Science Buddies: "Ask an Expert"

(Sorry, didn't read the guidelines as well as I thought! Updating this post with proper grammar.)

Hey! This is probably not that great of a question, but I'm unsure where else to ask - I'd ask my teacher, but we're in the midst of winter break right now. In this ScienceBuddies project, the q=mCpΔt equation has Cp as specific heat capacity, which the project states is .001 when converting to kCal. However, in class and around the internet, it seems like the specific heat capacity of water is ~4.18. Is it different for this equation or scenario? I imagine it's not an error with the project itself. Thanks so much!

Moderator Note: I've removed your duplicate post so the experts here will see that your question has not received a reply. Thanks and good luck with your project.

Moderator: Project: https://www.sciencebuddies.org/science- ... alorimeter

Hi - this is a great example of when you need to be careful with units! The number you are seeing, 4.18, is the specific heat capacity of water in joules per (gram * degree Celsius). The value given in the project is in calories per (gram * degree Celsius), 1 cal/(g*deg C) or 0.001 kCal/(g*deg C). One kCal is equal to 4,184 joules, so 0.001 kCal(g*deg C) * 4,184 J/kCal = 4.18 J/(g*deg C). Hope that helps!