Answer:
This is a limitation of the kinetic-molecular theory.
Explanation:
Consider a cylinder of a gasoline engine at the beginning of the compression cycle, during which a fuel/air mixture (for our purposes mostly composed of nitrogen and oxygen, i.e. an ideal gas of diatomic molecules) at 300 K and 1 bar is compressed down to one-tenth volume (compression ratio of 10:1). Assume that the compression is rapid so no heat exchange occurs with the environment. Calculate the pressure and the temperature of the compressed gas. In a diesel engine the compression ratios are typically much higher; redo the same calculation with the compression ratio of 20:1.
Answer:
(i) Final pressure and temperature are 25.119 bar and 753.566 K, (ii) Final pressure and temperature are 66.289 bar and 994.336 K.
Explanation:
This system experiments an adiabatic compression, as such compression happens with no heat interaction between the piston-cylinder device and surroundings. This is a particular case of polytropic process, in which there is no entropy generation according to the Second Law of Thermodynamics.
The compression process is represented by the following formulas:
[tex]\frac{p_{2}}{p_{1}} = \left(\frac{V_{1}}{V_{2}} \right) ^{\gamma}[/tex] (Eq. 1)
[tex]\frac{T_{2}}{T_{1}} = \left(\frac{V_{1}}{V_{2}} \right)^{\gamma - 1}[/tex] (Eq. 2)
Where:
[tex]p_{1}[/tex], [tex]p_{2}[/tex] - Initial and final pressures, measured in bar.
[tex]T_{1}[/tex], [tex]T_{2}[/tex] - Initial and final temperatures, measured in Kelvins.
[tex]V_{1}[/tex], [tex]V_{2}[/tex] - Initial and final volumes, measured in cubic meters.
[tex]\gamma[/tex] - Specific heat ratio of air, dimensionless.
From Theory of Diesel and Otto Cycles we know that compression ratio is defined as:
[tex]r_{c} = \frac{V_{1}}{V_{2}}[/tex] (Eq. 3)
And (Eqs. 1, 2) can be rewritten as follows:
[tex]\frac{p_{2}}{p_{1}} = r_{c}^{\gamma}[/tex] (Eq. 1b)
[tex]\frac{T_{2}}{T_{1}} = r_{c}^{\gamma - 1}[/tex] (Eq. 2b)
Then, we clear final pressure and pressure in each expression and calculate them for each case:
[tex]p_{2} = p_{1}\cdot r_{c}^{\gamma}[/tex]
[tex]T_{2} = T_{1}\cdot r_{c}^{\gamma-1}[/tex]
(i) [tex]r_{c} = 10[/tex], [tex]p_{1} = 1\,bar[/tex], [tex]T_{1} = 300\,K[/tex], [tex]\gamma = 1.4[/tex]
[tex]p_{2} = (1\,bar)\cdot 10^{1.4}[/tex]
[tex]p_{2} = 25.119\,bar[/tex]
[tex]T_{2} = (300\,K)\cdot 10^{0.4}[/tex]
[tex]T_{2} = 753.566\,K[/tex]
Final pressure and temperature are 25.119 bar and 753.566 K.
(ii) [tex]r_{c} = 20[/tex], [tex]p_{1} = 1\,bar[/tex], [tex]T_{1} = 300\,K[/tex], [tex]\gamma = 1.4[/tex]
[tex]p_{2} = (1\,bar)\cdot 20^{1.4}[/tex]
[tex]p_{2} = 66.289\,bar[/tex]
[tex]T_{2} = (300\,K)\cdot 20^{0.4}[/tex]
[tex]T_{2} = 994.336\,K[/tex]
Final pressure and temperature are 66.289 bar and 994.336 K.
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Answer:
D. Atom, Electron, and Proton
Explanation:
Because Atoms are the smallest and they make up everything.
because the Proton, stable subatomic particle that has a positive charge equal in magnitude to a unit of electron charge and a rest mass of 1.67262 × 10−27 kg, which is 1,836 times the mass of an electron.
Answer:
C
Explanation:
Electrons are the smallest part of matter. Protons are bigger than electrons. And the whole atom is bigger than everything inside it.
Is crumbling a cookie, a physical change? Explain why. My child is having problems with this question, and I'm not so sure how to explain it.
Answer:
Because the sugar flour and eggs can no longer be separated. The properties of the materials have changed so it's a chemical change
Sugar, flour, and eggs cannot be separated. The materials' properties have changed, resulting in a chemical change.Therefore, crumbling a cookie is not a physical change.
What is physical change ?Physical changes affect a chemical substance's form but not its chemical composition. Physical changes can be used to separate mixtures into their component compounds, but not to separate compounds into chemical elements or simpler compounds.
A chemical change is the transformation of one material into another, the formation of new materials with different properties, and the formation of one or more new substances. It occurs when one substance reacts with another to form a new substance.
A physical change is characterized by a change in physical properties. Melting, transition to a gas, change in strength, change in durability, changes in crystal form, textural change, shape, size, colour, volume, and density are all examples of physical properties.
Thus, crumbling a cookie is not a physical change.
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Calculate the number of atoms in a 3.68×103 g sample of aluminum.
Answer:
84.23×10^23
Explanation:
no.of atoms =given wt / gram Mw×avagdro num
Can someone suggest some really good scientific topic for my scientific presentation?
Question 4 of 8
What can cause an object to move?
A. Balanced forces
B. Unbalanced forces
C. Inertia
D. A reference point
SUER
Answer:
unbalanced forces can cause an object to move.
Answer:
Unbalanced Forces
Explanation:
Where is ionization energy highest on the periodic table?
What type of gases would be in the top right?
Ionization levels are most highest on the top right side of the Periodic Table. The type of gases that would be in the top right are noble gases, like helium, and other common noble gases.
Hope this answer helps you!
Are strong acids more readily attracted to strong bases than to weak bases?
Jack was playing with a toy car and a track that records velocity over time using sensors and it generated the graph below:
At which points on the graph is the car showing acceleration?
Group of answer choices
Sections a, c, and d
Sections a, b, c, and d
Sections a and d
Section a only
Answer:
a,c, and d
Explanation:
if velocity is not a flat line, that means there is acceleration, whether it is positive or negative acceleration.
butter melting on warm pancakes is
conduction
convection
radiation
butter melting on warm pancakes is convection
The following information should be considered:
Since convection is the movement arise within a fluid by the tendency of hotter and therefore less dense material to rise,.Moroever, it is colder, denser material to sink under the impact of gravity, that leads in transfer of heat.learn more: https://brainly.com/question/2514933?referrer=searchResults
How many electrons are in the highest occupied energy level, n, of an element in Group 15?
Answer:
5 Electrons.
Explanation:
Hello.
In this case, an element in group 15 such as nitrogen has 5 electrons on the outer shell because of its electron configuration. For N, whose atomic number is 7, the electron configuration is:
[tex]N^7: 1s^2,2s^2,2p^3[/tex]
Whereas energy level 2 has 5 electrons (2 from 2s and 3 from 2p). Next element is phosphorous and its electrons configuration is:
[tex]P^{15}:1s^2,2s^2,2p^6,3s^2,3p^3[/tex]
It also has 5 electron on the energy level 3 (2 from 3d and 3 from 3p).
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helppp What function does adding a coefficient in a chemical equation serve?
Coefficients cannot be added or changed without describing different substances.
It tells whether the reactants must be exposed to outside factors to make them react.
It balances the equation, ensuring each side of the reaction has an equal number of atoms.
It describes the physical state of the reactant or product to which it is attached.
Answer: The answer is option C. (It balances the equation, ensuring each side of the reaction has an equal number of atoms.)
Explanation:
With regard to Lewis structures, what is the importance of the octet rule?A. Orbitals fill one electron at a time.
B. All elements contain eight electrons at all times.
C. Elements with less than eight valence electrons are reactive.
D. No more than two electrons can share an orbital.
What does Newton’s first law of motion state?
Answer:
Newton's first law states that every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. This is normally taken as the definition of inertia. ... If that velocity is zero, then the object remains at rest.
Explanation:
Answer:
Before Galileo and Newton, many people thought that objects lost speed because they had a built-in natural tendency to do so. But those people weren't taking into account the multiple forces here on Earth - for example, friction, gravity, and air resistance - that cause objects to change their speed. If we could see the motion of an object in deep interstellar space, we would be able to observe the natural tendencies of an object that is free from any external influence. In deep interstellar space we would observe that if an object had a speed, it would continue to move with that speed until there was some force causing a change in its motion. Likewise, if an object were at rest in interstellar space, it would remain at rest until there was a force causing a change in its motion.
Explanation:
Hope it helped you =)
Which type of investigation is based on observation?
Answer:
Quantitative Observations
Explanation:
What is the current atomic model called?
Answer:
Quantum Mechanical
Explanation:
This current atomic model evolved from the earlier Rutherford-Bohr model, which compared electrons orbiting an atomic nucleus to planets orbiting the sun. The newest understanding of atomic makeup in the Electron Cloud Model better represents observed atomic phoneme since the Bohr model rose to prominence.
Answer:
Electron cloud model
Explanation:
Question 4 (1 point)
Neon gas is often used to make signs for restaurants and businesses. However, neon only accounts
for 0.0018% of Earth's atmosphere. Scientists are looking for other elements that have similar
properties as neon that could be used as a substitute. Which of the following elements would most
likely be a good substitute?
Oь
Argon
Flourine
Chlorine
Oxygen
d
Submit
Submit
Answer:
Argon
Explanation:
The element that would most likely be a good substitute for neon is "argon".
These two elements belong to the noble gases in Group 18(8A) of the Periodic Table. They are inert gases - they do not react chemically with other substances.
Argon, as an inert gas is often used whenever an inert atmosphere is needed. Argon is used in incandescent light bulbs. It is used to stop oxygen from corroding the filament. It is also used by welders to protect weld area.
Argon is a good substitute for neon in this context because they possess some physical properties which are similar.
How do conduction and convection differ? (4 points)
Conduction can move through empty space to transfer heat; convection cannot.
Conduction does not require objects to have direct physical contact; convection does.
Conduction requires objects to have direct physical contact; convection does not.
Conduction transmits heat through electromagnetic waves; convection does not. PLS HELP
Conduction is the transfer of thermal energy through direct contact. Convection is the transfer of thermal energy through the movement of a liquid or gas.
So I think you should go with the 3rd option.
Hope this was helpful.
Answer:
What the other guy said
Explanation:
All matter has thermal energy because atoms are constantly
All matter has thermal energy because atoms are constantly in motion, due to motion all matter possess a kinetic energy. The total kinetic energy is known as thermal energy.
What is kinetic energy?The kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes
Thermal energy and temperature are closely related. Both reflect the kinetic energy of moving particles of matter. However, temperature is the average kinetic energy of particles of matter, whereas thermal energy is the total kinetic energy of particles of matter.
It increases or decreases only when the velocity changes, heavier objects, It can transform into other types of energy. It will occur regardless of the moving object's direction of travel.
Thus, all matters has thermal energy because atoms are constantly in motion.
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Explain the difference between the reactants and
products of a chemical reaction.
3
Answer:
:)
Explanation:
The substance(s) to the left of the arrow in a chemical equation are called reactants. A reactant is a substance that is present at the start of a chemical reaction. The substance(s) to the right of the arrow are called products . A product is a substance that is present at the end of a chemical reaction.
What are the physical properties of chlorine?
Answer:
The Physical Properties of Chlorine are as follows:
Color: Greenish-yellow.
Phase: Gas.
Odor: Disagreeable, suffocating smell.
Density: About two and one-half times as dense as air.
Solubility: Is soluble in water. ...
Boiling Point: The boiling point of chlorine is –34.05°C.
Melting Point: The melting point is –101°C.
Explanation:
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Identify the results of a substance losing enegry
Why can't silver have a mass number of 107.87?
Answer:
Silver does have a mass of 107.87.
Explanation:
You are asked to devise a procedure for quality control in a fertilizer plant to check that the nitrogen and phosphorus content is within a specified range. You decide on the outlined steps to monitor a production run of 1000 bags of fertilizer. A. A 50 g sample is removed from every 100th bag of fertilizer produced, resulting in ten 50 g samples. B. Samples 1, 3, 5, 7, and 9 are thoroughly mixed and a 50 g sample of the mixture is removed. C. Samples 2, 4, 6, 8 and 10 and the 50 g sample from the mixture are taken to the analytical laboratory. D. Each 50 g sample is separately dissolved in a fixed volume of water and the solution is filtered to determine the quantity of insoluble material. E. Separate aliquots of the water solutions are subjected to the procedures of phosphorus and nitrogen analysis.
Answer:
Options : A, B and C are correct procedure for quality control in a fertilizer plant
Explanation:
The options that constitute the sampling plan are :
A) A 50 g sample is removed from every 100th bag of fertilizer produced, resulting in ten 50 g samples
B) Samples 1, 3, 5, 7, and 9 are thoroughly mixed and a 50 g sample of the mixture is removed
C) Samples2,4,6,8 and 10 and the 50 g sample from the mixture are taken to the analytical laboratory.
A quality control procedure is used to ensure that a certain product is produced following set standards or meets the required quality desired by the customer . and options A, B and C ensures that.
An obligation to do something or control over or care for someone.
Answer: a responsibilty
Explanation:
An obligation to do something or control over or care for someone. The word suitable for it is "responsibility".
An obligation is a duty or responsibility to do anything that is required by law, custom, or moral standards.
Responsibility is an obligation to do something or control over or care for someone. It is a duty or task that one is required to undertake.
Responsibility can be of different forms, such as personal, social, or professional.
Personal responsibility refers to the responsibility that an individual has for their own actions and decisions.
Social responsibility refers to the responsibility that an individual or organization has to act in the best interest of society.
Professional responsibility refers to the responsibility that individuals have to perform their job duties to the best of their ability.
Therefore, the term most suits for the given statement is "responsibility".
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what is extraction .....???
Answer:
Extraction is the action of removing something.
Explanation:
The oxidation number that the Alkaline Earth Metals normally have when forming compounds is
Answer:
+2
Explanation:
All the alkaline earth metals have 2 valence electrons in their valence shell. Therefore, they lose 2 electrons to form cations with a +2 charge. For example, Mg²⁺.
Hope that helps.
A venus fly trap snaps shut when a fly lands on the trigger hairs inside its trap.
Which characteristic of life does this represent?
reproduction
A. cell organization
B. heredity
C. response to environment
Answer:
C. Response to environment
Do not use cords, and do not plug in many devices into one power source
Calculate the mass of a sample of fruit sugar, fructose,
C6H1206, containing 2.65 X 1020 molecules.
Answer:
, containing 2.65 X 1020 molecules.
Explanation:
The mass of a sample of fruit sugar (fructose) C₆H₁₂O₆, containing 2.65 ×10²⁰ is equal to 2.88 g.
What is Avogadro's number?Avogadro’s number can be defined as the number of units in one mole of any chemical substance. Generally, these entities can be electrons, molecules, atoms, ions, or protons, depending upon the kind of chemical reaction or reactants and products.
The value of Avogadro’s constant is found approximately 6.022 × 10²³ mol⁻¹.
Given, the number of molecules of fructose = 2.65 ×10²⁰
The molar mass of the fructose = 180.16 g/mol
So 6.022 × 10²³ molecules of fructose have mass = 180.16 g
Then 2.65 × 10²⁰ fructose molecules will have mass = 2875.04 × 10⁻³ g
The mass of the 2.65 × 10²⁰ fructose molecules = 2.88 g
Therefore, the mass of 2.65 × 10²⁰ fructose molecules is equal to 2.88 g.
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