Measure of covalent character versus ionic radius

Observed trend for Fig. 1: When you look at LiX, it has the highest ionic difference and electronegativity difference. Whereas you look at CsX, it has the lowest electronegativity and ionic difference. This means that when you increase ionic radii, it decreases electronegativity.

E V A L U A T I O N

Conclusion

RQ: Investigating the effects of ionic radii and charge difference in experimental and theoretical lattice enthalpy values.

1. As ionic radii difference increases, so does the percent difference. But for Li and Na halides, there was inaccuracy in the result because of the unperfect spherical shape of the ion.

2. My hypothesis was not supported as seen in Fig.2. As ionic character increases, the electronegativity also increases, resulting in a decrease in percent difference. This could be because the compounds selected are more ionic than covalent.

Sources of errors and Improvements

The errors when conducting this experiment was the calculator. The rho (π) to calculate the theoretical lattice enthalpy values was 0.35. This could lead to some inaccuracies.

Moreover, the online database Wired Chemist was missing RbX and CsX halides. This could be a possible improvement. I would like to also use many online databases to better perform this experiment. Furthermore, using a wider range of halogens would produce a more reliable percent difference for each alkali metal.

Possible Extensions

Possible extension for this experiment could be to use one type of metal halide, for example, using silver. It could still observe the ionic difference between theoretical and experimental. Also, using a metal element would give a better result because of its covalent character.