Robert C. answered • 10/11/12

Dr. Robert can help you with Math and Science

You are on the right track. Solve for m using the equation you wrote. Since your Cp is in J/K mol, your m term is in moles. Use the atomic mass of sodium to convert these moles to grams (1 mol sodium = 23 g sodium).

Mass (grams) = 23 g/mol x (4 x 10^6 J)/[(30.8 J/K mol) (10 K)]