The heat of fusion of acetone is 5.7 kJ/mol. Calculate to two significant figures the entropy change when 6.3 mol of acetone melts at its melting point of -94.7C at constant pressure

The entropy change of the process is

Explanation:

To calculate the entropy change for different phase at same temperature, we use the equation:

where,  

= Entropy change

n = moles of acetone = 6.3 moles

= enthalpy of fusion = 5.7 kJ/mol = 5700 J/mol    (Conversion factor:  1 kJ = 1000 J)

T = temperature of the system =

Putting values in above equation, we get:

Hence, the entropy change of the process is

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

answer by yourhope:

how do models compare to real-world objects?

d. most models represent a real-world object in a simpler way.

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