DP Chemistry (last assessment 2024)
Question 18M.2.sl.TZ2.b.i
| Date | May 2018 | Marks available | [Maximum mark: 1] | Reference code | 18M.2.sl.TZ2.b.i |
| Level | sl | Paper | 2 | Time zone | TZ2 |
| Command term | Outline | Question number | b.i | Adapted from | N/A |
b.i.
[Maximum mark: 1]
18M.2.sl.TZ2.b.i
Enthalpy changes depend on the number and type of bonds broken and formed.
The table lists the standard enthalpies of formation, , for some of the species in the reaction above.
Outline why no value is listed for H2(g).
[1]
Markscheme
for any element = 0 «by definition»
OR
no energy required to form an element «in its stable form» from itself
[1 mark]
