Please circle the process which does not involve irreversibility: (A) The conversion of mechanical work to heat by friction. (B) Conversion of electrical energy to thermal energy through a resistor heater. (C) Mixing of O2 and N2 for the production of air. (D) The theoretical conversion from electricity to mechanical work.

The enthalpy change (ΔH°) for each reaction can be calculated using the given enthalpy of formation (ΔH°f) values. ΔH°1 = (4ΔH°f(NO) + 6ΔH°f(H2O)) - (4ΔH°f(NH3) + 5ΔH°f(O2)). ΔH°2 = (2ΔH°f(NO2)) - (2ΔH°f(NO) + ΔH°f(O2)). ΔH°3 = (2ΔH°f(HNO3) + ΔH°f(NO)) - (3ΔH°f(NO2) + ΔH°f(H2O)).

In order to determine the enthalpy change (ΔH°) for each reaction, we need to use the given enthalpy of formation (ΔH°f) values. The enthalpy change for each reaction can be calculated by subtracting the sum of the enthalpy of formation of the reactants from the sum of the enthalpy of formation of the products. Using this method, we can calculate the enthalpy change for each of the preceding reactions as follows:

ΔH°1 = (4ΔH°f(NO) + 6ΔH°f(H2O)) - (4ΔH°f(NH3) + 5ΔH°f(O2))

ΔH°2 = (2ΔH°f(NO2)) - (2ΔH°f(NO) + ΔH°f(O2))

ΔH°3 = (2ΔH°f(HNO3) + ΔH°f(NO)) - (3ΔH°f(NO2) + ΔH°f(H2O))

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The ΔH° for each reaction in the Ostwald process is calculated with a specific formula, and the overall ΔH° is found by summing the individual values. The final reaction is 4NH3(g) + 5O2(g) → 4HNO3(aq) with ΔH° = -1192 kJ.

In The Ostwald process, the ΔH° for each reaction is calculated with the formula: ΔH° = ΣΔH°f(products) - ΣΔH°f(reactants). So, for the first reaction, 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g), we calculate ΔH°1 = [4(90) + 6(-242)] - [4(-46) + 5(0)] = -906 kJ. The second reaction, 2NO(g) + O2(g) → 2NO2(g), gives ΔH°2 = [2(34)] - [2(90) + 0] = -112 kJ. Lastly, for 3NO2(g) + H2O(l) → 2HNO3(aq) + NO(g), ΔH°3 = [2(-207) + 90] - [3(34) + -286] = -174 kJ.
Now, adding all three reactions, we get the overall reaction: 4NH3(g) + 5O2(g) → 4HNO3(aq), with the overall ΔH° = -1192 kJ.

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Answer: 97.2°c

Explanation:Given

Heat added Q=102.5KJ

Mass m=300g

Iniatial temperature t1=15.5°c

Final temperature t2=?

Specific heat capacity c=4.184

Recall Q=mc(t2-t1)

102500=300*4.184(t2-15.5)

t2-15.5=81.66

T2=97.2°c

Answer:

97.16°C

Explanation:

Step 1:

Data obtained from the question. This includes:

Heat (Q) = 102.5 kJ = 102.5 x 1000 = 102500J

Mass (M) = 300 g

Initial temperature (T1) = 15.5°C

Specific heat capacity (C) = 4.184 J/g°C

Final temperature (T2) =?

Change in temperatures (ΔT) = T2 - T1 = T2 - 15.5

Step 2:

Determination of the final temperature.

Applying the following equation:

Q = MCΔT

We can easily calculate the value of the final temperature as follow:

Q = MCΔT

Q = MC(T2 - T1)

102500 = 300 x 4.184 (T2 - 15.5)

102500 = 1255.2 x (T2 - 15.5)

Divide both side by 1255.2

(T2 - 15.5) = 102500/1255.2

T2 - 15.5 = 81.66

Collect like terms

T2 = 81.66 + 15.5

T2 = 97.16°C

Therefore, the final temperature of the water is 97.16°C

Answer:

The strength of a bond depends on the amount of overlap between the two orbitals of the bonding atoms

Orbitals bond in the directions in which they protrude or point to obtain maximum overlap

Explanation:

The valence bond theory was proposed by Linus Pauling. Compounds are firmed by overlap of atomic orbitals to attain a favourable overlap integral. The better the overlap integral (extent of overlap) the better or stringer the covalent bond.

Orbitals overlap in directions which ensure a maximum overlap of atomic orbitals in the covalent bond.

Answer:

THE STRENGTH OF THE BOND DEPENDS ON THE AMOUNT OF OVERLAP BETWEEN THE TWO ORBITALS OF THE BONDING ATOMS

ORBITALS BOND IN THE DIRECTION OR POINT IN WHICH THEY PROTRUDE OR POINT TO OBTAIN MAXIMUM OVERLAP.

Explanation:

Valence bond theory describes the covalent bond as the overlap of half-filled atomic orbital yields a pair of electrons shared between the two bonded atoms. Overlapping of orbitals occurs when a portion of one orbital and the other occur in the same region of space. The strength of a bond is determined by the amount of overlap between the two orbitals of the bonding atoms. In other words, orbitals that overlap more and in the right orientation of maximum overlapping form stronger bonds that those with less overlap and right orientation for maximum overlap. The bonding occurs at a varying distance in different atoms from which it obtains its stable energy caused by the increase in the attraction of nuclei for the electrons.

Orbitals also bond in the direction to obtain maximum overlap as orientation of the atoms also affect overlap. The greater overlap occurs when atoms are oriented on a direct line mostly end to end or side by side between the two nuclei depending on the type of bond formed. A sigma bond is formed when atoms overlap end to end in which a straight line exists between the two atoms that is the internuclear axis indicating the concentrated energy  density in that region. Pi bond exits in when overlap occurs in the side -to -side orientation and the energy density is concentrated opposite the internuclear axis.

The molar concentration of sodium ions in a 0.650M Na₃PO₄ solution is equal to 1.95M.

The concentration of the solution can be determined when we have the molecular formula and its molecular weight. We can easily determine the molar concentration of a substance in a solution.

The concentration of the solution calculated as the number of moles of a solute in a liter of a solution is called molarity or molar concentration.

The Molar concentration of the solution is determined in the following way.

Molarity (M) = Moles (n) of solute/Volume of the Solution ( in L)

Given, the molar concentration of the Na₃PO₄ solution = 0.650 M

The dissociation of Na₃PO₄ into ions can be represented as:

Na₃PO₄   →   3 Na⁺   +   PO₄³⁻

From the above equation, we can say that one mole of the  Na₃PO₄  gives 3 moles of sodium ions.

The molar concentration of sodium ions in  Na₃PO₄ solution = 3× 0.650

The molar concentration of Na⁺ions = 1.95M

Therefore, the molar concentration of Na⁺ions in Na₃PO₄ solution is 1.95M.

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Final answer:

To calculate the cell potential for the given galvanic cell reaction, you can use the Nernst equation and the standard cell potential. Plug in the concentrations of Fe3+ and Au3+ and calculate the cell potential using the Nernst equation at 25°C.

Explanation:

The cell potential for the galvanic cell can be calculated using the Nernst equation, which is given by: Ecell = E°cell - (0.0592/n) * log(Q)

where E°cell is the standard cell potential, n is the number of electrons transferred in the reaction, and Q is the reaction quotient.

In this case, the reaction is: Fe(s) + Au3+(aq) -> Fe3+(aq) + Au(s)

The standard cell potential can be found in Appendix L. Plugging in the concentrations of Fe3+ and Au3+, as well as the standard cell potential, into the Nernst equation will give the cell potential at 25°C.

The cell potential for the given galvanic cell at 25°C is approximately 1.589 V.

This calculation involves determining standard reduction potentials, using the Nernst equation, and considering the reaction quotient.

To calculate the cell potential for the galvanic cell with the reaction:
Fe(s) + Au³⁺ (aq) → Fe³⁺ (aq) + Au (s) at 25°C with [Fe³⁺] = 0.00150 M and [Au³⁺] = 0.797 M, we can follow these steps:

Determine the standard reduction potentials:

Calculate the standard cell potential (E°cell) using the formula:

E°cell = E°cathode - E°anode

Use the Nernst equation to find the cell potential under non-standard conditions:

Plugging in the values:

Therefore, the cell potential for the given galvanic cell at 25°C is approximately 1.589 V.

Answer:

986.9 °C

Explanation:

To find the temperature we can use the Arrhenius equation:

[tex] k = Ae^{(-E_{a}/RT)} [/tex]   (1)

Where:

k: is the reaction rate coefficient

A: is the pre-exponential factor

Ea: is the activation energy

R: is the gas constant

T: is the absolute temperature

With the values given:

T = 590 °C = 863 K; Ea = 117 kJ/mol; k = 0.00289 s⁻¹,

we can find the pre-exponential factor, A:

[tex]A = \frac{k}{e^{(-E_{a}/RT)}} = \frac{0.00289 s^{-1}}{e^{(-117 \cdot 10^{3} J*mol^{-1}/(8.314 J*K^{-1}*mol^{-1}*863 K))}} = 3.49 \cdot 10^{4} s^{-1}[/tex]

Now, we can find the temperature by solving equation (1) for T:

[tex] ln(\frac{k}{A}) = -\frac{E_{a}}{RT} [/tex]

[tex] T = -\frac{E_{a}}{R*ln(\frac{k}{A})} = -\frac{117 \cdot 10^{3} J*mol^{-1}}{8.314 J*K^{-1}*mol^{-1}*ln(\frac{0.492 s^{-1}}{3.49 \cdot 10^{4} s^{-1}})} = 1259.9 K = 986.9 ^{\circ} C [/tex]

Therefore, at 986.9 °C, the rate constant will be 0.492 s⁻¹.

I hope it helps you!  

Answer:

The temperature is 1259.4 K (986.4°C)

Explanation:

Step 1: Data given

The activation energy Ea, = 117 kJ/mol

the rate constant for the reaction is 0.00289 s −1 at 590 °C

The new rate constant = 0.492 s −1

Step 2: Calculate the temperature

ln(kX / k 590°C)  =  Ea/R * (1/T1 - 1/T2)

⇒with kX is the rate constant at the new temperature = 0.492 /s

⇒with k 590 °C = the rate constant at 590 °C = 0.00289 /s

⇒with Ea = the activation energy = 117000 J/mol

⇒with R = the gas constant = 8.314 J/mol*K

⇒with T1 = 590 °C = 863 K

⇒ with T2 = the new temperature

ln (0.492 / 0.00289) = 117000/8.314 *(1/863 - 1/T2)

5.137 =14072.6 * (1/863 - 1/T2)

3.65*10^-4 = (1/863 - 1/T2)

3.65*10^-4 = 0.001159 - 1/T2

0,000794‬ = 1/T2

T2 = 1259.4 K

The temperature is 1259.4 K or 986.4 °C

Answer:

c. ΔH° is positive and ΔS° is positive.

Explanation:

Hello,

In this case, as the Gibbs free energy for a reaction is defined in terms of the change in the enthalpy and entropy as shown below:

[tex]\Delta G=\Delta H-T\Delta S[/tex]

Thus, as the reaction becomes spontaneous (ΔG°<0) at temperatures above 1100K (high temperatures), it necessary that c. ΔH° is positive and ΔS° is positive as the entropy will drive the spontaneousness as it becomes smaller than TΔS°.

Best regards.

Final answer:

The reaction C(s) + CO2(g) → 2CO(g) being only spontaneous at high temperatures above 1100K indicates that the reaction has a positive ΔH° and a positive ΔS°, corresponding to option c.

Explanation:

The reaction C(s) + CO2(g) → 2CO(g) is spontaneous only at temperatures above 1100 K. This information allows us to infer the signs of ΔH° (enthalpy change) and ΔS° (entropy change). According to Gibbs free energy equation, ΔG = ΔH - TΔS, a reaction is spontaneous when ΔG is negative. Given that the reaction is only spontaneous at high temperatures, this suggests that ΔH° is positive (endothermic reaction) and ΔS° is positive (increase in disorder). At lower temperatures, the TΔS term is not sufficient to overcome the positive ΔH°, making ΔG positive and the reaction non-spontaneous. Hence, the correct conclusion is that the reaction is spontaneous at high temperatures because of a positive ΔH° and a positive ΔS°, indicating option c.

Answer: 1) C; 2)D; 3)B; 4)B; 5) A

Explanation:Interpreting the following Arterial Blood gases, we have

1. pH 7.33 PaCO2 60 HCO3  34----Respiratory acidosis with partial compensation----C

2. pH 7.48 PaCO2 42 HCO3 30------. Metabolic alkalosis without compensation----D

3. pH 7.38 PaCO2 38 HCO3 24 ----- Normal---B

4. pH 7.21 PaCO2 60 HCO3 24------ Respiratory acidosis without compensation-----B

5. pH 7.48 PaCO2 28 HCO3 20 ----Respiratory alkalosis with partial compensation

The Arterial blood gas interpretation  from analysis shows  the pH and the partial pressures of oxygen and carbon dioxide in the arterial blood of an individual which can detect how well the lungs are functioning thereby making a physician make a diagnosis, estimate  the severity of a condition and profer treatment.

The balanced thermochemical equation for the reaction where Hydrogen gas reacts with Oxygen gas to form Water with the release of 242 kJ energy is 2H2(g) + O2(g) → 2H2O(g) ΔH = -242 kJ. This indicates an exothermic reaction.

The balanced thermochemical equation of the reaction where Hydrogen gas (H2) reacts with Oxygen gas (O2) to form Water (H2O) and 242 kJ (kilojoules) energy is released per mole of H2, can be formulated as follows:

2H2(g) + O2(g) → 2H2O(g) ΔH = -242 kJ

The negative sign before the energy value indicates that it's an exothermic reaction, meaning that energy is released during the reaction.

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c. All three titrations have the same pH at their first equivalence point.

Explanation:

- In the titration of a monoprotic weak acid with NaOH (i), the first equivalence point corresponds to the complete neutralization of the weak acid with NaOH. The pH at this point is determined by the salt formed, and for a monoprotic weak acid, it will be neutral (pH 7).

- In the titration of a diprotic weak acid with NaOH (ii), the first equivalence point also corresponds to the neutralization of the weak acid with NaOH. The pH at this point is determined by the salt formed, and it will also be neutral (pH 7).

- In the titration of a strong acid with NaOH (iii), the first equivalence point is when the strong acid is completely neutralized by NaOH. The resulting solution will be basic, with a pH greater than 7.

Therefore, the statement "All three titrations have the same pH at their first equivalence point" is most likely to be true.

Answer:

b. It is when a change that indicates equivalence is observed in the analyte solution.

Explanation:

The end point of a titration is the point at which the indicator undergoes the change noticeable by our senses. Ideally, the equivalence point and end point coincide; but this does not usually happen in practice, because the indicator does not always change perceptibly at the same moment in which the equivalence point is reached and also for the change of the indicator, some of the reagent used in the evaluation is usually necessary .

The difference between the end point and the equivalence point of a valuation is called the valuation error or end point error.

At this point the pH changes the color of the indicator. nvhdurn

Final answer:

The end point of a titration is the moment observed (option b) when a change, due to an indicator or sensor, suggests that stoichiometric equivalence has been reached. It is an experimental determination and serves as the best estimate of the theoretical equivalence point.

Explanation:

The end point of a titration is not a synonym for the equivalence point. Rather, it represents the moment during a titration when a change indicating equivalence is observed in the analyte solution (option b). This point is typically detected through a change in color due to an indicator or through a change detected by a sensor. It is important to note that the end point is an experimental value, our best estimate of the equivalence point, and that any difference between the end point and the theoretical equivalence point is a source of determinate error.

In an acid-base titration, the end point is often observed when a pH indicator changes color, signifying that a stoichiometric amount of titrant has been added to the analyte. In redox and complexation titrations, it can be detected by changes in the solution conditions that are measurable by indicators and sensors.

The statement is true as all Ionic compounds are called Electrolytes because they  dissociate(break apart) in water to form a solution that conducts electric  current.

Explanation:

An ionic compound also called an electrolyte. Ionic compounds have capability to get dissociate into water to give ions(cation and anion)  which conduct electric current. This process is called conductivity.

Some insoluble compounds that are not dissolved in water still they form ions which conduct electricity.

The cations and anions released are responsible for carrying current.

Strong acids and strong bases are the strong electrolytes as they dissociate to give more ions as NaOH, HCl.

The cations move to the cathode and anions towards the anode. Cation and anion movement in the solution is electric current.

Ionic compounds are called electrolytes because they dissociate in water to form a solution that conducts electric current.

True. Ionic compounds are called electrolytes because they dissociate (break apart) in water to form a solution that conducts electric current.

When an ionic compound like NaCl is dissolved in water, the positive sodium ions and negative chloride ions separate from each other and are surrounded by water molecules. These separated ions can move freely in the solution and carry electric charge, allowing the solution to conduct electricity.

Other examples of electrolytes include compounds like potassium chloride (KCl) and magnesium sulfate (MgSO4). These compounds also dissociate in water to produce solutions that can conduct electric current.

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Answer:

The statement which best explains the change that must happen at the molecular level is below:

Explanation:

The molecules move more slowly and their average kinetic energy decreases

Answer:

what subject is this and how can u draw the structure :)

The reaction involves reduction of the given compound using NaBH4, followed by solvolysis with ethanol and protonation with H3O. Organic molecules structures are often simplified using the skeletal structure method. The stereochemistry of compounds can be represented using wedge and dash notation.

The given reaction involves the reduction of an organic compound using NaBH4, followed by the treatment with ethanol and then H3O. When a carbonyl compound reacts with NaBH4, the borohydride group of NaBH4 (it is a weak reducing agent with H-) adds to the carbonyl carbon. This process, known as reduction, transforms the carbonyl group to an alcohol. Following reduction, the compound is undergoing solvolysis in ethanol and then protonated with H3O. Due to the restriction of the platform, displaying the structural representation of the organic product is limited.

The wedge and dash notation can be used to represent the stereochemistry of the compounds. Solid wedges represent bonds coming up out of the plane whereas dashed lines represent bonds going into the plane. These techniques assist chemists to define molecular structures in three dimensions. Skeletal structure, a common way of simplifying complex organic structures in chemistry, represents carbons as each end of a line or bend in a line.

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Answer:

Explanation:

The answer choices are:

1. Metals in the second group make bases of the form M(OH)₂

TRUE

The metals in the second group have two valence electrons, thus they can lose them to form cation with +2 oxidation state and bond with two (OH)⁻ groups, forming bases with the general formula M(OH)₂.  For instance, Mg(OH)₂ and Ca(OH)₂.

2.  Ammonium is an example of a "Nitrogen with 3 groups" base

FALSE

Ammonium is NH₃. The "nitrogen with 3 groups" base are the compounds where the three hidrogens are replaced with R-groups, where R are alkyl groups.

3. Metals in the first group make bases of the form M(OH)₂

FALSE

Since metals in first group of the periodic table have one valence electrons they make bases of the form MOH. For instance, NaOH and KOH.

4. A nitrogen with three groups and a lone pair is a base since it can accept a proton

TRUE

Since nitrogen has five valence electrons, when it bonds to three groups, it will retain a lone pair of electrons which make it a base under the Lewis concept and can accept a proton.

5. HNO₃ has N as the central atom so it is a base

FALSE

It is true that N is the central atom in HNO₃ but this compound is an acid as it releases a proton in aqueous solution.

Answer:

Explanation:

No reaction if there is no solid then the ions just stay there brah. All the ions remain in solution. We are all gonna make it!

Answer: The molarity of silver nitrate in the diluted solution is 0.015 M

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.

According to the dilution law,

[tex]M_1V_1=M_2V_2[/tex]

where,

[tex]M_1[/tex] = molarity of concentrated solution = 0.150 M

[tex]V_1[/tex] = volume of concentrated solution = 10.0 ml

[tex]M_2[/tex] = molarity of diluted solution = ?

[tex]V_2[/tex] = volume of diluted solution = 100.0 ml

[tex]0.150\times 10.0=M_2\times 100.0[/tex]

[tex]M_2=0.015M[/tex]

Thus the molarity of silver nitrate in the diluted solution is 0.015 M

Final answer:

The molarity of the diluted silver nitrate solution, prepared by diluting 10.0 mL of a 0.150 M solution to a final volume of 100.0 mL, is 0.015 M when calculated using the dilution equation.

Explanation:

The question is asking how to calculate the molarity of a diluted silver nitrate solution using the dilution equation. When 10.0 mL of a 0.150 M silver nitrate solution is diluted to 100.0 mL, the molarity of the diluted solution can be found using the equation M1V1 = M2V2, where M1 is the initial molarity, V1 is the initial volume, M2 is the final molarity, and V2 is the final volume.

Using the dilution equation:

To find M2 (the molarity of the diluted solution), rearrange the equation to M2 = (M1V1) / V2.

The molarity of the diluted silver nitrate solution would be 0.015 M (calculated as (0.150 M * 10.0 mL) / 100.0 mL).

Answer:

[tex]\large \boxed{\text{103 kPa}}[/tex]

Explanation:

We can use the Ideal Gas Law — pV = nRT

Data:

V = 66.8 L

m = 77.8 g

T = 25 °C

Calculations:

(a) Moles of N₂

[tex]\text{Moles of N}_{2} = \text{77.8 g N}_{2} \times \dfrac{\text{1 mol N}_{2}}{\text{28.01 g N}_{2}} = \text{2.778 mol N}_{2}[/tex]

(b) Convert the temperature to kelvins

T = (25 + 273.15) K = 298.15 K

(c) Calculate the pressure

[tex]\begin{array}{rcl}pV & =& nRT\\p \times \text{66.8 L} & = & \text{2.778 mol} \times \text{8.314 kPa$\cdot$ L$\cdot$K$^{-1}$mol$^{-1}\times$ 298.15 K}\\66.8p & = & \text{6886 kPa}\\p & = & \textbf{103 kPa}\end{array}\\\text{The pressure in the bag is $\large \boxed{\textbf{103 kPa}}$}[/tex]

Answer:

The correct answer is option (a) a) [AH ] > [A] ~ [H3O ] > [OH-]

Explanation:

Since AH is a weak acid, it will dissociate in lesser amount. So, less amount of A and H3O will be formed. The highest amount formed will be AH> A>  [OH-]

As it is salt of weak acid and strong base. So pH is greater than 7 and [OH-]<[H+]

When the species present in a 1.0 mol L-1 solution of a salt of weak acid AH Then The correct option is (a) [AH ] > [A] ~ [H3O ] > [OH-]

When AH is a weak acid, Then it will dissociate in a lesser amount. Then less amount of A and also H3O will be formed. Then The highest amount formed will be AH> A> [OH-]

After that As it is salt of the weak acid and strong base. Then pH is greater than 7 and also [OH-]<[H+]

Therefore, the correct is 'A'. [AH ] > [A] ~ [H3O ] > [OH-]

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Answer:

It forms an octahedral complex

Rh[NH3]5I

Explanation:

Or see structure attached below

Answer:

[ Rhl(NH₃)₅]²⁺

Explanation:

Symbol of Rhodium atom = Rh

charge of Rhodium in complex = +3

charge on Iodine in complex = -1

Charge on NH₃= 0 (neutral)

Therefore, the total charge on the complex is given as follows;

Charge on complex= +3-1 + 0

                                        = +2

Therefore, the required formula of the complex = [ Rhl(NH₃)₅]²⁺

[Note: Inside the co-ordination complex,metal is written first and followed by negative and neutral ligands respectively and charge on complex is written on the right top of the complex. therefore, the chemical formular of the given complex is given as follows; [ Rhl(NH₃)₅]²⁺

Answer:

pH = 8.9

Explanation:

To solve this problem, we need to write the overall reaction of the aqueous solution of Ca(C₇H₇COO)₂:

Ca(C₇H₇COO)₂ <----------> Ca²⁺ + 2C₇H₇COO⁻

This means that the concentration of the phenyl acetate is 2 times the concentration of the calcium phenylacetate:

[C₇H₇COO⁻] = 2 * 0.15 = 0.30 M

We have the concentration of the phenylacetate, this is a conjugate base of the phenylacetic acid, therefore, we need the Kb of the conjugate. This can be calculated using the following expression:

Kw = Kb * Ka -----> Kb = Kw/Ka

And Ka = 10^(-pKa)

Replacing the values (Assuming Kw = 1x10⁻¹⁴)

Ka = 10⁽⁻⁴°³²⁾ = 4.786x10⁻⁵

Kb = 1x10⁻¹⁴ / 4.786x10⁻⁵ = 2.089x10⁻¹⁰

Now that we have Kb, we can write the reaction of the phenylacetate in water, and an ICE chart

        C₇H₇COO⁻ + H₂O <--------> C₇H₇COOH + OH⁻    Kb = 2.089x10⁻¹⁰

i)           0.30                                        0                0

e)          0.30-x                                     x                 x

Kb = [C₇H₇COOH] [OH⁻] / [C₇H₇COO⁻]      Replacing the above values

2.089x10⁻¹⁰ = x² / 0.30 - x    

As Kb is very small, x would be a very small value too, so we can neglect 0.30 - x to 0.30 only:

2.089x10⁻¹⁰ = x² / 0.30

2.089x10⁻¹⁰ * 0.30 = x²

√6.27x10⁻¹¹ = x

x = 7.92x10⁻⁶ M

This is the concentration of the phenylacetate and OH⁻. With this value we can calculate the pOH and then, the pH:

pOH = -log[OH⁻]

pOH = -log(7.92x10⁻⁶)

pOH = 5.1

Finally the pH:

pH = 14 - pOH

pH = 14 - 5.1

The calcium phenylacetate, Ca(C7H7COO)2, at 25 ºC pH is = 8.9

Then To translate this situation, After That, we need to note the overall reaction of the aqueous resolution of Ca(C₇H₇COO)₂:

Then Ca(C₇H₇COO)₂ <----------> Ca²⁺ + 2C₇H₇COO⁻

This define that the concentration of the phenylacetate is 2 times the concentration of the calcium phenylacetate:

That is [C₇H₇COO⁻] = 2 * 0.15 is = 0.30 M

After that We have the concentration of the phenylacetate, which is a conjugate base of the phenylacetic acid, Thus, we need the Kb of the conjugate. Now, This can be calculated using the subsequent declaration:

Kw is = Kb * Ka -----> Kb is = Kw/Ka

And also Ka is = 10^(-pKa)

Then We are Replacing the values (Accepting Kw is = 1x10⁻¹⁴)

Ka is = 10⁽⁻⁴°³²⁾ = 4.786x10⁻⁵

Kb is = 1x10⁻¹⁴ / 4.786x10⁻⁵ is = 2.089x10⁻¹⁰

Now that we have Kb, then we can compose the reaction of the phenylacetate in water, and also an ICE chart

Then C₇H₇COO⁻ + H₂O <--------> C₇H₇COOH + OH⁻ Kb is = 2.089x10⁻¹⁰

i) 0.30 0 0

e) 0.30-x x x

Kb is = [C₇H₇COOH] [OH⁻] / [C₇H₇COO⁻] Then Replacing the above values

2.089x10⁻¹⁰ is = x² / 0.30 - x

When Kb is very small, x then they would be a very small value too, so we can neglect 0.30 - x to 0.30 only:

2.089x10⁻¹⁰ is = x² / 0.30

2.089x10⁻¹⁰ * 0.30 is = x²

√6.27x10⁻¹¹ is = x

x is = 7.92x10⁻⁶ M

Now This is the concentration of the phenylacetate and also OH⁻. With this value then we can calculate the pOH and also then, the pH:

pOH is = -log[OH⁻]

pOH is = -log(7.92x10⁻⁶)

pOH is = 5.1

Finally the pH is:

pH is = 14 - pOH

pH is = 14 - 5.1

Therefore pH is = 8.9

So, This is the pH of the calcium phenylacetate solution

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Answer:

The following data point should be kept when making your calibration.

1.21E-05 M

1.60E-05 M

8.09E-06 M

4.04 E-06 M

Explanation:

From the graph it is obvious that the reading for the concentration 2.02E-06 M does not fall on the straight line. So this point should not be taken to construct the calibration plot.

Find attached of the graph.    

Answer:

celulares por que tienen una fuente de energiq

Answer:

0.458 M

Explanation:

Let's consider the following reaction at equilibrium.

2 NH₃(g) ⇄ N₂(g) + 3 H₂(g)

The concentrations at equilbrium are:

[NH₃] = 0.221 mol / 10.2 L = 0.0217 M

[N₂] = 0.315 mol / 10.2 L = 0.0309 M

[H₂] = ?

We can find the concentration of H₂ at equilibrium using the equilibrium constant (K).

K = [N₂] × [H₂]³ / [NH₃]²

[H₂] = ∛(K × [NH₃]²/ [N₂])

[H₂] = ∛(6.30 × 0.0217²/ 0.0309) = 0.458 M

Answer:

The equilibrium concentration of H2 is 0.4579 M

Explanation:

Step 1: Data given

The equilibrium constant for the following reaction is 6.30 at 723K

Volume = 10.2 L

Number of moles NH3 = 0.221 moles

Number of moles N2 = 0.315 moles

Step 2: The balanced equation

2NH3 <=> N2(g) + 3H2(g)

Step 3: Calculate concentration

Concentration = moles / volume

Concentration NH3= 0.221 moles / 10.2 L

Concentration NH3 = 0.0217 M

Concentration N2 = 0.315 moles / 10.2 L

Concentration N2 = 0.0309 M

Step 4: Define Kc

Kc = [H2]³[N2] / [NH3]²

6.30 = [H2]³ * (0.0309) / (0.0217)²

[H2]³ = 0.09601 M

[H2] = 0.4579 M

The equilibrium concentration of H2 is 0.4579 M

Answer:

Explanation:

check the attached file for answers. Thanks

Answer: hundred cubic meters of carbon dioxide initially at 150◦C and 50 bar is to beisothermally compressed in a frictionless piston-and-cylinder device to a final pressure of 300 bar.Calculatei The volume of the compressed gas.ii The work done to compress the gas.iii The heat flow on compression.assuming carbon dioxide(a) Is an ideal gas.(b) Obeys the principle of corresponding states of Sec. 6.6(c) Obeys the Peng-Robinson equation of state.SolutionWe haveT1= 150◦C,P1= 50 bar,T2= 150◦C,P2= 300 bar. (1 and 2 denote the initialand final conditions in this ’snapshot’ problem, respectively - we have sometimes called themt1andt2)(a) If CO2is an idea gas, we havePV=NRT.The number of moles can be calculated from theinitial conditions:N1=P 1 V 1 RT 1 = (6 × 10 6 Pa)(100 m 3 ) (8 . 314 J/(mol K))(150 + 273 K) = 142127 mol = 142 . 1 kmol i. Since we know N 1 = N 2 , T 2 , P 2 V 2 = N 2 RT 2 P 2 = (142127 mol)(8 . 314 J/(mol K))(150 + 273 K ) 30 × 10 6 Pa = 16 . 66 m 3 ii. Since there is no shaft work, and since the gas is isothermally compressed , we only have pressure-volume work: W = - Z V 2 V 1 PdV = - Z V 2 V 1 NRT V dV = - NRT ln V 2 V 1 W = - (142127 mol)(8 . 314 J/(mol K))(150 + 273 K ) ln 16 . 66 100 = 8 . 958 × 10 8 J iii. Energy balance (integral form) for the closed system is: U 2 - U 1 = Q + W Back from homework 2, for an ideal gas, stating from equation 6.2-21, dU = C V dT + " T ∂P ∂T V - P # dV reduces to: dU = C V dT However, the process is isothermal, so dT = 0 Which gives: dU = Δ U = 1 N Δ U Therefore 0 = Q + W → Q = - W Q = - 8 . 958 × 10 8 J 3

Image of page 3

Explanation:As revealed above, the stimuli connections are clearly stated

Answer : The rate constant for this reaction is, [tex]3.65\times 10^{-3}Ms^{-1}[/tex]

Explanation :

To calculate the rate constant for zero order reaction, the expression used is:

[tex]\ln [A]=-kt+\ln [A_o][/tex]

where,

[tex][A_o][/tex] = initial concentration

[tex][A][/tex] = final concentration = [tex]5.00\times 10^{-2}M[/tex] at 195 s

[tex][A][/tex] = final concentration = [tex]2.50\times 10^{-2}M[/tex] at 385 s

k = rate constant = ?

Now put all the given values in the above expression, we get:

[tex]\ln (5.00\times 10^{-2})=-k\times 195+\ln [A_o][/tex]       ............(1)

and,

[tex]\ln (2.50\times 10^{-2})=-k\times 385+\ln [A_o][/tex]        ............(2)

Subtracting 1 from 2, we get:

[tex]\ln (2.50\times 10^{-2})-\ln (5.00\times 10^{-2})=-k\times 385+\ln [A_o]+k\times 195-\ln [A_o][/tex]

[tex]\ln (2.50\times 10^{-2})-\ln (5.00\times 10^{-2})=-k\times 385+k\times 195[/tex]

[tex]-0.693=-190k[/tex]

[tex]k=3.65\times 10^{-3}Ms^{-1}[/tex]

Therefore, the rate constant for this reaction is, [tex]3.65\times 10^{-3}Ms^{-1}[/tex]

The cell potential (Eocell) of the given reaction is 4.07V and the Gibbs free energy(∆Gorxn) is -785.42 KJ/mol suggesting the reaction occurs spontaneously and the cell in consideration is a voltaic cell.

To calculate the cell potential (Eocell), we use the formula Eocell = Eocathode - Eoanode. Here, for the reaction 2 Na+(aq) + 2 Cl−(aq)⟶2 Na(s) + Cl2(g), Na+ is being reduced to Na and Cl- is being oxidized to Cl2, therefore, Cl2 is the anode and Na+ is the cathode. So, the Eocell should be 1.36 V - (-2.71 V) = 4.07 V.

To calculate the Gibbs free energy (∆Gorxn), we use the formula ∆Gorxn = -n F Eocell, where n stands for the number of moles of electrons transferred in the redox reaction (which is 2) and F is the Faraday's constant (96500 C/mol). Therefore, ∆Gorxn = - (2 mol * 96500 C/mol * 4.07 V) = -785420 J/mol or -785.42 KJ/mol.

Since the E0cell value is positive, the reaction will occur spontaneously and represents a voltaic (or galvanic) cell which is a type of electrochemical cell where spontaneous redox reactions are used to convert chemical energy into electrical energy.

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Answer:

0.295 L

Explanation:

It seems your question lacks the final concentration value. But an internet search tells me this might be the complete question:

" A chemist must dilute 47.2 mL of 150. mM aqueous sodium nitrate solution until the concentration falls to 24.0 mM. He'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in liters. Be sure your answer has the correct number of significant digits. "

Keep in mind that if your value is different, the answer will be different as well. However the methodology will remain the same.

To solve this problem we can use the formula C₁V₁=C₂V₂

Where the subscript 1 refers to the concentrated solution and the subscript 2 to the diluted one.

And converting into L becomes:

Answer:

See explanation below

Explanation:

First, we need to write the overall reaction which is:

CH₃COOH + NaOH <---------> CH₃COONa + H₂O

The acetic acid, is a weak acid, so it has a acid constant (Ka) which is 1.75x10⁻⁵. Now that we know this, we can solve the problem by parts:

a) Initial pH:

In this case, the base is not added yet, so the only thing we have is the acetic acid in solution. So we'll do an ICE chart for the dissociation of the acetic acid:

       CH₃COOH + H₂O <-------> CH₃COO⁻ + H₃O⁺     Ka  = 1.75x10⁻⁵

i)        0.105                                      0                0

e)       0.105 - x                                 x                x

Writting the Ka expression:    Ka = [CH₃COO⁻] [H₃O⁺] / [CH₃COOH]  replacing:

1.75x10⁻⁵ = x² / 0.105 - x

As Ka is a very small value, we can assume that x will be very small too, so we can assume that 0.105 - x = 0.105:

1.75x10⁻⁵ = x² / 0.105

1.75x10⁻⁵ * 0.105 = x²

x = [H₃O⁺] = 1.35x10⁻³ M

Then, the pH:

pH = -log[H₃O⁺]

pH = -log(1.35x10⁻³)

pH = 2.87

b) volume to reach the equivalence point

In this case, we use the following expression:

M₁V₁ = M₂V₂

And solve for the volume:

V₂ = 0.105 * 24 / 0.13

V₂ = 19.38 mL of NaOH

c) pH with 6 mL of added base

In this case we need to see the moles of each substance and then see how many moles of the acid remain:

moles Acid = 0.105 * 0.024 = 2.52x10⁻³  moles

moles base = 0.130 * 0.006 = 7.8x10⁻⁴ moles

remaining moles of acid: 2.52x10⁻³ - 7.8x10⁻⁴ = 1.74x10⁻³ moles

With these moles, we can calculate the concentration assuming the volume is the sum of the 24 mL and the 6 mL of added base (30 mL)

M = 1.74x10⁻³ / 0.030 = 0.058 M

Now we will do the same thing we did in part a) with an ICE chart to calculate the H₃O⁺ concentration and then, the pH.

      CH₃COOH + H₂O <-------> CH₃COO⁻ + H₃O⁺     Ka  = 1.75x10⁻⁵

i)        0.058                                      0                0

e)       0.058- x                                  x                x

1.75x10⁻⁵ = x² / 0.058

1.75x10⁻⁵ * 0.058 = x²

x = 1.01x10⁻³ M

pH = -log(1.01x10⁻³)

pH = 3

d) at one half equivalence point

In this case, if the volume to reach equivalence is 19.38 mL, the half would be 9.69 mL, and now we will do the same thing as part c) but with these data:

moles Acid = 0.105 * 0.024 = 2.52x10⁻³  moles

moles base = 0.130 * 0.00969 = 1.26x10⁻³ moles

remaining moles of acid: 2.52x10⁻³ - 1.26x10⁻³ = 1.26x10⁻³ moles

With these moles, we can calculate the concentration assuming the volume is the sum of the 24 mL and the 9.69 mL of added base (33.69 mL)

M = 1.26x10⁻³ / 0.03369 = 0.037 M

          CH₃COOH + H₂O <-------> CH₃COO⁻ + H₃O⁺     Ka  = 1.75x10⁻⁵

i)        0.037                                      0                0

e)       0.037- x                                  x                x

1.75x10⁻⁵ = x² / 0.037

1.75x10⁻⁵ * 0.037 = x²

x = 8.05x10⁻⁴ M

pH = -log(8.05x10⁻⁴)

pH = 3.09

e) pH at equivalence point.

In this case the moles of the acid and the base are the same, therefore the pH would be higher than 7. so in this case we need to use the following expression:

pH = 7 + 1/2 pKa + 1/2log[CH₃COOH]

In this case the concentration of the acid in the equivalence point would be:

[C] = 2.52x10⁻³ / 0.04338 = 0.058 M

Applying the above expression:

pH = 7 + 1/2(-log(1.75x10⁻⁵) + 1/2log(0.058)

pH = 8.76

(a) The initial pH is approximately 2.87.

(b) The volume of added base required to reach the equivalence point is 18.46 mL.

(c) The pH at 6.00 mL of added base is approximately 4.74.

(d) The pH at one-half of the equivalence point is approximately 3.91.

(e) The pH at the equivalence point is approximately 8.39.

In the titration of acetic acid (CH3COOH) with sodium hydroxide (NaOH), the initial pH is determined by the concentration of the acetic acid before any base is added. Acetic acid is a weak acid, and its ionization in water results in the formation of hydronium ions (H3O+). The initial pH is calculated using the formula for weak acid dissociation, and for a 0.105 M solution of acetic acid, the initial pH is approximately 2.87.

The volume of added base required to reach the equivalence point is determined by stoichiometry, where the moles of base added equal the moles of acid initially present. Using the molarity and volume of the acid solution and the molarity of the base solution, the volume at the equivalence point is found to be 18.46 mL.

At 6.00 mL of added base, the pH is calculated by considering the remaining excess acid and the newly formed acetate ion. This involves solving the Henderson-Hasselbalch equation for a buffer system, resulting in a pH of approximately 4.74.

At one-half of the equivalence point, the pH is determined by finding the concentration of acetic acid and acetate ion in the solution. This is calculated using the initial concentration of acetic acid, the moles of base added, and the stoichiometry of the reaction. The pH at one-half of the equivalence point is approximately 3.91.

At the equivalence point, all the acetic acid has reacted with the sodium hydroxide, resulting in the formation of sodium acetate and water. The pH at the equivalence point is determined by the hydrolysis of the acetate ion. This results in a pH of approximately 8.39, indicating a basic solution due to the presence of excess hydroxide ions from the reaction.

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