Thermodynamics, thermochemistry, and related

Question 1

If deltaG has a positive sign, what does that say about the spontaneity of the reaction?

Answer 1

That the reaction is spontaneous, but only in the reverse direction.

Question 2

If deltaG has a negative sign, what does that say about the spontaneity of the reaction?

Answer 2

That the reaction is spontaneous in the forward direction.

Question 3

If deltaG is 0, what does that say about the reaction?

Answer 3

That the reaction is nonspontaneous.

Question 4

What are the natural tendencies for a spontaneous reaction?

Answer 4

Exothermic and an increase in entropy

Question 5

If a reaction has a negative sign for both Enthalpy and Entropy, then at what temperatures will the reaction favor? (High or low temps)

Answer 5

Low temps.

Question 6

When looking at a graph of spontaneity, at what sign will the reaction be spontaneous?

Answer 6

In the negative quadrants.

Question 7

When looking at a graph of spontaneity, what variable controls the slope? And at what sign is this variable going to make the slope of the line positive?

Answer 7

• deltaS (entropy)

- If entropy is negative then the slope will be positive.

Question 8

What is the lowest temperature that can be attained in units of Kelvin?

Answer 8

0^K

Question 9

How do you calculate weight percent? (concentration)

Answer 9

grams solute/total grams of solution multiplied by 100%

Question 10

How do you calculate moLALity? (concentration)

Answer 10

mol solute/kilograms of solvent

Question 11

How do you calculate mole fraction? (concentration)

Answer 11

mol solute/total moles in solution

Question 12

What is true for all calculations of concentration(M, molal, wt%, mole fraction, normality)

Answer 12

They all have a certain unit of solute on top, and a certain unit of solution on bottom. EXCEPT molality.

Question 13

What is the equation for Normality? (concentration)

Answer 13

equivalents of solute/liters of solution

Question 14

What is the equation for finding the parts per million(ppm)? (concentration)

Answer 14

grams solute/grams solution multiplied by 10^6

Question 15

How many grams are in 1 mL?

Answer 15

1 gram

Question 16

How many joules are in one calorie?

Answer 16

4.184 J

Question 17

How many Joules are in one British Thermal Unit?

Answer 17

1055 J

Question 18

Is bond breaking exothermic or endothermic?

Answer 18

Endothermic

Question 19

Is bond forming exothermic or endothermic?

Answer 19

Exothermic

Question 20

If the system does work on the surroundings then what is the sign for work?

Answer 20

Negative

Question 21

If the surroundings do work on the system then what is the sign for work?

Answer 21

Positive

Question 22

In a spontaneous reaction, what is the tendency for enthalpy?

Answer 22

For it to be exothermic

Question 23

If volume increases, what happens to the entropy of the system?

Answer 23

It increases. More space=more rooms for bouncing around

Question 24

What does a negative sign on deltaG indicate?

Answer 24

That the reaction is spontaneous

Question 25

What does a positive sign on deltaG indicate?

Answer 25

That a reaction is non-spontaneous

Question 26

In a Gibbs equation, if the sign on deltaH and deltaS is both negative, then what will that yield for the spontaneity of the reaction?

Answer 26

A tendency to be spontaneous at low temperatures.

Question 27

In a Gibbs equation, if deltaH and deltaS are both positive, then what does that indicate for the spontaneity of the reaction?

Answer 27

That the reaction will | Be spontaneous at high temperatures.

Question 28

What is the definition of a homogeneous mixture?

Answer 28

That a solution has the solute and solvent mixed evenly throughout it. "Top drink, bottom drink"

Question 29

What is a colligative property?

Answer 29

A property of a solution that changes depending on how much solute is dissolved within the solution.