thermochem

Internal energy

molecular composition

what type of energy does a glass of water contain

internal energy

Heat

molecular temperature

is Kinetic energy (KE) is proportional to an object's velocity.

yes

typical definition of energy?

The capacity to do work

What type of energy is increasing when... turning on a light bulb

internal energy

What type of energy is increasing when... An egg falls from a table

Kinetic energy

What type of energy is increasing when...Water begins to boil

potential energy

What type of energy is increasing when... water begins to freeze

Potential energy

What type of energy is increasing when... a skateboard rolls on flat ground

kinetic energy

Potential Energy (PE)

molecular motion

Potential energy is

molecular position

endothermic means

heat enters from surrounds

exothermic means

releases heat to surroundings

endothermic is what in the equation

enters as reactant

exothermic in equation is

exits as a product

If energy is produced during a chemical reaction, then the reaction is

exothermic

State functions are known to be

path-independentfunctions.

what describes a state function?

A path-independent function

458 kJ is equivalent to how many calories (cal)?

1.09E5

Which quantity of energy is the biggest: 65.4 kJ or 3.21 x 10 kWh?

65.4 kJ

is (1253 Cal > 11553 cal) correct?

true

Which of the following is not a unit of energy?
J, K, kJ, cal

K

Convert 234 kJ to kcal. Only include the numerical value in your answer.

5.59E1

Convert 614 Cal to J. Only include the numerical value in your answer.

2.57E6

Convert 5.78 x 10 kWh to kJ. Only include the numerical value in your answer.

2.08E6

Convert 1.28 x 10cal to kWh. Only include the numerical value in your answer.

1.49E-9

Convert 202 CV to Ws. Only include the numerical value in your answer.

2.02E2

If electricity costs $0.12 per kWh, then what is the total cost for a family of four to illuminate ten 60 watt bulbs each for 30 days? (Round to the nearest dollar)

207.0

You observe a cup containing ice that is melting inside a room at temperature 25 C. Identify the correct statement.
a The change in heat with respect to the ice is negative
bThe ice cube is the system and gains heat from the higher temperature room
cThe change in heat with respect to the room is positive
dThe ice cube melts because cold energy exits and enters the room

B

does A negative heat (-q) implies an exothermic reaction?

yes
A negative sign for q means that the system is losing heat; an exothermic process.

Work is done by a gas whenever

For work to be done, the gas must change volume, ∆V≠0.

the equation representing expansion work.

w= - PΔV

are Heat and thermal energy are the same thing?

no
Heat is the energy that flows from a higher temperature object to a lower temperature object as a result of their temperature difference. Thermal energy is the energy associated with the incessant and haphazard motion of atoms or molecules above absolute zero (0 Kelvin).

A constant volume calorimeter (bomb calorimeter) was calibrated by performing in it a reaction in which 5.23 kJ of heat energy was released, causing the calorimeter to rise by 7.33 °C. What is the heat capacity C of the calorimeter?

7.14E-1

Next, a chemical reaction of interest was conducted in the same constant volume calorimeter. The neutralization reaction of HCl(aq) with NaOH(aq) caused the temperature of the calorimeter to rise by 2.46 °C.What is the change in internal energy ΔU of the neutralization reaction in kJ?

-1.76E0
explanation
△U=qrxn​=−Cv​△T=(−0.714kJ/K)(2.46K)=−1.76kJ

A typical hamburger has a serving size of 105 g and consists of approximately 20% protein (21.0 g), 33% fat (34.7 g), and 47% carbohydrate (49.3 g). Assume that the heat capacity of the bomb calorimeter is 8.39 kJ K-1, and the increase in water temperature was 13.2 K.

How many Calories (Cal) are in the hamburger described above?

2.65E1

If the same hamburger was placed in a different bomb calorimeter whose is 7.66 kJ K, then what would be the change in temperature of the water bath?

1.45E1

is this statement true(A material with a greater specific heat capacity will experience a greater temperature change than a material with a smaller specific heat capacity per unit of heat)?

false

How much heat (in kJ) is needed to heat a 200.0 mL sample of water initially at 25.0 °C to a boiling temperature of 100.0 °C?

6.28E1

A 6.88 g piece of copper is heated from 20.0 C to 125 C and then submerged in 45.0 mL of water initially at 18.3 C. What is the final temperature of the water?

1.98E1

Isobaric calorimetry

is also known as coffee-cup calorimetry.

Isochoric calorimetry

is also known as bomb calorimetry.

Isobaric condition

takes place under constant pressure

Isochoric condition

takes place under constant volume

Isobaric measurement

the amount of heat transferred is equal to ΔH

Isochoric measurement

all energy is transferred in the form of heat

When hydrogen gas reacts with oxygen gas under certain conditions to produce liquid water, 572.0 kJ of heat energy is released. Is the reaction exothermic or endothermic?

exothermic
We are told that energy is released in the form of heat. By definition, this is an exothermic process.

When hydrogen gas reacts with oxygen gas under certain conditions to produce liquid water, 572.0 kJ of heat energy is released. What is the enthalpy change of the reaction when exactly 67.50 grams of water vapor forms?

-1071 kJ

What is the enthalpy of formation (, in kJmol) of Pb(NO)(s) ?

-4.519E2

Write an equation for the enthalpy of formation of NaHCO(s).

Na(s), H(g), O(g), C(s, graphite)

The standard enthalpy of formation () of any element in its standard state is always zero. True or false?

true,The standard state of an element is its states as a solid, liquid or gas to atmosphere of pressure and 25 °C.

Consider the reaction of nitrogen dioxide with molecular hydrogen:2 NO(g) + 7 H(g) → 4 HO(l) + 2 NH(g)
Calculate for this reaction given by manipulation of reactions (i) and (ii):
2 NH(g) → N(g) + 3 H(g) = +92.0 kJ (i)
N(g) + 4 HO(l) → 2 NO(g) + 4 H(g) = +3.40E2 kJ (ii)

-4.32E2
Our first task is to find a puzzle - piece containing 2 NO2(g) as a reactant. We see that equation (ii) has 2 NO2 (g) as a product. we know to reverse this reaction to make the product 2 NO2 (g) a reactant instead:
With our first puzzle-piece in place the next piece is 7 H2(g) as a reactant. There are already 4 H2 (g) molecules in the above reaction so we need only 3 more H2(g) to make 7 H2(g) the extra 3 H2(g) come from the reverse of (i):
Summing the reactant and product and allow us to cancel N2(g) as a spectator

Joule

a derived SI unit of energy equivalent to 1 kg m2 s-2.

Isolated system

- a system that cannot transfer energy or matter.

Closed system

a system that can transfer energy but not matter.

Open system

a system that can transfer energy and matter.

Internal energy

molecular composition

what type of energy does a glass of water contain

internal energy

Heat

molecular temperature

is Kinetic energy (KE) is proportional to an object's velocity.

yes

typical definition of energy?

The capacity to do work

What type of energy is increasing when... turning on a light bulb

internal energy

What type of energy is increasing when... An egg falls from a table

Kinetic energy

What type of energy is increasing when...Water begins to boil

potential energy

What type of energy is increasing when... water begins to freeze

Potential energy

What type of energy is increasing when... a skateboard rolls on flat ground

kinetic energy

Potential Energy (PE)

molecular motion

Potential energy is

molecular position

endothermic means

heat enters from surrounds

exothermic means

releases heat to surroundings

endothermic is what in the equation

enters as reactant

exothermic in equation is

exits as a product

If energy is produced during a chemical reaction, then the reaction is

exothermic

State functions are known to be

path-independentfunctions.

what describes a state function?

A path-independent function

458 kJ is equivalent to how many calories (cal)?

1.09E5

Which quantity of energy is the biggest: 65.4 kJ or 3.21 x 10 kWh?

65.4 kJ

is (1253 Cal > 11553 cal) correct?

true

Which of the following is not a unit of energy?
J, K, kJ, cal

K

Convert 234 kJ to kcal. Only include the numerical value in your answer.

5.59E1

Convert 614 Cal to J. Only include the numerical value in your answer.

2.57E6

Convert 5.78 x 10 kWh to kJ. Only include the numerical value in your answer.

2.08E6

Convert 1.28 x 10cal to kWh. Only include the numerical value in your answer.

1.49E-9

Convert 202 CV to Ws. Only include the numerical value in your answer.

2.02E2

If electricity costs $0.12 per kWh, then what is the total cost for a family of four to illuminate ten 60 watt bulbs each for 30 days? (Round to the nearest dollar)

207.0

You observe a cup containing ice that is melting inside a room at temperature 25 C. Identify the correct statement.
a The change in heat with respect to the ice is negative
bThe ice cube is the system and gains heat from the higher temperature room
cThe change in heat with respect to the room is positive
dThe ice cube melts because cold energy exits and enters the room

B

does A negative heat (-q) implies an exothermic reaction?

yes
A negative sign for q means that the system is losing heat; an exothermic process.

Work is done by a gas whenever

For work to be done, the gas must change volume, ∆V≠0.

the equation representing expansion work.

w= - PΔV

are Heat and thermal energy are the same thing?

no
Heat is the energy that flows from a higher temperature object to a lower temperature object as a result of their temperature difference. Thermal energy is the energy associated with the incessant and haphazard motion of atoms or molecules above absolute zero (0 Kelvin).

A constant volume calorimeter (bomb calorimeter) was calibrated by performing in it a reaction in which 5.23 kJ of heat energy was released, causing the calorimeter to rise by 7.33 °C. What is the heat capacity C of the calorimeter?

7.14E-1

Next, a chemical reaction of interest was conducted in the same constant volume calorimeter. The neutralization reaction of HCl(aq) with NaOH(aq) caused the temperature of the calorimeter to rise by 2.46 °C.What is the change in internal energy ΔU of the neutralization reaction in kJ?

-1.76E0
explanation
△U=qrxn​=−Cv​△T=(−0.714kJ/K)(2.46K)=−1.76kJ

A typical hamburger has a serving size of 105 g and consists of approximately 20% protein (21.0 g), 33% fat (34.7 g), and 47% carbohydrate (49.3 g). Assume that the heat capacity of the bomb calorimeter is 8.39 kJ K-1, and the increase in water temperature was 13.2 K.

How many Calories (Cal) are in the hamburger described above?

2.65E1

If the same hamburger was placed in a different bomb calorimeter whose is 7.66 kJ K, then what would be the change in temperature of the water bath?

1.45E1

is this statement true(A material with a greater specific heat capacity will experience a greater temperature change than a material with a smaller specific heat capacity per unit of heat)?

false

How much heat (in kJ) is needed to heat a 200.0 mL sample of water initially at 25.0 °C to a boiling temperature of 100.0 °C?

6.28E1

A 6.88 g piece of copper is heated from 20.0 C to 125 C and then submerged in 45.0 mL of water initially at 18.3 C. What is the final temperature of the water?

1.98E1

Isobaric calorimetry

is also known as coffee-cup calorimetry.

Isochoric calorimetry

is also known as bomb calorimetry.