All categories

3 years ago

Consider the following enthalpy diagram and enthalpies of intermediate and overall chemical reactions.

Chemistry

2 answers:

SashulF [63]3 years ago

6 0

Answer: The overall chemical reaction is exothermic is the correct statement.

Explanation: As seen from the given image, the reactants are at higher energy level and products are at lower energy level and the excess energy is released in the form of heat. These reactions are considered as exothermic reactions.

Hence, the reaction given in the image is an exothermic reaction.

melomori [17]3 years ago

4 0

The given statement “the overall chemical reaction is exothermic” is true regarding the enthalpy diagram and enthalpies of intermediate and overall chemical reactions.

Further explanation:

Properties are categorized into two types:

1. Intensive properties:

These properties depend on the nature of the substance and not on the size of the system. If the system is further divided into a number of subsystems, the values of intensive properties remain unchanged. Temperature, refractive index, molarity, concentration, pressure, and density are some of the examples of intensive properties.

2. Extensive properties:

These properties depend on the amount of the substance. These are additive in nature if a single system is divided into several subsystems. Mass, enthalpy, volume, energy, size, weight, and length are some of the examples of extensive properties.

Enthalpy:

It is a thermodynamic property that is defined as the sum of internal energy and the product of pressure (P) and volume (V) of the system. It is a state function, an extensive property, and is independent of the path followed by the system while moving from initial to the final point. The total enthalpy of the system cannot be measured directly so its change $\left( {\Delta {\text{H}}} \right)$ is usually measured.

The heat of reaction $\left( {{\Delta }}{{\text{H}}_{{\text{reaction}}}}} \right)$ can have two values:

Case I: If the reaction is endothermic, more energy needs to be supplied to the system than that released by it. So ${\Delta }}{{\text{H}}_{{\text{reaction}}}}$ comes out to be positive.

Case II: If the reaction is exothermic, more energy is released by the system than that supplied to it. So ${\Delta }}{{\text{H}}_{{\text{reaction}}}}$ comes out to be negative.

In the given enthalpy diagram (refer to the attached image), line 1 shows the final or the product state. Line 2 indicates the initial or the reactant state. Line 3 or the dotted line indicates the formation of the first intermediate during the progress of the chemical reaction. Line 4 represents the formation of the second intermediate whose energy is higher than that of first intermediate.

According to the enthalpy diagram, the stable products are formed from the highly energetic unstable intermediate and energy is released during the process. Therefore the overall chemical reaction is exothermic.

In this system, the reactants (line 2) are converted to the first intermediate, represented by line 3. This intermediate is then converted into another higher energy intermediate shown by line 4. The second intermediate is then converted into products, shown by line 1. Therefore three intermediate reactions occur in this system.

The enthalpy of the third intermediate reaction is represented as . This reaction shows the conversion of highly energetic unstable intermediate into products. Since unstable intermediate is to be converted into stable products, this change is accompanied by the release of energy. Therefore the third intermediate reaction is exothermic, not endothermic in nature.

The longest arrow represents only the conversion of higher energy intermediate into products, not the overall reaction. Therefore the longest arrow does not represent the overall chemical reaction.

Learn more:

1. Calculate the enthalpy change using Hess’s Law: brainly.com/question/11293201

2. Find the enthalpy of decomposition of 1 mole of MgO: brainly.com/question/2416245

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Thermodynamics

Keywords: enthalpy, exothermic, endothermic, negative, positive, longest arrow, overall reaction, third intermediate reaction, unstable, stable.

You might be interested in

List the number of each type of atom on the right side of the equation hbr(aq)+2naoh(aq)→2nabr(s)+h2o(l)

ser-zykov [4K]

On the basis of the given unbalanced equation, that is:

HBr (aq) + 2NaOH (aq) → 2NaBr (s) + H2O (l)

On the right side of the equation, there are 2 atoms of sodium (Na), 2 atoms of bromine (Br), 2 atoms of hydrogen (H), and 1 atom of oxygen (O₂).

After balancing the equation correctly we get:

HBr (aq) + NaOH (aq) → NaBr (s) + H2O (l)

On the right side, one atom of Na, 1 atom of Br, 1 atom of H and one atom of O₂.

5 0

3 years ago

Read 2 more answers

Explain how the atom is electrically neutral, having an equal number of protons and electrons.

lord [1]

Answer:

A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other and atom become neutral.

Explanation:

An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.

All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other and atom become neutral. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.

For example

The carbon have six protons and six neutrons so its atomic mass is 12 amu and atomic number is six.

5 0

3 years ago

Help please? I can't figure out earth science

Radda [10]

Answer:

Predict the glaciers' locations.

Explanation:

You must research each glacier, and where it is now. Then try to figure out where it will go. Glaciers can go either forward or backwards, but they move in patterns. Predict!

6 0

3 years ago

Read 2 more answers

Please Help!!

vekshin1

Answer:

1. By Pressure factor: if we double the pressure volume become half of its original

2. 2.14 L

3. 2.15 L

Explanation:

part 1

Data Given:

volume of container change

temperature of remain constant

The pressure doubles

Solution:

This problem can be explained by Boyle's Law that at constant temperature pressure and volume has an inverse relation with each other.

So the volume change due to change in Pressure.

P1V1 = P2V2

if we consider conditions at STP, as follows

initial volume V1 = 22.42 L

and

initial pressure P1 = 1 atm

if the pressure doubles then

final pressure P2 = 2 atm

Put values in Boyle's law equation

(1 atm) (22.42L) = (2 atm) (V2)

Rearrange the above equation to find V2

V2 = (1 atm) (22.42L) / 2 atm

V2 = 11.12 L

So it is clear from calculation if we double the pressure volume become half of its original. So its the pressure due to volume become effected and decrease by its increase.

_____________

Part 2

Data Given:

Initial temperature T1= 250 K

final Temperature T2= 350 K

initial volume V1 = ?

final volume V2 = 3.0 L

Solution:

This problem will be solved by Charles' Law equation at constant pressure

V1 / T1 = V2 / T2 . . . . . . . . (1)

put values in above equation

V1 / 250 K = 3.0 L / 350 K

Rearrange the above equation to calculate V1

V1 = (3.0 L / 350 K) x 250 K

V1 = (0.0086 L . K) x 250 K

V1 = 2.14 L

So the initial volume = 2.14 L

_________________

part 3

Data Given:

Initial temperature T1= 20 ºC

Convert Temperature from ºC to Kelvin

T = ºC + 273

T = 20 + 273 = 293 K

final Temperature T2= -5.00 ºC

Convert Temperature from ºC to Kelvin

T = ºC + 273

T = - 5.00 + 273 = 268 K

initial volume V1 = 2.35 L

final volume V2 = ?

Solution:

This problem will be solved by Charles' Law equation at constant pressure

V1 / T1 = V2 / T2 . . . . . . . . (1)

put values in above equation

2.35 L / 293 K = V2 / 268 K

Rearrange the above equation to calculate V1

V2 = (2.35 L / 293 K) x 268 K

V2 = (0.008 L . K) x 268 K

V2 = 2.15 L

So the volume at -5.00ºC = 2.15 L

6 0

4 years ago

How can radioactivity be used to help find the age of an object ?

gogolik [260]

Hope this answers your question Mariaduong159

Radiometric Dating. It's used to find the dates of ricks and other objects based on what the known decay rate of radioactive isotopes. Different forms of this method can also estimate the age of natural and man-made materials.

8 0

4 years ago