The liter atmosphere, or LATM, is a unit of measurement applied to work and energy, particularly within the study of confined gases. The joule, named after James P. Joule, is the work or energy unit in the International System of Units, or SI. Both units are used in chemistry to measure the energy in a system, and it is sometimes necessary to convert between them. The math involved is simple, but due to the value of the conversion factor, a calculator is required.
Things You'll Need
 Calculator

Determine your LATM value. For example, suppose you want to convert 3.5 LATM to joules.

Multiply the LATM value by 101.325, the number of joules equivalent to 1 liter atmosphere. In the example, you would multiply 3.5 LATM by 101.325 to obtain 354.638. The result is the value expressed in joules.

Append the suffix "J" to the result to show that it is a value measured in joules. A capital "J" is the SI symbol for joules.
Tips & Warnings
 Check for errors by dividing the result by 101.325. If the result is not the original value in LATM, there was an error in the calculations.
References
 University of North Carolina at Chapel Hill; How Many? A Dictionary of Units of Measurement  L
 University of North Carolina at Chapel Hill; How Many? A Dictionary of Units of Measurement  J
 BBC: Tutor’s Toolkit: Application of Number
 University of Arizona Department of Chemistry: Matter  States of Matter
 Temple University Chemistry Department: Selected Physical Constants Useful in Chemistry
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