Question

Give the chemical formula and compute the ratio by mass of combining elements in Aluminium fluoride.

Answer 1

Chemical Formula:

1. The number of atoms in each element of a compound is determined by the chemical formula. It comprises symbols for the constituent atoms as well as subscripts for each element's number.
2. Aluminium fluoride is a colourless chemical that results from an ionic connection between aluminium and fluorine atoms..
3. Electronic configuration of aluminium$=1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^1$ and electronic configuration of Chlorine $=1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^5$
4. Fluoride contains seven valence electrons while aluminium has three. Because the p orbital will be filled when there are eight electrons, each electron from the aluminium outer shell is shared with a distinct fluoride atom.
5. So three fluorine atoms combine with aluminium to give ${\mathrm{AlF}}_3$ i.e. Aluminium fluoride.

Ratio by mass:

1. Ratio by mass is defined as the ratio of masses of the atom that a compound contains
2. Mass of Aluminum$=27$, the mass of fluorine $=19$
3. Since it contains three molecules of Fluorine, mass $=19\mathrm{x}3\Rightarrow 57$
4. Ratio by mass$=\mathrm{Al}:\mathrm{F}\Rightarrow 27:57\Rightarrow 9:19$