Water is placed in a piston-cylinder device at 20°c, 0.1 mpa. weights are placed on the piston to maintain a constant force on the water as it is heated to 400 °c. how much work does the water do on the piston, per unit mass? sketch the p-v diagram. (this question requires access to thermodynamic tables). (w = 310.2 kj /kg]

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.