Explain in detail, which of the following pairs would have a higher melting point NH3 or P4
Don't you recognize that NH3 is a gas at room T and P is a solid at room T?
my teacher wants me to use the characteristics of aggregrate i know that NH3 is a polar molecular and i think P4 is a network aggregrate and i to use this information to answer this question?
Sara: you miss DrBob's point. If one is a gas at room temp, and the other solid, then the solid has to have a higher melting point. Somehow there must be a great divide here on this question.
To determine which of the following pairs would have a higher melting point, NH3 or P4, we need to consider the structure and bonding of the compounds.
1. NH3 (Ammonia):
NH3 is a molecular compound composed of one nitrogen (N) atom and three hydrogen (H) atoms. It adopts a pyramidal shape with the nitrogen atom at the center and the three hydrogen atoms forming a trigonal pyramid around it. The nitrogen atom forms covalent bonds with the three hydrogen atoms by sharing electrons.
2. P4 (Phosphorus):
P4 is a molecular compound composed of four phosphorus (P) atoms. It forms a tetrahedral structure with each phosphorus atom bonded to the other three phosphorus atoms through covalent bonds. The electrons are shared among the phosphorus atoms.
Now, to determine the melting point, we need to consider the strength of the intermolecular forces present in these compounds. The intermolecular forces are responsible for holding molecules together and need to be overcome in order for a substance to melt.
In NH3, the main intermolecular force is hydrogen bonding. Hydrogen bonding occurs when a highly electronegative atom (such as nitrogen in this case) is bonded to a hydrogen atom. The hydrogen atom becomes partially positive, and this positive charge can be attracted to a highly electronegative atom in another molecule (such as nitrogen in another NH3 molecule). Hydrogen bonding is relatively strong compared to other intermolecular forces.
In P4, the main intermolecular forces are London dispersion forces (also known as van der Waals forces). These forces occur due to temporary shifts in electron distribution within the molecule, leading to temporary dipoles. These temporary dipoles can induce dipoles in adjacent molecules and create attractive forces. London dispersion forces are generally weaker than hydrogen bonding.
Considering the above information, NH3 is expected to have a higher melting point than P4. This is because hydrogen bonding is stronger than London dispersion forces. The presence of hydrogen bonding in NH3 leads to a greater attraction between molecules, requiring more energy to break those bonds and melt the compound.
In summary, NH3 is expected to have a higher melting point than P4 due to the stronger intermolecular hydrogen bonding present in NH3.