest intermolecular forces are hydrogen bonds, followed by dipole-dipole interactions, and general dispersion forces.
-Ionic solids are held together via ionic bonds, often between cations and anions. NaCl is a lattice of sodium cations and chlorine anions held together by ionic bonds (strong electrostatic attractions between ions of opposite charge).
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*Just aside:
-Network solids are substances held together by strong directional covalent bonds (thus as structural networks of the similar molecules) Usual examples include diamond (held together strong covalent bonds between tetrahedral arrangement of carbods), graphite (layers of sp2-hybridized carbon networks), and quartz (crystalline arrangement of SiO2 molecules held together by covalent bonds with the oxygen atins).
-Molecular solids are usually held together by (weak) intermolecular forces as hydrogens bonds, dipole-dipole interactions, and dispersion forces. Sucrose (C12H22O11), for example, is a molecular solid, whose strongest intermolecular forces are hydrogen bonds, followed by dipole-dipole interactions, and general dispersion forces.
-Ionic solids are held together via ionic bonds, often between cations and anions. NaCl is a lattice of sodium cations and chlorine anions held together by ionic bonds (strong electrostatic attractions between ions of opposite charge).
------------------------------------
*Just aside:
-Network solids are substances held together by strong directional covalent bonds (thus as structural networks of the similar molecules) Usual examples include diamond (held together strong covalent bonds between tetrahedral arrangement of carbods), graphite (layers of sp2-hybridized carbon networks), and quartz (crystalline arrangement of SiO2 molecules held together by covalent bonds with the oxygen atins).
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- #6
wScott
- 88
- 0
A definition I learned in science yesterday was that ionic compounds are composed of metal and non-matal elements, molecular compounts, also called covalent compounds, are comprised of two or more non-metals.
Pretty much the same thing ksinclair13 said, just without the cool words :p
But listen to ksinclair13, he's helepd me out once ;)
Pretty much the same thing ksinclair13 said, just without the cool words :p
But listen to ksinclair13, he's helepd me out once ;)
- #7
ksinclair13
- 99
- 0
Actually, it would be wiser to listen to what others have to say because I am very inexperienced. Currently, I'm merely an AP student.
Hey wScott :-)
Hey wScott :-)
- #8
bomba923
- 763
- 0
ksinclair13 said:
Me too
FAQ: Determine/Predict if Substance is Ionic or Molecular
1. What is the difference between an ionic and molecular substance?
An ionic substance is made up of positively and negatively charged ions that are held together by electrostatic forces, while a molecular substance is made up of covalently bonded atoms that share electrons.
2. How can I determine if a substance is ionic or molecular?
One way to determine this is by looking at the chemical formula. If the formula contains a metal and a nonmetal, it is likely ionic. If it contains only nonmetals, it is likely molecular. However, this is not always the case, so further testing may be needed.
3. Can a substance be both ionic and molecular?
No, a substance can only be one or the other. However, some substances can exist in multiple forms, such as solid, liquid, or gas, depending on the conditions, and each form may have a different ionic or molecular structure.
4. What properties can help identify if a substance is ionic or molecular?
Ionic substances tend to have high melting and boiling points, conduct electricity in solution, and form crystal structures. Molecular substances, on the other hand, have lower melting and boiling points, do not conduct electricity in solution, and may exist as gases or liquids at room temperature.
5. Why is it important to know if a substance is ionic or molecular?
Knowing the structure of a substance can help predict its properties and behavior. For example, ionic substances are often more soluble in water and have stronger bonds, while molecular substances may be more flammable and have weaker bonds. This information can be useful in various fields, such as chemistry, medicine, and materials science.