Use the information provided below to calculate the quantity of heat (in kJ) required to convert 70.43 g of substance A from an initial temperature of 139.6°C to a final temperature of 70.58°C. The molar mass of the substance is 32.96 g/mol. Melting Point of A = 7.19°C Heat of fusion = 8.74 kJ/mol %3D %3D Boiling point of A = 111°C Heat of vaporization = 67.19 kJ/mol %3D %3D Solid Liquid Gas Specific heat (J/g°C) 2.24 4.45 6.81 Report your answer to the tenths place and do not include units. Do not include a sign with your answer.

Calculate the quantity of heating required to convert the water in four ice cubes (60.1 g each) from H2O(s) at 0 °C to H2O(g) at 100. °C. The enthalpy of fusion of ice is 333 J/g and the enthalpy of vaporization of liquid water is 2260 J/g.

Explain why the enthalpies of vaporization of the following substances increase in the order CH4NH3H2O, even though all three substances have approximately the same molar mass.

Why are steam burns so much worse than water burns even if the H2O is at the same temperature for both phases? Hint: Consider the heat of vaporization of water.

The enthalpy of vaporization of water is larger than its enthalpy of fusion. Explain why.

What is U when 1.00 mol of liquid water vaporizes at 100C? The heat of vaporization, Hvap, of water at 100C is 40.66 kJ/mol.

Consider the phase diagram and heating-curve graphs for Question 113. Draw corresponding heating curves for T1 to T2 at pressures P1 and P2. Label each phase and phase change on your heating curves.

Are changes in state physical or chemical changes? Explain. What type of forces must be overcome to melt or vaporize a substance (are these forces intramolecular or intermolecular)? Define the molar heat of fusion and molar heat of vaporization. Why is the molar heat of vaporization of water so much larger than its molar heat of fusion? Why does the boiling point of a liquid vary with altitude?

Which would you expect to have the higher fusion enthalpy, N2 or I2? Explain your choice.

When I mole of benzene is vaporized at a constant pressure of 1.00 atm and at its boiling point of 353.0 K, 30.79 kJ of energy (heat) is absorbed and the volume change is +28.90 L. What are E and H for this process?