What is the specific heat capacity of ice at −200 degrees Celsius?

All the data I found online just goes as low as $$-100\ ^\circ \text{C}$$. If the specific heat value of ice at this temperature is unknown, as in has never been tested, would plugging the known values into a table and predicting the value with an algorithm work? So far the values I have seen seem to line up pretty well to form a linear graph.

• You are right, it is a linear graph. The table only makes it easier, you don't need the tables, just plug in the number in the formula and you will get the value that you need. You can totally extrapolate as long as the the state the state is same. Commented Jul 15, 2019 at 17:36
• Great, thank you! Commented Jul 15, 2019 at 18:03
• As temp goes to absolute 0, heat capacity goes to zero. And its graph is proportional to T to the third power. Commented Nov 27, 2022 at 0:00

According to “Properties of Ice and Supercooled Water”, in CRC Handbook of Chemistry and Physics, 90th Edition (CD-ROM Version 2010), David R. Lide, ed., CRC Press/Taylor and Francis, Boca Raton, FL., the specific heat capacity of ice at $$T=-200\ \mathrm{^\circ C}$$ is $$c_p=0.67\ \mathrm{J\ g^{-1}\ ^\circ C^{-1}}$$.
According to “Properties of Ice and Supercooled Water”, in CRC Handbook of Chemistry and Physics, 97th Edition (2016), William M. Haynes, ed., CRC Press/Taylor and Francis, Boca Raton, FL., it is $$c_p=0.65\ \mathrm{J\ g^{-1}\ ^\circ C^{-1}}$$.