Question

A). Suppose you had a gypsum crystal with a mass of 25.320 g & volume was 10.96 ml. Put both of these numbers into scientific notation and indicate how many significant figures are in each number.

) Alcohol baths used to be used to decrease the body temperature of a person with a fever. This was done by rubbing the person down with alcohol.

(2pts) Explain this use of alcohol given the following thermochemical equation;

                                    C₂H₅OH(l) à C₂H₅OH(g)                       DH^o = 42.2 kJ/mol

(2pts) If a person is rubbed down with 250mL of alcohol and it all evaporates, how much heat exchange is occurring? (Density of alcohol is 0.786 g/mL at 20^oC.)

(2pts) Viewing the alcohol liquid as the system, what was the initial volume of gaseous alcohol?

(2pts) If the final volume of gaseous alcohol after evaporation was 4.85 L Calculate the work done(in your town using the pressure on the day you used completed this exam- cite source) as the alcohol vapor expanded into the environment

(2pts) From this information, calculate the change in internal energy(E) for the “system” we defined above. Is it positive or negative? What does this mean? What is the system in this example?

(2pts) What would happen to the energy of the surroundings? What is the surroundings in this case?

Answer 1