DP Chemistry (last assessment 2024)
Question 19N.3.hl.TZ0.a
Date | November 2019 | Marks available | [Maximum mark: 3] | Reference code | 19N.3.hl.TZ0.a |
Level | hl | Paper | 3 | Time zone | TZ0 |
Command term | Discuss | Question number | a | Adapted from | N/A |
a.
[Maximum mark: 3]
19N.3.hl.TZ0.a
Consider the following data for butane and pentane at STP.
Discuss the data.
[3]
Markscheme
«similar specific energy and» pentane has «much» larger energy density ✔
Any two for [2 max]:
similar number of bonds/«C and H» atoms in 1 kg «leading to similar specific energy»
OR
only one carbon difference in structure «leading to similar specific energy» ✔
NOTE: Accept “both are alkanes” for M2.
pentane is a liquid AND butane is a gas «at STP» ✔
NOTE: Accept “pentane would be easier to transport”.
1 m3 of pentane contains greater amount/mass than 1 m3 of butane ✔
NOTE: Accept “same volume” for “1 m3” and “more moles” for “greater amount” for M4.
