How do you approximate between the Cp of a gas and a solid?

[Will26040]

TL;DR

I have the Cp of Benzoyl peroxide (BPO) in gas form (454.39 J/molK). What approximation could I make to find the Cp of solid BPO?

I have the Cp of Benzoyl peroxide (BPO) in gas form (454.39 J/molK). What approximation could I make to find the Cp of solid BPO as I cannot find this info online? thanks

 

[Chestermiller]

Have you heard of the Dulong and Petit law?
Also, https://pubs.acs.org/doi/10.1021/i160013a003

 

[Will26040]

Have you heard of the Dulong and Petit law?
Also, https://pubs.acs.org/doi/10.1021/i160013a003

Thanks! do you have any idea on how I would check the accuracy of my obtained value? I am not sure where to find a literature value