At room temperature (20 °C), milk turns sour in about 64 hours. In a refrigerator at 3 °C, milk can be stored three times as long before it sours.
(a) Estimate the activation energy of the reaction that causes the souring of milk.
(b) How long should it take milk to sour at 40 °C?

Answers

Answer 1

Answer: Since k2 corresponds to 64 hours, the time for the milk to sour at 40 C is 64 h / 9.38 = 6.8 hours.

Explanation:

At temperature T1, the Arrhenius Equation is:

k1 = Ae^(-Ea/RT1).

An equivalent equation can be written at T2:

k2 = Ae^(-Ea/RT2).

If these equations are divided, then A cancels:

k1/k2 = e^(-Ea/RT1)/e^(-Ea/RT2)

Taking the natural log:

ln(k1/k2) = (Ea/RT2)-(Ea/RT1);

or:

ln(k1/k2) = (Ea/R)(1/T2 - 1/T1)

We can infer from the question that the milk sours 3 times as fast at the higher temperature (let's call it T1), so we can arbitrarily call k2 = 1 and k1 = 3.

a) Substitute:

ln(3) =  (Ea/R)(1/276.15 K - 1/293.15 K).

We get Ea/R = 5231.6. Multiply this by whatever value of R you choose to get Ea in your favorite energy unit. Remember the sig figs.

b) Again, let's let the lower temperature = T2, since we have defined k2 = 1:

ln(k1) = (5231.6)(1/276.15 K - 1/313.15);

ln(k1) = 2.24, so k1 = 9.38.

Since k2 corresponds to 64 hours, the time for the milk to sour at 40 C is 64 h / 9.38 = 6.8 hours.


Related Questions

A saturated hydrocarbon having molecular formula CnH2n+2 diffuses through a porous membrane twice as fast as sulphur dioxide. Calculate the volume occupied by the hydrocarbon at27°C and 2atm ?
Help me fast !​

Answers

Answer:

12.3 L

Explanation:

Now we have that the rate of diffusion of the saturated hydrocarbon is R1

Rate of diffusion of sulphur dioxide is R2

Molar mass of hydrocarbon is M1

Molar mass of sulphur dioxide is 64 gmol-1

From Graham's law;

R1/R2 = √64/M1

2/1 =√64/M1

(2/1)^2 = (√64/M1)^2

4/1 = 64/M1

4M1 =64

M1 = 16

To obtain the number of moles of the gas;

(n*12) + (2n + 2) 1 = 16

12n + 2n + 2 = 16

14n + 2 = 16

14n = 16 - 2

n = 14/14

n = 1

Hence the hydrocarbon is CH4

Volume occupied by CH4 at STP = 22.4 L

Hence;

P1 = 1 atm

T1 = 273 K

V1 = 22.4 L

T2 = 300 K

P2 = 2 atm

V2 = ?

P1V1/T1 = P2V2/T2

P1V1T2 = P2V2T1

V2 = P1V1T2/P2T1

V2 = 1 * 22.4 * 300/2 * 273

V2 = 12.3 L

The volume occupied by the hydrocarbon at 27 °C and 2 atm is 12.31 L

Let the hydrocarbon be initially at standard temperature and pressure (STP)

Thus, we can obtain the new volume of the hydrocarbon by using the combined gas equation as illustrated below:

Initial volume (V₁) = STP = 22.4 L Initial pressure (P₁) = STP = 1 atmInitial temperature (T₁) = STP = 273 KFinal temperature (T₂) = 27 °C = 27 + 273 = 300 KFinal pressure (P₂) = 2 atmFinal volume (V₂) =?

P₁V₁ / T₁ = P₂V₂ / T₂

(1 × 22.4) / 273 = (2 × V₂) / 300

22.4 / 273 = (2 × V₂) / 300

Cross multiply

273 × 2 × V₂ = 22.4 × 300

546 × V₂ = 6720

Divide both side by 546

V₂ = 6720 / 546

V₂ = 12.31 L

Thus, the volume occupied by the hydrocarbon at 27 °C and 2 atm is 12.31 L

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A radical is a reactive intermediate with a single ____________ electron, formed by ____________ of a covalent bond. Allylic radicals are stabilized by ____________ , making them ____________ stable than tertiary radicals. A compound that contains an especially weak bond that serves as a source of radicals is called a radical ____________ . Treatment of cyclohexene with N-bromosuccinimide in the presence of light leads to ____________ by ____________ intermediates.

Answers

1. A radical is a reactive intermediate with a single ____________ electron, formed by ____________ of a covalent bond.

1. A: Unpaired, and homolysis

2. Allylic radicals are stabilized by ____________ , making them ____________ stable than tertiary radicals.

2. A: Resonance, and more

3. A compound that contains an especially weak bond that serves as a source of radicals is called a radical ____________ .

3. A: Initiator

4. Treatment of cyclohexene with N-bromosuccinimide in the presence of light leads to ____________ by ____________ intermediates.

4. A: Allylic substitution by radical

What is another name for acetic acid? *
1. lemons, limes or oranges
2 .vinegar
3. vitamin C

Answers

It’s not b because vinegar is no less than 4%. Most likely it’s C but I’m not sure if you do choose C let me know if I’m wrong or right. Good luck !

How are the three intermolecular forces related?

Answers

Explanation:

Intermolecular forces are electrostatic in nature and include van der Waals forces and hydrogen bonds. ... The three major types of intermolecular interactions are dipole–dipole interactions, London dispersion forces (these two are often referred to collectively as van der Waals forces), and hydrogen bonds.May 20, 2018

In the reaction C + O2 → CO2, 18 g of carbon react with oxygen to produce 72 g of carbon dioxide. What mass of oxygen would be needed in the reaction?

18 g
54 g
72 g
90 g

Answers

Answer:

54g of O2 reacted in the reaction

Answer:

54g

Explanation:

Molecular orbital diagram for Fe.

Answers

ANSWER;

1s22s22p63s23p63d64s2

EXPLANATION;

Molecular orbital diagram for Fe.

In writing the electron configuration for Iron the first two electrons will go in the 1s orbital. Since 1s can only hold two electrons the next 2 electrons for Iron go in the 2s orbital. The next six electrons will go in the 2p orbital. The p orbital can hold up to six electrons. We'll put six in the 2p orbital and then put the next two electrons in the 3s. Since the 3s if now full we'll move to the 3p where we'll place the next six electrons. We now shift to the 4s orbital where we place the remaining two electrons. After the 4s is full we put the remaining six electrons in the 3d orbital and end with 3d6.

Therefore the Iron electron configuration will be 1s22s22p63s23p64s23d6.

Note that when writing the electron configuration for an atom like Fe, the 3d is usually written before the 4s. Both of the configurations have the correct numbers of electrons in each orbital, it is just a matter of how the electronic configuration notation is written

Therefore we have 1s22s22p63s23p63d64s2

Your skin is an important organ and has several functions. All of the functions below are performed by the skin EXCEPT
A)
makes vitamin D.
B
prevents-dehydration:
C)
maintains body temperature.
D)
works with bones to help you move.

Answers

Answer:D

Explanation:

Your skin makes vitamin D

Your skin prevents dehydration

And your skin maintains body temperature. So you are left with D

Answer:

The correct option is D.

works with bones to help you move

Explanation:

Skin is the outer layer of the body and it is the body's largest organ.

It protect the body from heat and other harmful substances.

It is comprises of three layers;

The Epidermis which is the outer layer.

The dermis which is a fibrous later that protect the Epidermis.

The subcutis is the subcutaneous layer that is beneath the dermis.

Function of the skin.

1. It's regulate body temperature

2. It's protect the body from heat and pathogenic entry.

3. It produces vitamin D

4. The skin allow sensations or feelings of touch, heat, and cold.

Therefore;

works with bones to help you move is wrong because it is the muscle that work with the bone.

What element needs just a single extra electron to have the same electron configuration as helium?​

Answers

Answer:

Hydrogen

Explanation:

Helium has an atomic number Z = 2, that is, it has 2 protons. Since it is electrically neutral it also has 2 electrons. Thus, the electron configuration of helium is 1s².

Hydrogen has an atomic number Z = 1, that is, it has 1 proton. Since it is electrically neutral it also has 1 electron. Thus, the electron configuration of hydrogen is 1s¹.

If hydrogen gains a single extra electron to form H¹⁻, it acquires the same electron configuration than helium.

A different brand of iron tablet was analysed by Hitration with 0.0093 mol.L" potassium
dichromate via the reaction listed below;
Cr2O72- + 6Fe2+ + 14H+ + 2Cr3+ + 6Fe3+ + 7H20
In this experiment 4 tablets were crushed and dissolved in 200 cm3 of dilute acid. 25cm3
of this solution was used in the titration. The results of the titrations were as follows;
Titration Volume dichromate (cm)
1
33.0
2
32.05
3
32.15
4
32.10
Calculate the concentration of iron used in the titration (4 dp).
C1V1/C2V2 = n/n2

Answers

The concentration of iron used in the titration : 0.009 M

Further explanation

Given

Reaction

Cr₂O₇²⁻ + 6Fe²⁺ + 14H⁺ ⇒ 2Cr³⁺ + 6Fe³⁺ + 7H₂O

0.0093 mol/L potassium  dichromate

200 cm³ of dilute acid, 25cm³   was used in the titration.

Required

the concentration of iron

Solution

Titration formula

C₁V₁n₁=C₂V₂n₂⇒ From equation : n₁=6n₂(1=Cr₂O₇, 2=Fe)

titration average : 33+32.05+32.15+32.1 / 4 = 32.325 cm³(ml)

25 cm³ of iron solution used in titration :

[tex]\tt V_1=32.325~ml\\\\V_2=25~ml\\\\C_1=0.0093~M\\\\\\\\C_1.V_1.n_2=C_2.V_2.n_1\\\\0.0093\times 32.325\times 6=C_2\times 25\times 1\\\\C_2=0.07215~M[/tex]

Dilution(25 ml from 200 ml iron solution)

[tex]\tt C_2.V_2=C_1.V_1\\\\0.007215\times 25=C_1\times 200\\\\C_1=0.009~M[/tex]

which 2 not one 2! hjmdnxhjund

Answers

Answer:

A and D then I guess

Explanation:

sorry hope this helps!

Read the word equation: “Propane gas plus oxygen gas produces __________.”
b) Convert the word equation to a chemical equation and complete the reaction. Be sure to balance
the chemical equation.
c) Record the balanced chemical equation on the Student Worksheet.

Answers

Answer:

Propane gas plus oxygen gas produces water and carbon dioxide.

Explanation:

This is the initial chemical equation: C3H8 + O2 = CO2 + H2O

This is the balanced chemical equation: C3H8 + 5 O2 = 3 CO2 + 4 H2O

Propane gas plus oxygen gas produces carbon dioxide and water. The balanced chemical equation is as follows: C3H8 + 5O2 → 3CO2 + 4H2O

Propane is a member of the alkane group with the chemical formula; C3H8 while oxygen gas has the chemical formula; O2.

Propane gas (C3H8) and oxygen gas (O2) combines to produce carbon dioxide (CO2) and water (H2O).

The chemical equation is as follows:

C3H8 + O2 → CO2 + H2O

However, the above equation is not balanced. To balance it, we make use of coefficients to make the number of atoms of each element equal.

The balanced equation is as follows:

C3H8 + 5O2 → 3CO2 + 4H2O

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HELP DUE MONDAY!!
Don’t understand

Answers

Answer:

Concept: Chemical Analysis

You need to start by graphing the data and then analyzing it.We can see that the horse has a distance in meters of 980 at the end of the 10 seconds hence it is the fastest.The horse line has a linearly representation, while the alternate line has parabolic tendencies towards the end. The steeper line indicates a faster change in time or velocity which results in a greater distance traveled indicating that the horse is faster.*I have confidence you can graph that*

How is the kinetic energy of the particles of a substance affected during a phase change?
A.) Kinetic energy increases during exothermic changes and decreases during endothermic changes.
B.) Kinetic energy decreases during exothermic changes and increases during endothermic changes.
C.) Kinetic energy does not change, but the potential energy does.
D.) Kinetic energy changes in the opposite way that the potential energy changes.

Answers

Answer: A. Kinetic energy increases during exothermic changes and decreases during endothermic changes

Explanation: During an exothermic change potential energy is converted to kinetic energy. I hope this is correct. :)

Answer:

C

Explanation:

How long does it take for the moon to make one revolution around Earth?

Answers

Answer:

27 days, 7 hours and 43 minutes.

Explanation:

To complete a full orbit around Earth, it takes 27 days, 7 hours and 43 minutes for the Moon. This is called sidereal month and is measured by the Moon's position relative to distant *fixed" stars.

The density of a gas is 1.26 g/L at STP. What is the mass of 1 mole? What could this gas be?

Answers

Answer: Molar mass=28.224g/mol, The gas could be Nitrogen gas

Explanation:

Density is calculated as  Molar mass/ Molar Volume

Recall that

One mole of an ideal gas at (STP) standard temperature and pressure = 22.4 liters (in Volume)

Given That Density =1.26 g/L

Volume = 22.4L at STP,

Molar mass = Density x Molar Volume

= 1.26 g/L x 22.4L =28.224g

Therefore, if  1  mole of this gas has a mass of 28.224g  then  its molar mass is equal to 28.224g/mol

The molar mass of Nitrogen =  28.014 g/moL, so we can conclude the the gas could be Nitrogen

Which statement is true about copper and salt?

Answers

Well there aren’t any statements but, Salt and Copper are pure substances they aren't a part of a mixture on their own I hope this helps

why is it important to prepare for disaster? what are the things you need to prepare?​

Answers

Explanation:

The reason why it is important to prepare for an disaster is because Being prepared can reduce fear, anxiety, and losses that accompany disasters. People also can reduce the impact of disasters (flood proofing, elevating a home or moving a home out of one's harm's way, and securing items that could shake loose in an earthquake) and sometimes avoid the danger completely.

The things you need to prepare for an disaster is

WaterFoodClothing Money if neededFlash lightBatteriesFirst aid kitYou can even need an radio( to keep updated).

HELP 20 POINTS

What is the frequency of an Electromagnetic wave has with wavelength 2.94 x 10^-8 cm?

Answers

The answer is 30.84

Please help Fast I do not know

Answers

Answer:

So the answer to this question would be C. 400 J

Explanation:

Now for this problem, what is given is a 40 Newtons which would represent the force to be applied to the object, and a distance of 10 meters after the application of the said force. When these two combine, work is done. The unit for work is Joules and this is what we are looking for. The formula to get Joules or for work would be the force applied to the object multiplied by the distance that it travelled after the application of the force. It looks like this

work = force x distance

Joules = Newtons x meter

so let us substitute the variables to their corresponding places

Joules = 40 N x 10 m

Joules = 400 J

IF THIS HELPED YOU PLEASE MARK ME BRAINLIEST! THANKS! :)))))

How many grams of water will be produced when 1.6 moles of ethanol (CH3CH2OH) are burned completely? Enter a number only (no units) and express your answer using the correct number of significant figures.

Answers

Answer:

86

Explanation:

The reaction that takes place is:

C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O

First we convert moles of ethanol to moles of water:

1.6 mol ethanol * [tex]\frac{3molH_2O}{1molEthanol}[/tex] = 4.8 mol H₂O

Then we convert moles of water to grams of water, using its molar mass:

4.8 mol H₂O * 18 g/mol = 86.4 g

So 84.6 grams of water will be produced.

The mass of water, H₂O produced when 1.6 moles of ethanol, C₂H₅OH are completely burned is 86.4 g

We'll begin by writing the balanced equation for the reaction. This is given below

C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O

From the balanced equation above,

1 mole of C₂H₅OH reacted to produce 3 moles of H₂O.

Next, we shall determine the number of mole of H₂O produced by the reaction of 1.6 moles of C₂H₅OH

From the balanced equation above,

1 mole of C₂H₅OH reacted to produce 3 moles of H₂O.

Therefore,

1.6 moles of C₂H₅OH will react to produce = 1.6 × 3 = 4.8 moles of H₂O.

Finally, we shall determine the mass of 4.8 moles of H₂O.

Mole of H₂O = 4.8 moles

Molar mass of H₂O = (2×1) + 16 = 18 g/mol

Mass of H₂O =?

Mass = mole × molar mass

Mass of H₂O = 4.8 × 18

Mass of H₂O = 86.4 g

Thus, the mass of water obtained from the reaction is 86.4 g

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Please help will give brainliest

Answers

Answer:

the answer id D

Explanation:

i dont know im just living here 5

Spheres of Earth Assignment Active Analyzing Sphere Interactions Explain how Earth's spheres may be affected by the droughts brought on by El Niño. Sometimes, the surface of the Pacific Ocean warms up, causing changes in the weather in some areas. This phenomenon is called El Niño. El Niño causes the amount of rainfall in some parts of the United States and South America to increase. It also causes droughts to occur in Southeast Asia and Australia. Droughts occur when an area receives less rain than it normally does over a certain period.


help me on this question please. it is 7th grade science​

Answers


During El Niño, changes in wind and ocean current patterns result in warm waters stretching across the whole Pacific Ocean. This extra heating causes changes in wind patterns, which causes atmosphere to react and change all the way from the ground to the edge of space around Earth.

In a molecule of calcium sulfide, calcium has two valence electron bonds, and a sulfur atom has six valence electrons. How many lone pairs of electrons are present in the Lewis structure of calcium sulfide?
A. one
B. two
C. three
D. four
E. none

Answers

Answer:

E.none

Explanation:

because the bonds join with each other and no lone pair is left

17. What is the correct empirical formula for H4C408?
A
H2C204
B HCO2
C
HCO4
D
H2C202

Answers

Answer:

B

Explanation:

by simlfying it you get HCO2

what tools are used specifically for earth science

Answers

Geologic Tools. Geologists use a lot of tools to aid their studies. Some of the most common tools used are compasses, rock hammers, hand lenses, and field books.

hope this helped <3

Pieces of DNA that pass genetic traits from parent to offspring

A. Phenotype
B. Gene
D. Allele

Answers

Answer:

gene

Explanation:

Which of these sentences probably comes from a work of classic literature?) PLEASE HELP ILL GIVE YOU BRAINLEIST!


A. The greedy man was harsh as winter, and had never done a generous deed in his long life; he was a hermit.
B. The man who refused to share with those in need had never felt the warmth that comes from giving.
C. The most selfish man in town was one who lived alone and never had visitors of any sort, except maybe lawyers.
D. The miser was hard and sharp as flint, from which no steel had ever struck out generous fire; he was as solitary as an oyster.

Answers

The sentences that probably comes from a work of classic literature are:

The most selfish man in town was one who lived alone and never had visitors of any sort, except maybe lawyers. The miser was hard and sharp as flint, from which no steel had ever struck out generous fire; he was as solitary as an oyster.

What types of books are regarded as classics?

The great literary works of Greek, Roman, and other prehistoric civilizations are referred to as classical literature. Classical literature includes the writings of Homer, Ovid, and Sophocles. The phrase isn't just applicable to books. It can also incorporate other types of writing, such as epic, lyric, tragedy, comedy, and pastoral.

Classical literature enables us to take a profound plunge into the lives, worldviews, and mindsets of individuals we have never met, to travel to unfamiliar settings, and to comprehend eras we will never be able to experience ourselves.

Therefore, option C and D are correct.

Learn more about literature at:

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#SPJ1

Describe the characteristics
of the different sections
(families) of the periodic
table

Answers

Answer: The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods

What does a useful scientific explanation include ??

Answers

Answer: scientific explanation

Explanation:

A really good scientific explanation should do two main things: It should explain all the observations and data we have. It should allow us to make testable predictions that we can check using future experiments.

can someone help me with my chemistry on my page/account?

Answers

Answer:

Yes

Explanation:

Text me on here

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