Answer:
Products are stearate anion and water.
Step-by-step explanation:
Stearic acid is a 18-carbon chain molecule containing -COOH group. IUPAC name of stearic acid is octadecanoic acid. 
Molecular formula of stearic acid is 
.
When 
 is added into stearic acid, 
 removes a proton (
) from acidic -COOH group and forms stearate anion and water as products.
The balanced acid-base reaction is given as: 
 

Structure of products are given below.