Successive Ionisation Energies Questions
Worksheet
Successive Ionisation Energies
Consider the table of ionisation energies below (kJ mol-1).
| Element | 1st | 2nd | 3rd | 4th | 5th | 6th | 7th | 8th |
|---|---|---|---|---|---|---|---|---|
| V | 1314 | 3388 | 5300 | 7469 | 10989 | 13326 | 71330 | 84078 |
| W | 496 | 4562 | 6910 | 9543 | 13354 | 16613 | 20117 | 25496 |
| X | 1000 | 2252 | 3357 | 4556 | 7004 | 8495 | 27107 | 31719 |
| Y | 590 | 1145 | 4912 | 6491 | 8153 | 10496 | 12270 | 14206 |
| Z | 1251 | 2298 | 3822 | 5159 | 6542 | 9362 | 11018 | 33604 |
The elements V, W, X, Y and Z are Ca, Cl, S, O and Na. Suggest which one is which and justify your choice.
Answer
- V: There is a large jump between the 6th and 7th ionisation energies. It must be either oxygen or sulfur.
- W: There is a large jump between the 1st and 2nd ionisation energies. It must be sodium.
- X: There is a large jump between the 6th and 7th ionisation energies. It must be either oxygen or sulfur.
- Y: There is a large jump between the 2nd and 3rd ionisation energies. It must be Ca.
- Z: There is a large jump between the 7th and 8th ionisation energies. It must be chlorine.
- V vs X: V has to be oxygen and X has to be sulfur. V has much higher ionisation energies so it must higher up the group. V is oxygen and X is sulfur.
Graphs can be used to represent successive ionisation energies.
- Sketch a graph of the first eight ionisation energies of aluminium.
- Label the graph with the subshell that each electron is removed from.
Answer
