Is the system’s entropy change positive or negative?

• Water vapor deposits as ice crystals on a cold windowpane

• A can of carbonated beverage loses its fizz (Consider the beverage but not the can as the system.)

• A glassblower heats glass to its softening temperature

• Water boils

• A teaspoon of sugar dissolves in a cup of coffee. (The system consists of both sugar and coffee.)

• Calcium carbonate precipitates out of water in a cave to form stalactites and stalagmites. (Consider only the calcium carbonate to be the system.)

Which one has a higher entropy?1 or 2

Be able to explain why

• Solid carbon dioxide at -78C

• Carbon dioxide vapor at 0C

• Solid sugar • Sugar dissolved in tea

• 100mL of water and 100mL of alcohol

• 100mL of water and 100mL of alcohol mixed together

• Cl2 (g) • P4 (g)

• NH4NO3(s) • NH4NO3(aq)

• AsH3(g) • Kr(g)

• CH3OH(l) • C2H5OH(l)

Predict whether the entropy change would be positive or negative

Be able to explain why

• C2H4(g) + H2(g) C2H6(g)

• CH3OH(l) CO(g) + 2H2(g)

• Ag+(aq) + I-(aq) AgI(s)

• Br2(l) + H2(g) 2HBr(g)

• CaCO3(s) CaO(s) + CO2(g)