# What is the substance with the highest specific heat?

I always learned that water has the highest specific heat, but I recently saw that Hydrogen has a specific heat as high as 14 cal/gC and helium has a specific heat of 5 cal/gC, which would be much higher than water? Is this true? and how can it be if there are so many "proofs" in nature , showing that water has the highest specific heat?

• – A.K. Oct 30 '18 at 1:13
• Thanks - I looked there but it does not answer my question. – suse Oct 30 '18 at 1:21
• Yes, that's true, except that the figures are in Joules, not calories. Still, they are a good deal bigger than that for water. There is nothing strange or anomalous about it. – Ivan Neretin Oct 30 '18 at 6:01
• You would be better to compare heat capacity in joules/mole/K rather than mass, in that case hydrogen is approx 28 , water approx 75, but for example benzene 117 and anthracene 211. – porphyrin Oct 30 '18 at 10:00

This may not be the absolute highest, but on a mass basis hydrogen gas has more than three times the specific heat as water under normal laboratory conditions. Diatomic gases under ambient conditions generally have a molar specific heat of about $$7\text {cal/(mol K)}$$, and one mole of hydrogen has only $$2\text {g}$$ mass. Thus $$3.5\text {cal/(g K)}$$ for hydrogen versus $$1\text {cal/(g K)}$$ for water.
Helium, contrary to the question, is $$5\text {cal/(mol K)}$$, not $$7\text {cal/(g K)}$$.