• N2 • CCl4 • SiO2
• AlCl3 • CaCl2 • LiBr
Which compounds are ionic and which are covalent?
please help
Thank you
To determine whether a compound is ionic or covalent, you need to understand the difference between these two types of chemical bonding.
Ionic compounds are formed when there is a transfer of electrons between atoms. Typically, an ionic compound consists of a metal cation and a nonmetal anion. The metal loses electrons, forming a positive charge, while the nonmetal accepts these electrons, forming a negative charge. The resulting electrostatic attraction between the positive and negative ions holds the compound together.
Covalent compounds, on the other hand, are formed when atoms share electrons. Covalent compounds consist of two or more nonmetals that share electrons to achieve a stable electron configuration. The bond between the atoms is formed by the overlapping of their atomic orbitals, creating a shared electron cloud.
Now, let's analyze the given compounds:
- N2: This is a covalent compound because nitrogen is a nonmetal and can form a covalent bond with another nitrogen atom by sharing electrons.
- CCl4: This is also a covalent compound since carbon is a nonmetal, and chlorine is also a nonmetal. The carbon atom forms covalent bonds with four chlorine atoms by sharing electrons.
- SiO2: This compound is covalent as well. Silicon is a nonmetal, and oxygen is also a nonmetal. The silicon atom shares its electrons with two oxygen atoms.
- AlCl3: This compound is ionic. Aluminum is a metal, and chlorine is a nonmetal. Aluminum loses three electrons to form a 3+ cation, while each chlorine atom accepts one electron to form a 1- anion. The resulting compound contains the Al3+ cation and three Cl- anions.
- CaCl2: This compound is also ionic. Calcium is a metal, and chlorine is a nonmetal. Calcium loses two electrons to form a 2+ cation, while each chlorine atom accepts one electron to form a 1- anion. The compound contains the Ca2+ cation and two Cl- anions.
- LiBr: This compound is ionic. Lithium is a metal, and bromine is a nonmetal. Lithium loses one electron to form a 1+ cation, while bromine accepts this electron to form a 1- anion. The compound contains the Li+ cation and Br- anion.
To summarize:
- N2, CCl4, and SiO2 are covalent compounds.
- AlCl3, CaCl2, and LiBr are ionic compounds.
Look up the electronegativity if each and subtract them A difference of 1.8 or so is the 50-50 mark between more ionic or more covalent with more ionic being > 1.8 or so and more covalent being <1.8 or so.
Generally, when a question is stated this way, (that is, it is all ionic or all covalent) you call it all or nothing.
For example; N2.
N is about 3.0. 3.0-3.0- = 0 so this is covalent.
CCl4. C is 2.5; H is 2.1; 2.5-2.1 = 0.4 so covalent. etc