in 1936 Jesse Owens, and American track star, beat a race horse over a 100 yard course. It took him only 5.5 seconds. What is his speed in miles per hour?

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.  

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.