Question

You will be using the observations given in the scenarios i - vi below to determine which of the following is true for G (a - c), which of the following is true for S (d - f) and which of the following is true for H (g - i).
Scenarios:

i. A spontaneous reaction is taking place in a flask. When you touch the flask, it feels cold and gets colder as the reaction progresses.
Input format: in alphabetical order something like c,d,i

ii. A spontaneous reaction is taking place in a flask as evidenced by the formation of gas bubbles. When you touch the flask, it feels hot and gets hotter as the reaction progresses.
Input format: in alphabetical order something like c,d,i

iii. A spontaneous reaction is taking place in a flask. When you touch the flask, it feels hot and gets hotter as the reaction progresses.
Input format: in alphabetical order something like c,d,i

iv. A spontaneous reaction is taking place in a flask. You notice the formation of gas bubbles intensifies as the reaction progresses.
Input format: in alphabetical order something like c,d,i

v. A solid in a closed flask begins to melt. (You can consider this a phase change.)
Input format: in alphabetical order something like c,d,i

vi. A liquid begins to appear on the inside of a closed flask. At first glance before the liquid began to appear, you might have thought the flask was empty. (You can consider this a phase change.)


a. The sign of G is positive.
b. The sign of G is negative.
c. Cannot determine the sign of G from the information given.
d. The sign of S is positive.
e. The sign of S is negative.
f. Cannot determine the sign of S from the information given.
g. The sign of H is positive.
h. The sign of H is negative.
i. Cannot determine the

Answer 1

Answer:

A spontaneous reaction is taking place in a flask. When you touch the flask, it feels cold and gets colder as the reaction progresses........(c,f,g)

A spontaneous reaction is taking place in a flask as evidenced by the formation of gas bubbles. When you touch the flask, it feels hot and gets hotter as the reaction progresses.... (c,d,h)

A spontaneous reaction is taking place in a flask. When you touch the flask, it feels hot and gets hotter as the reaction progresses....(c,f,h)

A spontaneous reaction is taking place in a flask. You notice the formation of gas bubbles intensifies as the reaction progresses....(c,d,I)

A solid in a closed flask begins to melt. (You can consider this a phase change.)....(b,d,g)

A liquid begins to appear on the inside of a closed flask. At first glance before the liquid began to appear, you might have thought the flask was empty. (You can consider this a phase change.)....(a,e,h)

Explanation:

Now it is necessary here to state the equation for ∆G

∆G= ∆H-T∆S

The values of ∆G depends on the relative values of ∆H, T and ∆S.

When heat is evolved by a system, ∆H is negative, when heat is absorbed by a system, ∆H is positive.

When gases are evolved, ∆S is positive, when gases turn to liquids or solids ∆S is negative.

Let us also recall that, for the melting process ∆S positive ( solid changes to liquid), ∆H is positive(energy is absorbed) and T increases( the substance is heated). Hence ∆G is negative

For the condensation process; ∆H is negative (heat is evolved), ∆S is negative (gas changes to liquid) and T is decreased hence ∆G is positive.