Solve Stoichiometry Help: Making a 405g Bar of Soap

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SUMMARY

The discussion focuses on the stoichiometry involved in the saponification process for making a 405g bar of soap using trioleic acid (TOA) and sodium hydroxide (NaOH). The molar mass of TOA is 848g/mol, while the resulting soap has a molar mass of 304g/mol. The correct saponification reaction is Triolein + 3NaOH → 3 Soap + 1 Glycerol, with Triolein having a molar mass of 885.4g/mol. Participants seek clarity on calculating the required amounts of lard and lye without excess, highlighting the importance of understanding molar ratios in chemical reactions.

PREREQUISITES
  • Understanding of saponification and its chemical equations
  • Knowledge of molar mass calculations
  • Familiarity with stoichiometric ratios in chemical reactions
  • Basic chemistry terminology, including triglycerides and carboxylic acids
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  • Research the detailed process of saponification and its applications in soap making
  • Learn how to calculate molar masses and perform stoichiometric conversions
  • Explore the differences between various types of triglycerides used in soap production
  • Study the balanced equations for combustion reactions and their stoichiometric implications
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Chemistry students, hobbyist soap makers, and anyone interested in the chemical processes behind soap production and stoichiometry.

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Homework Statement


Saponification is the process by which soap is made. A triglyceride is reacted with NaOH to produce a carboxylic acid salt (the soap) and glycerol
Lard, mostly made of trioleic acid (TOA) is used with Lye (NaOH) in homemade variations
molar mass of TOA is 848g/mol
molar mass of resulting soap is 304g/mol


Homework Equations


TOA + 3NaOH --> 3 Soaps+ 3 glycerol

Question: if you want to make a 405g bar of soap with no excess lard or lye what amounts of lard and lye are needed.

The Attempt at a Solution



i have no idea how to do this problem. I know you start with 405g soap/1 to 1mol soap/(idk how much soap weighs per mol)
 
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Firstly, you must realize that this question is a bit hypothetical since animal fats are saturated, unlike 'trioleic acid'. That would be tristearic acid in your nomenclature. An alternative nomenclature is to say 'triolein' for the glyceryl ester of oleic acid (olive oil) and 'tristearin' for the glyceryl ester of stearic acid (lard).

You are given the molar mass of the TOA and the resulting soap in the problem but I have no idea how those numbers were arrived at... perhaps thin air? The amount of soap produced from TOA is therefore given by a ratio of these two numbers multiplied by number. Can you take it from there?
 
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BTW, The correct saponification reaction (not your problem, certainly) would be:

Triolein + 3NaOH \rightarrow\ 3 Na^+ ^-OOC-C_{17}H_{33} + 1 glycerol

where the formula weight of triolein is 885.4 g/mol and the formula weight of the soap is 304.4.
 
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a little more help

thanks a lot
heres another wuestion i need help with

the fuel used to power booster rockets is represented in The balanced equation
3Al + 3NH4CIO4 ? Al2O3 + 3NO + 6H2O

if ____e5kg Aluminum reacts with an excess of ammonium perchlorate (say____e6kg) what is the mass of nitrogen vapor produced

im supposed to fill in the blanks with any numbers that i want but i don't know what "e5kg" and "e6kg" mean.
 

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