Imagine you have three tuning forks of frequencies 250, 500 and 1000 Hz. Which one would:
A) sound the lowest
B) have the highest pitch

The average rate of reaction for the given time interval of 0 s to 205 s is calculated out to be -0.00088 M/s.

To calculate the average rate of reaction for each successive time interval, we need to use the formula:

Average rate of reaction = (Change in concentration) / (Change in time)

For the time interval from 0 s to 50 s, the change in concentration is (0.42 M - 0.50 M) = -0.08 M, and the change in time is (50 s - 0 s) = 50 s. Therefore, the average rate of reaction is:

Average rate of reaction = (-0.08 M) / (50 s) = -0.0016 M/s

Similarly, we can calculate the average rate of reaction for each successive time interval as follows:

----------------------------------------------------------------------------------------------------------

Time interval  Change in concentration Change in time Average    

                                                                                                 rate of reaction

----------------------------------------------------------------------------------------------------------

0 s to 50 s        -0.08 M                        50 s                  -0.0016 M/s

50 s to 100 s        -0.06 M                        50 s              -0.0012 M/s

100 s to 150 s               -0.05 M                       50 s                    -0.0010 M/s

150 s to 200 s       -0.05 M                       50 s                   -0.0010 M/s

200 s to 250 s       -0.04 M                       50 s                   -0.0008 M/s

----------------------------------------------------------------------------------------------------------

To find the average rate of reaction for the time interval from 0 s to 205 s, we need to add up the changes in concentration and divide by the total change in time:

Average rate of reaction = (-0.08 M - 0.06 M - 0.05 M - 0.05 M - 0.04 M) / (205 s - 0 s) = -0.00088 M/s

Therefore, the average rate of reaction for the time interval from 0 s to 205 s is -0.00088 M/s.

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The complete question is :

The following table shows the concentration of a reactant at various times during a chemical reaction. Calculate the average rate of reaction for each successive time interval. What is the average rate of reaction for the time interval from 0 s to 205 s?

Time (s)         Concentration (M)

0                     0.50

50                     0.42

100                     0.36

150                     0.31

200                     0.26

250                     0.22

Answer:

7 km/hr

Explanation:

rate = distance / time

Rate: in km/hr

Distance: 14 km

Time: 2 hr

Rate = 14 km / 2 hr

Rate = 7 km/hr

The molarity of a solution made by dissolving 51.6 grams of NaCl in enough water to make 650 ml of solution  is approximately 1.36 M

The molarity of a solution can be calculated using the formula:

Molarity (M) = (moles of solute) / (volume of solution in liters)

First, we need to convert the mass of NaCl (51.6 grams) to moles. To do this, we'll use the molar mass of NaCl, which is approximately 58.44 g/mol.

Moles of NaCl = (51.6 grams) / (58.44 g/mol) = 0.883 moles

Next, we'll convert the volume of the solution from milliliters (mL) to liters (L).

Volume of solution = 650 mL * (1 L / 1000 mL) = 0.65 L

Now, we can calculate the molarity of the solution using the formula.

Molarity (M) = (0.883 moles) / (0.65 L) = 1.36 M

Thus, the molarity of the solution made by dissolving 51.6 grams of NaCl in enough water to make 650 mL of solution is approximately 1.36 M (rounded to two decimal places).

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Charles's Law-

[tex]\:\:\:\:\:\: \:\:\:\:\:\:\star\longrightarrow\sf \underline{\dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}}\\[/tex]

Where:-

As per question, we are given that -

We are given the initial temperature and the final temperature in °C.So, we first have to convert those temperatures in Celsius to kelvin by adding 273-

[tex]\:\:\:\:\:\:\star\sf T_1[/tex] = 50+ 273 = 323K

[tex]\:\:\:\:\:\:\star\sf T_2[/tex] =150+273 = 423K

Now that we have obtained all the required values, so we can put them into the formula and solve for V₁:-

[tex]\:\:\:\:\:\: \:\:\:\:\:\:\star\longrightarrow\sf \underline{\dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}}\\[/tex]

[tex] \:\:\:\:\:\:\:\:\:\:\:\:\longrightarrow \sf V_1 = \dfrac{V_2}{T_2}\times T_1\\[/tex]

[tex] \:\:\:\:\:\:\:\:\:\:\:\:\longrightarrow \sf V_1 = \dfrac{175}{423}\times 323\\[/tex]

[tex] \:\:\:\:\:\:\:\:\:\:\:\:\longrightarrow \sf V_1 = 0.41371......\times 323\\[/tex]

[tex]\:\:\:\:\:\: \:\:\:\:\:\:\longrightarrow \sf V_1 = 133.628........\\[/tex]

[tex] \:\:\:\:\:\:\:\:\:\:\:\:\longrightarrow \sf\underline{ V_1 = 133.63 mL}\\[/tex]

Therefore, the original volume ( Initial volume) of neon is 133.63mL.

1. The C in the first structure should have four total valence electrons. To complete its octet, it thus requires 4 extra electrons. The molecule should thus have 8 + 2 = 10 valence electrons overall, yet 14 valence electrons are present in this configuration. Thus, this is not the proper Lewis structure.

2. While both elements' octets are full in the second form, the total valence electron is incorrect. Total valence electrons should be =7+6+1=14, with 7 coming from the 7 valence electrons of a Cl atom, 6 from the 6 valence electrons of O, and 1 from the negative charge. Yet, there are a total of 8 + 4 = 12 electrons in the structure, where 8 is for 4 lone pairs of electrons and 4 is from the double bond. Thus, it is likewise an improper Lewis structure.

3. The valence electron count in the N2 molecule, the third structure, is accurate. The N atom, however, has not yet reached octet. There are 6 electrons in each N. The two N atoms do not thus have an octet arrangement. Thus, it is not a valid Lewis structure.

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The equilibrium partial pressure of CH4(g) is 0.417 atm.

For the following reaction, Kp = 0.262 at 1000°C: C(s) + 2H2(g) ⇌ CH4(g) At equilibrium, the partial pressure of H2 is 1.26 atm.

The equilibrium constant (Kp) is defined as the ratio of the partial pressures of products to the partial pressures of reactants with each concentration term raised to a power equivalent to its coefficient in the balanced chemical equation.

At equilibrium, the partial pressure of H2 is 1.26 atm. CH4 partial pressure can be calculated by applying the equilibrium constant to this value. Here are the steps for calculating the equilibrium partial pressure of CH4(g): Write the equilibrium equation and the corresponding Kp expression.

Calculate the value of Kp.Substitute the known partial pressure of H2 into the equilibrium expression and solve for the unknown equilibrium partial pressure of CH4(g).At equilibrium, C(s) + 2H2(g) ⇌ CH4(g)The Kp expression is: Kp = PCH4/PH2²Kp = 0.262PCH4 = (Kp)(PH2²)PCH4 = (0.262)(1.26²)PCH4 = 0.417 atm

Therefore, the equilibrium partial pressure of CH4(g) is 0.417 atm.

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If you want to distinguish between the contents of two unlabeled cups, one containing Powerade White Cherry and the other containing Canada Dry Club Soda, you can use a pH indicator.

To impress your roommates with your chemistry skills, you need to select an indicator that can differentiate between the two based on their pH values. Powerade White Cherry has a pH of 2.8 while Canada Dry Club Soda has a pH of 5.2.

Looking at the table of pH indicators, there are two options that cover the pH range of both substances: Bromothymol blue and Phenolphthalein. However, Bromothymol blue has a pH range of 6.0-7.6, which is not low enough to detect the acidity of Powerade White Cherry.

Hence, choose Phenolphthalein, which has a pH range of 8.2-10.0, encompassing both 2.8 and 5.2. By using Phenolphthalein as an indicator, you can impress your roommates with your chemistry knowledge and successfully distinguish between the two cups.

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The substance tested is likely marijuana or related cannabis compounds if the Duquenois-Levine test turns purple.

In the event that the Duquenois-Levine arrangement becomes purple when added to an example, it recommends the presence of maryjane or other marijuana related substances.

The Duquenois-Levine test is a colorimetric test used to recognize the presence of weed in an example. It includes blending the example in with a progression of reagents, including Duquenois reagent and chloroform. Assuming the subsequent chloroform layer becomes purple, it proposes the presence of cannabinoids, which are the dynamic mixtures tracked down in cannabis.

It is essential to take note of that the Duquenois-Levine test isn't conclusive and can't be utilized to affirm the presence of maryjane all alone. All things considered, it is in many cases utilized as a fundamental screening test and might be circled back to other corroborative tests to give a more exact distinguishing proof.

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Kinetic molecular theory states that there is no attractive and repulsive force between the gas molecules. So option (3) is false.

According to the kinetic molecular theory the gases are composed of a large number of particles that behave like hard, spherical objects in a state of constant which is in random motion. This theory states that the energy that an object has because of its motion. The Kinetic Molecular Theory can be explained as the forces between molecules and the energy that they possess. This is explained as a theoretical model which describes the molecular composition of the gas in terms of a large number of submicroscopic particles that includes atoms and molecules. This states that the gas pressure arises due to particles colliding with each other and the walls of the container.

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The complete question is,

Which of the following statements about the kinetic-molecular theory of gases is false?

1. the average kinetic energy of a gas molecule is independent of the temperature.

2. collisions between molecules are elastic.

3. Attractive and repulsive forces are present between gas molecule.

Being non-polar molecules, acetone and pentane interact by London dispersion forces. Option a is correct.

Both acetone and pentane are non-polar molecules and interact through London dispersion forces, which are the weakest type of intermolecular force and arise from temporary dipoles induced in the molecules.

Neither acetone nor pentane has a hydrogen atom bonded to a highly electronegative atom, which is necessary for hydrogen bonding. Ion-induced dipole interactions arise between an ion and a non-polar molecule, but neither acetone nor pentane is an ion. Dipole-dipole interactions occur between polar molecules, but acetone is a polar molecule and pentane is non-polar, so they cannot interact through this type of force. Hence option a is correct.

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--The complete question is, How acetone and pentane interact.
Choose one or more: a. london dispersion b. hydrogen bonding c. ion-induced dipole d. dipole-dipole--

There are 1.69 x 10²² molecules of NaClO4 in 4.446 g of NaClO4.

Avogadro's number (6.022 x 10²³) is the basis of calculations that convert grams to atoms or molecules.

The molar mass of NaClO4 is 22.99 + 35.45 + 4(16.00) = 146.99 g/mol, which is found by adding the atomic masses of each component. This is then converted to moles by dividing the mass of the sample by the molar mass.

The number of molecules can be found by multiplying the number of moles by Avogadro's number, which gives the number of molecules. The following is the calculation:

mass of NaClO4 = 4.446 g
molar mass of NaClO4 = 146.99 g/mol

moles of NaClO4 = mass / molar mass = 4.446 g / 146.99 g/mol = 0.03022 mol

Number of molecules = Avogadro's number × moles = (6.022 x 10²³) x 0.03022 = 1.69 x 10²² molecules

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Answer:

  12.5 g/cm³

Explanation:

You want the density of a rock that has a mass of 125 g and displaces 10 mL of water in a graduated cylinder.

The balance shows a mass that is the sum of the readings on the different beams:

  20 +100 + 5 = 125

We presume the balance is measuring grams.

The graduated cylinder shows an increase in volume from 20 mL to 30 mL when the rock is added to the water. This means the rock has a displacement of ...

  30 mL -20 mL = 10 mL = 10 cm³

The density is found using the given formula:

  density = mass/volume

  density = (125 g)/(10 cm³) = 12.5 g/cm³

The density of the rock is 12.5 g/cm³.

Photochemical oxidants are examples of secondary pollutants.

Photochemical oxidants are secondary pollutants as they are formed in the atmosphere due to the combination of primary pollutants, such as nitrogen oxides and volatile organic compounds, with sunlight. These oxidants can cause smog, respiratory problems, and other environmental issues.

The other options mentioned in the question are: Aerosols, volatile organic compounds, combustion gases, and dust from soil erosion are examples of primary pollutants.Aerosols are solid or liquid particles that are suspended in the air. They can come from natural sources like dust or volcanic ash, or human-made sources like industrial emissions.

Volatile organic compounds (VOCs) are organic chemicals that easily evaporate into the air. They are emitted by many sources such as motor vehicles, industrial processes, and household products.Combustion gases are produced by the burning of fossil fuels or biomass. They can contribute to smog and other environmental problems.Dust from soil erosion is also a primary pollutant, which can cause respiratory problems and contribute to air pollution.

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The initial concentration of 'A' was approximately 1.371 M.

To determine the initial concentration of 'A' given the reaction rate constant, time, and the remaining amount of 'A', you can use the integrated rate law equation for a first-order reaction:

[A]t = [A]₀ * e^(-kt)

where:
[A]t = concentration of 'A' at time t (0.048 M)
[A]₀ = initial concentration of 'A'
k = reaction rate constant (0.012 M⁻¹ s⁻¹)
t = time in seconds (27 minutes = 27 * 60 = 1620 seconds)

Now, let's solve for [A]₀:

0.048 M = [A]₀ * e^(-0.012 M⁻¹ s⁻¹ * 1620 s)

To find [A]₀, divide both sides by e^(-0.012 * 1620):

[A]₀ = 0.048 M / e^(-0.012 * 1620)

Now, calculate the value:

[A]₀ ≈ 0.048 M / e^(-19.44)

[A]₀ ≈ 0.048 M / 0.000035

[A]₀ ≈ 1.371 M

So, the initial concentration of A was approximately 1.371 M.

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The pH of the solution is 11.13.

First, let's write the balanced chemical equation for the reaction:

NH₂NH₂ + H₂O ↔ NH₂NH₃⁺ + OH⁻

The Kb expression for this reaction is,

Kb = [NH₂NH₃⁺][OH⁻] / [NH₂NH₂]

Since we're given the concentration of NH₂NH₂ and NH₂NH₃⁺, we can use the Kb expression to find [OH⁻]:

Kb = [NH₂NH₃⁺][OH⁻] / [NH₂NH₂]

1.7 × 10^-6 = (0.387-x)x / (0.258+x)

where x is the concentration of  ion in mol/L.

Solving for x, we get:

x = 7.43 × 10^-4 M

Therefore, the concentration of OH⁻ ion in the solution is 7.43 × 10^-4 M. To find the pH of the solution, we can use the equation:

pH = 14 - pOH = 14 - (-log[OH⁻]) = 11.13.

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Phenyl bromide is the limiting reagent in the Grignard reaction, as it produces the smallest number of moles of the Grignard reagent compared to magnesium and carbon dioxide.

The balanced equation for the Grignard reaction between phenyl bromide and carbon dioxide is:

C₆H₅Br + Mg + CO₂ → C₆H₅COOMgBr

To determine the limiting reagent in the reaction, we need to calculate the number of moles of each reactant and compare them to the stoichiometric coefficients in the balanced equation. The limiting reagent is the reactant that is completely consumed in the reaction and limits the amount of product that can be formed.

The molar mass of phenyl bromide is 157.01 g/mol, and the mass used is 1.4555 g, so the number of moles of phenyl bromide is:

1.4555 g / 157.01 g/mol = 0.009271 mol

The molar mass of magnesium is 24.31 g/mol, and the mass used is 0.5734 g, so the number of moles of magnesium is:

0.5734 g / 24.31 g/mol = 0.0236 mol

The molar mass of carbon dioxide is 44.01 g/mol, and the mass used is 10.0 g, so the number of moles of carbon dioxide is:

10.0 g / 44.01 g/mol = 0.227 mol

Finally, the molarity of the HCl solution is 6.0 mol/L, and the volume used is 30.2 mL, or 0.0302 L, so the number of moles of HCl is:

6.0 mol/L x 0.0302 L = 0.1812 mol

According to the balanced equation, one mole of phenyl bromide reacts with one mole of magnesium and one mole of carbon dioxide to produce one mole of the Grignard reagent. Therefore, the limiting reagent is the reactant that produces the smallest number of moles of the Grignard reagent.

Using the above calculations, we find that the number of moles of the Grignard reagent that can be formed from each reactant is:

Since the smallest number of moles is produced from phenyl bromide, it is the limiting reagent in the reaction.

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the wavelength of this gamma ray is approximately 3.50 x [tex]10^-12[/tex] meters, which is in the range of typical gamma ray wavelengths.

The relationship between the frequency (f) and the wavelength (λ) of a wave is given by the formula:

c = fλ

where c is the speed of light in vacuum, which is approximately 3.00 x [tex]10^8[/tex] m/s.

To find the wavelength of a gamma ray with a frequency of [tex]8.56 x 10^19[/tex]Hz, we can use this formula and solve for λ:

c = fλ

λ = c / f

Substituting the given values:

λ = (3.00 x [tex]10^8[/tex] m/s) / (8.56 x  Hz)

λ ≈ 3.50 x[tex]10^-12\\[/tex] m

Frequency is a measure of how many cycles or waves of a periodic signal occur per unit of time. It is usually measured in Hertz (Hz), which represents one cycle per second. For example, a sound wave with a frequency of 440 Hz corresponds to the musical note A above middle C.

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the Clausius equation relates the change in entropy of a system to the heat flow and temperature at which the heat is transferred. This physical relationship reflects the fundamental principle that the entropy of a system tends to increase over time, and that heat flows spontaneously from hotter to cooler objects in order to achieve this increase in entropy.

The Clausius equation relates the change in entropy of a system to the heat flow and temperature at which the heat is transferred. It is given by:

ΔS = Qrev/T

where ΔS is the change in entropy of the system, Qrev is the amount of heat transferred reversibly between the system and its surroundings, and T is the temperature at which the heat is transferred.

To understand the physical basis of this equation, we need to consider the concept of entropy. Entropy is a measure of the disorder or randomness in a system. As a system evolves, it tends to move towards a state of maximum entropy, where its energy is spread out uniformly and there is no gradient or potential for further energy transfer. The second law of thermodynamics states that the entropy of an isolated system always increases over time, which implies that heat always flows spontaneously from hotter to cooler objects.

The Clausius equation relates this concept of entropy to the transfer of heat between a system and its surroundings. It tells us that the change in entropy of a system is proportional to the amount of heat transferred reversibly between the system and its surroundings, and inversely proportional to the temperature at which the heat is transferred. The term "reversible" refers to a process that can be reversed with infinitesimal changes to external conditions, so that the system and its surroundings return to their original states.

The physical relationship between the quantities in the Clausius equation can be understood as follows. The change in entropy of a system is related to the amount of heat transferred reversibly between the system and its surroundings, because heat flow is a key factor in determining the degree of disorder or randomness in a system. As heat flows from a hotter object to a cooler object, it tends to spread out and become more evenly distributed, which increases the entropy of the system. The temperature at which the heat is transferred is also important, because the higher the temperature, the greater the potential for heat to flow and increase the entropy of the system.

In summary, the Clausius equation relates the change in entropy of a system to the heat flow and temperature at which the heat is transferred. This physical relationship reflects the fundamental principle that the entropy of a system tends to increase over time, and that heat flows spontaneously from hotter to cooler objects in order to achieve this increase in entropy.
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The classification of an acid or base as weak or strong is primarily determined by the extent of dissociation in water.

The characterization of a corrosive or a base as frail or solid not entirely set in stone by the degree of separation of the broke down corrosive or base, which is otherwise called the ionization steady. A solid corrosive or base totally separates in water, creating a high centralization of hydrogen or hydroxide particles, separately.

Conversely, a powerless corrosive or base just to some extent separates, bringing about a lower centralization of particles. The solvency of the corrosive or base and its fixation likewise assume a part in deciding its solidarity, however they are not the essential variables. The grouping of a corrosive or base is connected with its solidarity, yet not by any means the only element decides its solidarity.

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The correct answer is 8. To determine the number of hydrogen atoms (H) in (NH4)2CO3, we need to count the number of H atoms in each of the constituent ions and then multiply by the number of ions present in the formula.

The (NH4)2CO3 formula contains two ammonium ions (NH4+) and one carbonate ion (CO32-). Each ammonium ion contains four hydrogen atoms, while the carbonate ion contains no hydrogen atoms.

Therefore, the total number of hydrogen atoms in (NH4)2CO3 is:

2 ammonium ions x 4 hydrogen atoms per ammonium ion = 8 hydrogen atoms

Thus, the correct answer is 8.

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The main causes of the Grevy's zebra population decrease are habitat degradation, competition for resources with domestic livestock, and hunting for their skins and meat.

The main factor contributing to the decrease of Grevy's zebras in Ethiopia is hunting. Although their striking skins are the main reason they are hunted, they are also rarely slain for food and, in some areas, for medicinal purposes.

Zebras from Grevy's are in peril. Grevy's zebras have experienced one of the greatest range reductions of any African animal, and are now restricted to northern Kenya and southern and eastern Ethiopia. They are no longer residing in Somalia, Eritrea, Djibouti, and it's possible that they've left Sudan as well.

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When silver nitrate and sodium chloride are combined with water, silver chloride will solidify and precipitate out of solution. In this instance, silver chloride is the precipitate.

Precipitation includes the following: rain, hail, sleet, and snow. Rain forms when water vapour in clouds condenses on dust particles, which eventually grow too big to stay in the cloud and fall to the ground, where they collect more water and enlarge further.

The chemical reaction between potassium chloride and silver nitrate, in which solid silver chloride precipitated out, is among the greatest examples of precipitation reactions. This precipitation reaction resulted in the formation of an insoluble salt.

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2.56 x 10²² propane molecules must be burned with 6.82 grams of oxygen.

The following is the balanced equation for propane combustion:

[tex]C3H8 + O2 = 3CO2 + 4H2O[/tex]

Hence, we require 5 oxygen molecules for every molecule of propane.

We must multiply the quantity of propane molecules by the ratio of oxygen molecules to propane molecules in order to determine how many oxygen molecules are needed to burn 2.56 x 1022 propane molecules.

[tex]O2[/tex] to [tex]C3H8[/tex] Ratio: 5:1

The necessary number of O2 molecules is (5/1) times 2.56, which equals 1.28 x 10²³.

So, using the molar mass of oxygen, we can convert the quantity of oxygen molecules to grams.

1 mole of [tex]O2[/tex] = 32 g

1.28 x 10²³ molecules of O2 = (1.28 x 10²³/ 6.022 x 10²³) moles of O2

Mass of [tex]O2[/tex] = (1.28 x 10²³/ 6.022 x 10²³) x 32 g.

Mass of [tex]O2[/tex] = 6.82 grams.

Hence, 6.82 grams of [tex]O2[/tex] are required to burn 2.56 x 10²² propane molecules.

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According to the BOD values given, the rate constant (k) is approximately 0.0291 per day at 20°C.

BOD or biochemical oxygen demand is the amount of dissolved oxygen absorbed by aerobic bacteria growing on the organic material present in a water sample at a certain temperature during a specific period measured analytically.

To calculate the rate constant (k), we can use the following formula:

k = ln(BOD1/BOD2)/t

Where,

BOD1 = Initial BOD concentration

BOD2 = BOD concentration after time t

t = time elapsed in days

Given that,

BOD concentration at the end of 7 days (BOD2) = 60.0 ml/l

Ultimate BOD concentration (BOD1) = 85.0 ml/l.

The time elapsed (t) = 7 days.

Therefore,

k = (ln(85.0/60.0))/7

k = 0.0291 per day

Thus, the rate constant (k) is approximately 0.0291 per day at 20°C.

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Answer:

where is the photo

Explanation:

where is it???

The concentration of the conjugate base at the equivalence point after the initial neutralization is 0.152 M. Then the answer is 0.152 M.

When titrating an acid with a base, we can determine the concentration of the conjugate base at the equivalence point using the equation MaVa = MbVb. So in order to reach the equivalence point in their titration, Sonni needed to add 19.42 ml of KOH to 20.00 ml of 0.309 M HF.

What is the concentration of the conjugate base at the equivalence point after the initial neutralization?SolutionWe can start by writing the balanced chemical equation for the reaction between KOH and HF:HF + KOH → KF + H2OSince the equation is balanced,

we can say that 1 mole of HF reacts with 1 mole of KOH to produce 1 mole of KF and 1 mole of H2O. Therefore, the moles of KOH added to the solution is equal to the moles of HF present initially:

moles of KOH = Molarity × Volume in liters

= 0.309 M × (19.42 / 1000) L

= 0.006007 Mmoles of HF

= Molarity × Volume in liters

= 0.309 M × (20.00 / 1000) L

= 0.00618 MSince the moles of KOH added is slightly less than the moles of HF present initially, the solution is still acidic, and there is still some HF remaining after the initial neutralization. At the equivalence point, all of the HF has reacted with KOH,

and the solution contains only KF and water. So, we can use the balanced chemical equation to calculate the number of moles of KF produced when all of the HF has reacted with KOH.

Number of moles of KF = 0.006007 mol

HF + KOH → KF + H2O1 mole HF produces 1 mole KF;

therefore, 0.006007 moles HF will produce 0.006007 moles of KF. The volume of the solution at the equivalence point is 19.42 ml + 20.00 ml = 39.42 ml = 0.03942 L.

Therefore, the concentration of KF at the equivalence point is:Concentration of KF = (0.006007 mol) / (0.03942 L)= 0.152 MFinally, we know that KF is the conjugate base of HF,  

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We need 1.08 mL of NaOH solution to reach a pH of 7.10.

To solve this problem, we need to use the balanced chemical equation for the neutralization reaction between phosphoric acid (H₃PO₄) and potassium hydroxide (KOH); H₃PO₄ + 3KOH → K₃PO₄ + 3H₂O

From the equation, we can see that one mole of H₃PO₄ reacts with three moles of KOH. Therefore, the number of moles of KOH required to neutralize 0.149 moles of H₃PO₄ is;

n(KOH) = 3 × n(H₃PO₄) = 3 × 0.149 mol = 0.447 mol

Next, we need to calculate the volume of 1.250 M KOH solution that contains 0.447 mol of KOH;

V(KOH) = n(KOH) / C(KOH) = 0.447 mol / 1.250 mol/L

= 0.358 L = 358 mL

So, 358 mL of 1.250 M KOH solution is required to neutralize the 0.149 moles of H₃PO₄.

Now, to reach a pH of 7.10, we need to add a strong base such as NaOH to the solution until the pH reaches the desired value. Since NaOH is a strong base, it will react completely with the remaining H₃PO₄ to form water and sodium phosphate (Na₃PO₄)

H₃PO₄ + 3NaOH → Na₃PO₄ + 3H₂O

To calculate the volume of NaOH solution required to reach a pH of 7.10, we need to know the initial pH of the solution. Assuming that the solution is initially acidic, we can use the Henderson-Hasselbalch equation to calculate the initial pH;

pH = pKa + log([A]/[HA])

where pKa is the dissociation constant of H₃PO₄, [A] is the concentration of the conjugate base (H₂PO₄⁻), and [HA] is the concentration of the acid (H₃PO₄).

The pKa values for phosphoric acid are;

pKa₁ = 2.148

pKa₂ = 7.198

pKa₃ = 12.319

Since we are assuming that the solution is initially acidic, we can use the first dissociation constant (pKa1 = 2.148) to calculate the concentration of H₂PO₄⁻;

[H₂PO₄⁻] = [A] = K × [HA] / (K + [HA])

where K is the equilibrium constant for the dissociation of H₃PO₄:

K = [H⁺][H₂PO₄⁻] / [H₃PO₄]

At a pH of 7.10, [H⁺] = [tex]10^{-7.10}[/tex] = 7.94 × 10⁻⁸ M. Substituting this value into the equation for K and solving for [H₂PO₄⁻], we get:

K = 7.94 × 10⁻⁸ × [H₂PO₄⁻] / 0.149 M

[H₂PO₄⁻] = (K × 0.149 M) / 7.94 × 10⁻⁸

[H₂PO₄⁻] = 2.81 × 10⁻⁵ M

Now we can use the Henderson-Hasselbalch equation to calculate the initial pH:

pH = pKa₁ + log([A]/[HA])

= 2.148 + log(2.81 × 10⁻⁵ / 0.149)

= 1.08

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--The given question is incomplete, the complete question is

"A solution made with 0.149 moles of phosporic acid (H₃PO₄) dissolved in 159mL of solution was titrated with 1.250 M KOH . How many mL of NaOH solution are necessary to reach a pH of 7.10?"--

Answer:

Answer and Explanation: Vapor pressure has an inverse relationship with intermolecular forces. This means that the stronger the intermolecular forces are, the lower the vapor pressure is.

Answer:

Explanation:

The intermolecular forces in carbon dioxide are weak, so its vapor pressure is relatively high.

A higher pH indicates a higher concentration of hydroxide in an aqueous solution containing a weak base. The correct answer is (A).

At much higher concentrations, acid A can be weaker than acid B, which is strong. As a result, A's pH is lower because it can still dissociate to produce more H+ in the solution.

pH is a proportion of how acidic/fundamental water is. The range is 0 to 14, with 7 representing neutrality. pH values below 7 indicate acidity, while pH values above 7 indicate a base. pH is a proportion of the overall measure of free hydrogen and hydroxyl particles in the water.

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Q- when looking at an aqueous solution of a weak acid, a lower ph corresponds to: select the correct answer below:

A. a higher concentration of hydronium

B. a lower concentration of hydronium

C. a higher concentration of hydroxide

D. a more dilute solution

According to the Beer lamberts law the absorbance is directly proportional to the concentration of the sample.

Beer-lambert Law states that when the extinction coefficient and the path length are constant, the absorbance is proportional to the concentration of the sample. According to this law the absorbance is directly proportional to the length of the light path.  It is equals to the inner width of the cuvette. It  is evident that the path length affects absorbance. We know that with a longer optical path length, the light has to travel through more solution and can hit more molecules or atoms and be absorbed more of the solution. The absorbance is directly proportional to the concentration of the given sample.

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The  complete question is,

Does stopper affect absorbance?