In IB Chemistry, concentration appears across stoichiometry, acids and bases, titrations, equilibrium, and even redox topics. Although the calculations themselves are usually straightforward, many students lose marks because they don’t remember the correct units or when to use them. This guide breaks down everything you need to know about concentration units in an IB-friendly format.
Quick Start Checklist
The primary concentration unit in IB Chemistry is:
- mol dm⁻³ (moles per cubic decimeter)
You may also see:
- g dm⁻³ (grams per cubic decimeter)
- % concentration (percentage by mass or volume)
- ppm (parts per million)
- mol L⁻¹ (used interchangeably with mol dm⁻³ in some contexts)
But mol dm⁻³ is the standard for stoichiometry, titrations, and equilibria.
Strengthening your general chemistry skills—especially lab accuracy—helps when working with concentration calculations:
https://www.revisiondojo.com/blog/tips-to-improve-your-lab-skills-for-ib-chemistry
Why IB Chemistry Uses mol dm⁻³
1. Direct link to moles
Since moles are the foundation of most quantitative chemistry, expressing concentration as moles per volume makes calculations fast and consistent.
2. Works seamlessly with common formulas
Many essential IB formulas use molarity directly:
- n = c × V for solutions
- Kc expressions
- Titration calculations
