🔍 Key Concepts

• neutralization number in lubricating oil analysis • relationship between acidity/alkalinity and neutralization number (TAN/TBN) • how changes in oil chemistry affect corrosion and wear, not necessarily viscosity, foaming, or water-separating properties

💭 Think About

• What does a neutralization number actually measure in an oil sample—thickness, tendency to foam, ability to separate from water, or amount of acid/base present? • If the neutralization number goes UP, does that mean you need more or less base (alkali) to neutralize the oil? What does that say about the oil’s acidity? • Which of the choices directly relates to chemical reactivity, as opposed to physical characteristics like viscosity or foaming tendency?

✅ Before You Answer

• Verify that neutralization number is tied to the amount of acid (or base reserve) in the oil, not to its thickness. • Check which listed properties (viscosity, demulsibility, foaming, acidity) would be measured by a titration with acid or base. • Confirm that an increased neutralization number indicates a significant change in the oil’s chemical condition, especially in terms of potential corrosive action on engine parts.