Chemistry · Grades 10–12
Titration data and stoichiometry
Use the balanced mole ratio and distinguish endpoint from equivalence.
Learn the idea
Equivalence
At equivalence, reacting amounts match the balanced reaction stoichiometry.
Endpoint
An observed signal estimates the endpoint and may not coincide exactly with equivalence.
Moles
Use n = cV with compatible units, then apply the reaction ratio.
Data
Repeated consistent results support precision, while calibration and method affect accuracy.
Worked examples
How many moles are in 25.0 mL of 0.100 mol/L titrant?
0.100 × 0.0250 = 0.00250 mol.
0.0025 mol
At equivalence, must acid and base volumes always be equal?
Equal reacted moles do not imply equal volumes.
No; concentration and stoichiometry also matter.
Check your understanding
A 1:1 reaction uses 0.004 mol titrant to react with 0.020 L analyte. Find analyte concentration.
Which best describes an endpoint?
- An exact mathematical identity for all indicators.
- An observed signal used to stop or interpret a titration.
- The time the label was printed.
An acid requires 2 mol OH⁻ per mole. If 0.006 mol OH⁻ reacts at equivalence, how many moles of acid reacted?
Answers and marking notes
Answers and marking notes
- 0.2 mol/L
The analyte amount is 0.004 mol; divide by 0.020 L.
- An observed signal used to stop or interpret a titration.
A color or instrument response is an observation that estimates equivalence.
- 0.003 mol
Divide the hydroxide amount by the 2:1 ratio.
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Independent educational review required. Grade bands are approximate; these are not officially aligned curricula.