Thermochemistry

Question 1

What is energy?

Answer 1

Capacity to do work

Question 2

What is work?

Answer 2

Result of force acting through a distance

Question 3

What is heat?

Answer 3

Flow of energy caused by tempersture difference

Question 4

What is the system vs the surroundings?

Answer 4

What we chose to study

Everything the system can exchange energy with

Question 5

How to convert joules to calories?

Answer 5

Multiply by 4.184

Question 6

What is the internal energy (U) of a system?

Answer 6

Sum of kinetic and potential energies of all particles that compose the sustem

Question 7

What is the equation for the change in internal energy?

Answer 7

delta U= q+w

Question 8

What are the sign conventions for heat?

Answer 8

Positive system GAINS energy

Negative system LOSES energy

Question 9

What are sign conventions for work?

Answer 9

Positive work done ON the system

Negative work done BY the system

Question 10

What are sign conventions for delta U?

Answer 10

+ energy flows INTO the system
- energy flows OUT of system

Question 11

Since nervy must be conserved -delta U of the system equals?

Answer 11

Delta U of surroundings

Question 12

What is the equation for heat?

Answer 12

q=mcdeltaT

Question 13

What is equation for molar heat capacity?

Answer 13

q=ncdeltaT

Question 14

How can you solve a problem where equilibrium is reached between aluminum and water?

Answer 14

-qAl=qH2O

Question 15

How can you calculate work?

Answer 15

w=-PdeltaV

Question 16

How many liters are in a m^3

Answer 16

1000

Question 17

What is the formula for work that uses the change in coefficients?

Answer 17

w=-detanRT

Question 18

If the volume is constant what does the heat equal?

Answer 18

The change in internal energy

Question 19

How can we relate the temperature change to the heat ablatives by a calorimeter?

Answer 19

qcal=CcaldeltaT

Question 20

If no heat escapes the calorimeter the heat gained by the calorimeter equals?

Answer 20

The heat released by reaction

qcal=-qr

Question 21

What is enthalpy?

Answer 21

Heat involved in reaction at constant pressure

Question 22

What is the formula for the change in enthalpy?

Answer 22

deltaH=deltaU+PdeltaV

Question 23

What does heat at constant pressure equal?

Answer 23

Change in enthalpy

Question 24

The formula for enthalpy of reaction is?

Answer 24

DeltarH=DeltarU+deltanRT

Question 25

What does delta n stand for?

Answer 25

change in coefficients of gases in balanced chemical equations

Question 26

What does heat divided by moles equal?

Answer 26

DeltarH

Question 27

In coffee cup calorimeters the heat gained by the solution is equal to?

Answer 27

Heat lost by reaction

qsol’n=-qr

Question 28

In coffee cup calorimeters qr equals?

Answer 28

qr=qp=deltaH

Question 29

What does bomb calorimeters measure?

Answer 29

Change in internal energy

Question 30

What is coffee cup calorimeter used to determine?

Answer 30

deltarH

Question 31

What is the formula for q solution?

Answer 31

Qsoln=msoln csoln deltaT

Question 32

How can you find moles?

Answer 32

Dividing mass by molar mass or ideal gas law

Question 33

How many joules are in one L bar?

Answer 33

100