First Law for Isobaric Process (ΔQ = ΔU + PΔV)

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ΔQ = ΔU + PΔV

What each symbol means

SymbolWhat it stands for
PConstant pressure (Pa)
ΔQHeat supplied to system (J)
ΔUChange in internal energy (J)
ΔVChange in volume (m³)

When to use this

For gas in cylinder with movable piston at constant pressure. Combines First Law with work expression for isobaric process.