Question

5.1 Thermodynamics 189 5.8 Would the sign of AS be + or - for the following changes? a. liquid gasoline burning to form carbon dioxide and steam b. cleaning up your bedroom c. a stick of dynamite exploding Classify the following as spontaneous or nonsponta- neous processes: a. a hor bowl of oatmeal cooling on the table b. a chemical reaction that gives off free energy 5.10 Classify the following as spontaneous or nonsponta- neous processes: a walking on a treadmill at the gym b. a chemical reaction that requires free energy 5.11 Calculate the number of Calories present in a choco- late chip cookie that contains 17 g carbohydrate, 1 g protein, and 7 g fat. 5.12 Use Table 5.2 to determine how many Calories would be found in a breakfast consisting of two eggs, two pieces of toast buttered with 1 Tbsp of butter, and one 6 fl. oz. glass of orange juice. 5.9 DISCOVERING THE CONCEPTS INQUIRY ACTIVITY-Reaction Energy Diagrams Information The diagrams shown are called reaction energy diagrams and graphically show the progress of two different chemical reactions on the x-axis and the amount of energy required as the reaction moves forward on the y-axis. The activation energy is the amount of energy required to get the reactants into position for collision with enough energy so that they react. Reactions with larger activation energies occur more slowly than reactions with smaller activation energies. Activation energy Products Energy Activation energy Reactants

Answer 1

5.8

a) $\Delta$S is positive this reaction because we know that entropy of a reaction increases if there is an increase in randomness or disorder. For this reaction the disorder is increasing due to the increasing number of gas molecules on combustion.

b) $\Delta$S is negative because cleaning up your bedroom decreases the degree of disorder.

c)  $\Delta$S is positive because of the increase in disorder upon explosion.

5.9

The spontaneous process is one which is capable of proceeding in a given direction without needing to be driven by an outside source of energy whereas non spontaneous process are those process which involve absorption of energy.

a) The process is spontaneous since there is no involvement of external energy.

b) A chemical reaction that requires free energy is a non spontaneous process since the reaction is absorbing energy.

5.10

a) The reaction is spontaneous because the reaction will proceed in a direction to attain equilibrium by releasing the heat from oatmeal without any energy requirements.

b) A chemical reaction that gives of free energy is spontaneous process.

5.11

In order to calculate the number of calories present in given chocolate chip we are taking the sum of number of calories present in given grams of carbohydrates, protein and fat which are given in the question.

Here we are given a chocolate chip which contain 17g carbohydrats, la protein and 7 g fat We know that Ifrom of carbohydrate contain G Am calories: Listilary dig protein contain a calorie If at contain 9 calorie. present in the so the number of calorier I chocolate chips are: Given in question, carbohydral -> 179 protein -) 19 hat ->70 bries persent in chocolate chipsy = 1784 + 1XG + 789 68 + 4 + 63 131, 135 calories are present in the chocolate chips