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I was studying the designation of names to refrigerants.

The following is the basic formula:

R - (m - 1) ( n + 1) ( o )

where:
m = number of carbon atoms in the refrigerant
n = number of hydrogen atoms in the refrigerant
o = number of fluorine atoms in the refrigerant

So R-134a has:

1 + 1 = 2 carbon atoms
3 - 1 = 2 hydrogen atoms
4 fluorine atoms

What does the 'a' at the end mean?

hazzey
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Fennekin
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2 Answers2

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R134a..Here "a" is used to denote that it is an isomer. R134 and R134a have same chemical formula and atomic weight but different chemical structures.

R134 has NBP of about -19 C whereas R134a has a NBP of about -26C.

And dont use capital 'A' in R134a …. "A" denotes that the refrigerant is non -azeotropic.

ResearchGate

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morristtu
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If a refrigerant contains 'a' at its end it is the isomer of that refrigerant. Example 'R123' is 'C2H2F3Cl2' and 'R123a' is the isomer of the same molecule.

Rohit Joshi
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