DP Chemistry (first assessment 2025)

Test builder »

Question 22M.2.SL.TZ2.d

Date	May 2022	Marks available	[Maximum mark: 2]	Reference code	22M.2.SL.TZ2.d
Level	SL	Paper	2	Time zone	TZ2
Command term	Describe	Question number	d	Adapted from	N/A

d.

[Maximum mark: 2]

22M.2.SL.TZ2.d

Describe two observations that indicate the reaction of lithium with water is exothermic.

[2]

Markscheme

Any two:

temperature of the water increases ✔

lithium melts ✔

pop sound is heard ✔

Accept “lithium/hydrogen catches fire”.

Do not accept “smoke is observed”.

Syllabus sections

Tools » Tool 1: Experimental techniques

Structure 1. Models of the particulate nature of matter » Structure 1.4—Counting particles by mass: The mole » Structure 1.4.4—The empirical formula of a compound gives the simplest ratio of atoms of each element present in that compound. The molecular formula gives the actual number of atoms of each element present in a molecule. Interconvert the percentage composition by mass and the empirical formula. Determine the molecular formula of a compound from its empirical formula and molar mass.