Stoichiometry Word Problems
Translate words to balanced equations and ratios.
About this topic
Word problems combine all stoichiometry skills. A reliable approach is: write and balance the equation; list the given and wanted quantities; convert to moles; apply the mole ratio; check for a limiting reactant; convert to the requested units; and consider percent yield. Always check that the answer is sensible and has the right significant figures.
Reading carefully is the main challenge: identify the substance given and the one wanted, and notice words like excess, completely reacts, at STP, or percent yield. Draw a flow chart from given to wanted to plan the route. Mass goes through molar mass, solution through molarity times volume, gases through the gas law, and particles through Avogadro's number, and mole ratios are always the middle step.
Example: Calcium carbonate in limestone reacts with hydrochloric acid to give carbon dioxide. How many litres of gas at STP form from 25.0 g of CaCO3? Balanced: CaCO3 + 2HCl gives CaCl2 + H2O + CO2. Moles of CaCO3 = 25.0 / 100.09 = 0.250. The ratio is 1:1, so 0.250 mol CO2, which equals 5.60 L.
Stoichiometry is used to plan industrial production, fuel use, medicine doses and pollution control. Common errors include skipping the balancing step, mixing up grams and moles, and ignoring a limiting reactant. Practice by estimating the answer first.
Key ideas
- Write and balance
- List givens
- Convert through moles
Quick check
Use cases: where Stoichiometry Word Problems helps
- Homework: review the key idea behind Stoichiometry Word Problems before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Stoichiometry Word Problems without notes.
- Visual learning: play with the interactive lab to see how Stoichiometry Word Problems changes when you adjust its inputs.
- Teaching a friend: explain Stoichiometry Word Problems in your own words, then compare your version with the key ideas.
Chemistry explains medicine, food, cleaning products, fuels and building materials.
Frequently asked questions
What is Stoichiometry Word Problems?
Translate words to balanced equations and ratios.
What will I learn in Stoichiometry Word Problems?
Write and balance. List givens. Convert through moles.
Is Stoichiometry Word Problems part of Chemistry?
Yes. It is one of 150 Chemistry topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Stoichiometry Word Problems lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Stoichiometry Word Problems?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.