Using the first law of thermodynamics explain why the specific latent heat of vaporisation of water is greater than the specific latent heat of fusion of ice.

The first law of thermodynamics (conservation of energy) has nothing to do with why vaporization requires more energy than melting. I have no idea what you instructor had in mind when assigning this question, and would be interested in hearing his or her version of the answer.

You have to consider the intramolecular binding process itself. Vaporizing requires that the molecules separate from each other by "climbing out" of a potential-energy "well" created by van der Waals intramolecular dipole-dipole binding forces. This requires a certain amount of enery that is typically on the order of an electron volt per molecule.

When a substance melts, the intramolecular distance does not change much, and the vearious molecules still remain bound to each other, but the orientation of the molecules changes with the added thermal energy so that they are not held as tightly and are not locked into a particular crystalline orientation.

Basically, it takes more energy to break away from adjacent molecules than to wiggle to a different, less ordered, stacking pattern.

which one of the following temperatures is equal to 5*c?

A. 0K
B. 41K
c. 278K
d. 465 K

C: 5 + 273 = 278 K

To convert degrees Celsius to Kelvin, you need to add 273.15 to the Celsius temperature. Let's do that for each answer choice:

A. 0K + 273.15 = 273.15K
B. 41K + 273.15 = 314.15K
C. 278K + 273.15 = 551.15K
D. 465K + 273.15 = 738.15K

Among the given answer choices, option A, 273.15K, is equal to 5°C.

To find the temperature that is equal to 5°C, we need to convert the Celsius temperature to Kelvin. The Kelvin scale is an absolute temperature scale where 0K represents absolute zero.

To convert Celsius to Kelvin, we need to add 273.15 to the Celsius temperature.

So,

5°C + 273.15 = 278.15K

Therefore, the temperature that is equal to 5°C is 278K. The correct answer is option C.