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1 year ago in Chemistry , Physical Chemistry By Adithi

How does the density of ethanol change with temperature?

In my lab, we use ethanol as a solvent for temperature-sensitive reactions and for calibrating instruments. A small error in volume-to-mass conversion due to temperature change can affect yield calculations and calibration accuracy. I'm looking for the functional trend and a rule-of-thumb for its magnitude in everyday lab conditions.

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By Varun Answered 1 year ago

From my experience in analytical chemistry labs, this is a critical detail for precision. Ethanol's density decreases almost linearly with increasing temperature, like most liquids. Around room temperature, the coefficient is roughly -0.001 g/mL per °C. This means a 5°C change introduces a ~0.5% error in mass if you're measuring by volume. For practical work, I always recommend using a temperature-corrected density table or a calibrated volumetric flask at a specified temperature. Never assume the density on the bottle is correct if your lab temperature fluctuates.

 

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