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Question 19N.3.hl.TZ0.16a

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Date November 2019 Marks available [Maximum mark: 3] Reference code 19N.3.hl.TZ0.16a
Level hl Paper 3 Time zone TZ0
Command term Discuss Question number a Adapted from N/A
a.
[Maximum mark: 3]
19N.3.hl.TZ0.16a

Consider the following data for butane and pentane at STP.

(a)

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.