Grams (Mass) Examples in Chemistry
Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of Grams (Mass).
This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in Chemistry.
Concept Recap
Grams are the base unit of mass in the metric system, measuring the quantity of matter in a substance. In chemistry, grams are the measurable quantity on a balance, but must be converted to moles for stoichiometric calculations using molar mass.
Grams tell you how heavy something is. A paperclip is about 1 gram. Moles tell you how many particles you have—a completely different question.
Read the full concept explanation →How to Use These Examples
- Read the first worked example with the solution open so the structure is clear.
- Try the practice problems before revealing each solution.
- Use the related concepts and background knowledge badges if you feel stuck.
What to Focus On
Core idea: Grams measure mass (how much stuff). Moles count particles (how many). You need molar mass to convert between them.
Common stuck point: Students try to use grams in mole ratios, forgetting that stoichiometry works with particle counts, not masses.
Sense of Study hint: When a problem gives you grams and asks about a reaction, convert to moles first. First find the molar mass of the substance from the periodic table. Then divide the given mass by the molar mass: n = m / M. Finally, use the mole value in your stoichiometric ratios.
Worked Examples
Example 1
easySolution
- 1 Use the relationship: mass (g) = moles × molar mass.
- 2 m = 2.50\,\text{mol} \times 58.44\,\text{g/mol}.
- 3 m = 146.1\,\text{g}.
Answer
Example 2
mediumPractice Problems
Try these problems on your own first, then open the solution to compare your method.