The molar volume of a certain solid is 140.8 cm3 mol-1 at 1.00 atm and 427.45 K its melting temperature. The molar volume of the liquid at this temperature and pressure is 156.2 cm3 mol-1 at the same temperature and pressure. At 3.3 MPa the melting temperature changes to 429.81 K. Find the enthalpy of fusion of the solid in kJ mol-1.

calculate how many grams of ammonia can be produced from 4.21 grams of

n2 + 3h2 = 2nh3

my answer:

25.0g n2 x (1 mol/ 28.0gn2) x (2 mol nh3/ 1 mol n2) x (17.0g nh3/ 1 molnh3) = 30.36g n2

25.0g h2 x (1 mol h2/ 2.00g h2) x (2 mol nh3/ 3 mol h2) x (17.0g nh3/ 1 mol nh3) = 141.67g h2

lr = n2

not clear

c is the answer because when something is left after something evaporates that shows the chemical change.