[Ciubba]

Liquid sodium is being considered as an engine coolant. How many grams of liquid sodium are needed to absorb 1 MJ of energy in the form of heat if the temperature of the sodium is not to increase by more than 10 degrees Celsius. Take Cp=30.8J /(mol K) for Na(l) at 500k

30.8 J/(mol k) * (1mol/23 g)=1.339 J/(g K)
Cp=H/(T x), where x is number of grams needed.

Solving this equation, I get 7.46*10^4 g; however, the book lists the answer as being 7.46*10^-4. Where did I go wrong?

[Borek]

Without checking any math, their order of magnitude is blatantly wrong. You can't absorb MJ in mg without creating a hot plasma.

[curiouscat]

I get 74 kg.