List a few of the physical properties of graphite.

According to trends in the periodic table, the atomic radius decreases from left to right across a period. Therefore, potassium, being furthest to the left, would have the largest atomic radius followed by calcium and then scandium.

The subject of this question is the atomic radius of elements on the periodic table, specifically potassium, calcium, and scandium. The atomic radius generally decreases as you go from left to right across a period in the periodic table due to the increasing positive charge of the nucleus (i.e., the increasing atomic number), which draws the electrons closer to the nucleus, thereby decreasing the atomic radius.

In the case of potassium (atomic number 19), calcium (atomic number 20), and scandium (atomic number 21)

, potassium should have the largest atomic radius, followed by calcium, and then scandium with the smallest atomic radius.

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The enthalpy of formation of [tex]\rm MCl_3[/tex] will be -5849 kJ.

The given reactions represent:

Enthalpy of reaction of M with HCl = [tex]\rm \Delta H_1[/tex] = -556 kJ

Enthalpy of sublimation of HCl = [tex]\rm \Delta H_2[/tex] = -74.8 kJ

Enthalpy of HCl formation = [tex]\rm \Delta H_3[/tex] = -1845 kJ

Enthalpy of sublimation of [tex]\rm MCl_3\;=\;\Delta H_4[/tex] = -342.0 kJ

The enthalpy of formation of [tex]\rm MCl_3[/tex] will be: [tex]\rm \Delta H_5[/tex]

[tex]\rm \Delta H_5[/tex] = [tex]\rm \Delta H_1\;+\;6\;\times\;\Delta H_2\;+\;3\;\times\;\Delta H_3\;-\;2\;\times\;\Delta H_4[/tex]

= -550 + 6 (-74.8) + 3 (-1845) - 2 (342)

= -5849 kJ.

The enthalpy of formation of [tex]\rm MCl_3[/tex] will be -5849 kJ.

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Answer: C

Explanation: I got it right

The formula for the conjugate base of the strong acid HClO₄ (perchloric acid) is ClO4⁻.

The conjugate base of an acid is formed when the acid donates a proton (H+) to a base. In the case of perchloric acid (HClO₄), the conjugate base is derived by removing the acidic hydrogen ion (H+) from the acid.

The formula for the conjugate base of HClO₄, known as perchlorate ion, is ClO₄-. The perchlorate ion has a negative charge (-1) due to the loss of the hydrogen ion from the acid.

The perchlorate ion is the conjugate base of perchloric acid. Its chemical formula is ClO4-. The perchlorate ion consists of one chlorine atom (Cl) bonded to four oxygen atoms (O) in a tetrahedral arrangement.

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Answer : The heat capacity in joules per degree Celsius and calories per degree Celsius is, [tex]47.6J/^oC[/tex] and [tex]11.4cal/^oC[/tex] respectively.

Explanation : Given,

Mass of nitrogen gas = 45.8 g

Heat capacity of nitrogen gas = [tex]1.04J/g^oC[/tex]

First we have to calculate the heat capacity in joules per degree Celsius.

As, 1 gram of nitrogen gas has heat capacity = [tex]1.04J/^oC[/tex]

So, 45.8 gram of nitrogen gas has heat capacity = [tex]45.8\times 1.04J/^oC=47.6J/^oC[/tex]

Thus, the heat capacity in joules per degree Celsius is [tex]47.6J/^oC[/tex]

Now we have to calculate the heat capacity in calories per degree Celsius.

As we are given the conversion:

[tex]1cal=4.184J\\\\1J=\frac{1}{4.184}cal[/tex]

So, the heat capacity of nitrogen gas = [tex]\frac{1}{4.184}cal\times 47.6\text{ per }^oC=11.4cal/^oC[/tex]

Thus, the heat capacity in calories per degree Celsius is [tex]11.4cal/^oC[/tex]

The heat capacity, in Joules per degree Celsius and in calories per degree Celsius are 47.632 J/g°C and 11.384 cal/g°C respectively.

Given the following data:

To find the heat capacity, in Joules per degree Celsius and in calories per degree Celsius:

By direct proportion:

1 gram of nitrogen gas = 1.04 J/g°C

45.8 grams of nitrogen gas = X J/g°C

Cross-multiplying, we have:

[tex]X = 45.8 \times 1.04[/tex]

X = 47.632 J/g°C.

Therefore, the heat capacity, in Joules per degree Celsius, for 45.8 grams of nitrogen gas is 47.632 J/g°C.

In calories per degree Celsius:

1 calorie = 4.184 Joules

Y calorie = 47.632 Joules

Cross-multiplying, we have:

[tex]Y \times 4.184 = 47.632\\\\Y = \frac{47.632}{4.184}[/tex]

Y = 11.384 cal/g°C.

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Answer:

To prepare a supersaturated solution, the added amount must be higher than the solubility for the given volume of solvent

Explanation:

Hello,

This could be answered by knowing that all the solutes have a property called solubility which accounts for the maximum amount of it that can be thoroughly dissolved into a specific solvent. Thus, to prepare a supersaturated solution, the added amount must be higher than the solubility for the given volume of solvent at a specific temperature. For example, at 20°C, 45.8g of aluminium chloride are completely dissolved into 100 mL of water, so at that amount, the solution will be saturated, thus, if one adds more than 45.8g the solution will start being supersaturated.

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In this situation, the listening process stage being implemented is 'evaluating'. Janie's mom is assessing the details of the party and deciding about its validity and reliability, which indicates this stage.

In the given scenario, the stage of the listening process that is taking place is evaluating. The event happens as Janie's mom listens to Janie's account of the party and makes a judgment about it. It means she's weighing the information she has received and is deciding on its validity and reliability. After listening to the information, she makes an evaluation that requires her to speak to Reeve's parents first before making a decision. This is the evaluating stage, where she is assessing and judging the information she has received.

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The structure of B is

         H

         |

   H3C - C ≡ N

         |

         H

The reaction of (R)-2-butanol with phosphorus tribromide (PBr3) undergoes substitution reaction, replacing the hydroxyl group with a bromine atom, resulting in compound A, which is 2-bromobutane (C4H9Br).

Compound A is then treated with sodium cyanide (NaCN) in dimethylformamide (DMF), undergoing a nucleophilic substitution reaction. The cyanide ion replaces the bromine atom, forming compound B, which is 2-butyne nitrile (C5H9N).

Compound B is optically active due to the presence of the chirality at the carbon atom adjacent to the nitrile group. The carbon atom bonded to the nitrogen and the two methyl groups creates a chiral center, resulting in optical activity.

The specific rotation of B would depend on the configuration of the chiral carbon.

Complete Question:

(R)-2-butanol reacts with phosphorus tribromide to give A (C_4H_9Br). Treatment of A with sodium cyanide in DMF gives B (C_5H_9) N. B is optically active. Draw the structure of B.

The integrated rate law for a second-order reaction is given by:

[tex] \frac{1}{[A]t} = \frac{1}{[A]0} + kt [/tex]

where, [A]t= the concentration of A at time t,

[A]0= the concentration of A at time t=0

k = the rate constant for the reaction

Given: [A]0= 4 M, k = 0.0265 m–1min–1 and t = 180.0 min

Hence, [tex] \frac{1}{[A]t} = \frac{1}{4} + (0.0265 X 180) [/tex]

                                        = 4.858

Therefore, [A]t= 0.2058 M.

Answer: Concentration of A, after 180 min, is 0.2058 M

The reaction rate for H₂O₂(aq) + I₂(aq) ⇌ OH⁻(aq) + HIO(aq) increases by a factor of 6 when the concentration of H₂O₂ is increased by half and the concentration of I₂ is quadrupled.

The rate of a reaction is influenced by the concentrations of the reactants. For the reaction H₂O₂(aq) + I₂(aq) ⇌ OH⁻(aq) + HIO(aq), the rate law is given by: Rate = k[H₂O₂][I₂]

This indicates that the reaction is first order with respect to both H₂O₂ and I₂.

Step-by-Step Explanation:

Rate increase factor = (k(1.5[H₂O₂]₀)(4[I₂]₀)) / (k[H₂O₂]₀[I₂]₀) = 1.5 * 4 = 6.

Therefore, the reaction rate increases by a factor of 6.

To determine which concentration(s) will have increased when the mixture reaches equilibrium, we can compare the reaction quotient (Qc) to the equilibrium constant (Kc):

N2(g)   +  3  H2(g) =  2NH3(g)

Qc =  (NH3^2)   / { (N2)(H)^3)}

Qc=  0.48^2  /{ ( 0.60) (0.760^3) }=  0.875

Qc < Kc  therefore  the  equilibrium  will   shift     to  the  right.  This  implies  that  Nh3  concentration  will    increase    

Calculate Qc using the initial concentrations and the balanced chemical equation.

Compare Qc to Kc:

If Qc < Kc, the reaction will proceed to the right (towards products) to reach equilibrium.

If Qc > Kc, the reaction will proceed to the left (towards reactants) to reach equilibrium.

In this case, if Qc is less than Kc, it indicates that the concentrations of products ([NH₃]) will increase, and the concentrations of reactants ([N₂] and [H₂]) will decrease when the mixture reaches equilibrium.

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Final answer:

The mass of oxygen gas that reacted with the iron nail to form rust was 43 grams, which is the difference between the original mass of the iron nail (100g) and the mass after rusting (143g).

Explanation:

The mass of oxygen gas that most likely reacted with the iron nail to produce rust can be calculated by finding the difference in mass before and after the rusting process. Initially, the mass of the iron nail was 100g, and after rust formation, the mass increased to 143g. The increase in mass is due to the oxygen from the air reacting with the iron to form rust, which consists of hydrated iron(III) oxide.

Therefore, the mass of the oxygen that reacted with the iron nail can be calculated as follows:

Mass of rusted nail - Original mass of iron nail = Mass of oxygen

143g - 100g = 43g

Thus, 43 grams of oxygen reacted with the iron nail to form rust.

Answer is:

CH₃-CH₂-CH₂-NH₂ + H₂O(l) ⇄ CH₃-CH₂-CH₂-NH₃⁺(aq) + OH⁻(aq).

Amine group (-NH₂) has neutral charge, bet when accepts one proton (H⁺) has positive charge.
Amines are compounds that contain a basic nitrogen atom with a lone pair of electrons. Amines are derivatives of ammonia, where is one or more hydrogen atoms replaced by a substituent such as an alkyl or aryl group (in this compound propyl group).

Propylamine accepts a proton from water according to the reaction equation; C3H7NH2(aq) + H2O(l) ------> C3H7NH3^+(aq) + OH^-

Propylamine is a base because it accepts a proton. Recall that according to Brownstead - Lowry, a base is any substance that accepts a proton while an acid is any substance that donates a proton. Propylamine accepts a proton because of the lone pair on nitrogen atom.

The reaction of propylamine with water is an acid base reaction because propylamine accepts a proton from water as follows;

C3H7NH2(aq) + H2O(l) ------> C3H7NH3^+(aq) + OH^-

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Answer:

1. Incorrect, it occurs in gases as well or generally in fluids.

2. Correct.

3. Incorrect.

Explanation:

Hello,

1. Convection, is a heat transport phenomena which occurs when a fluid transfers energy in the form of heat to a surface or vice-versa, in such a way, it occurs fluid, say, in both gases and liquids.

2. In this case, radiation is a heat transfer phenomena which occurs by thermal waves transferring the heat; such waves are generated by a hot body which it is said to irradiate the waves by cause of its inner temperature, therefore, as it could be surrounded by a colder space, heat is transferred. As a result of the high temperature, all substances could radiate heat.

3. In this case, it is widely known that normal temperature is between 20 and 25 ºC while the body's inner temperature is about 37 ºC for our organism to work properly. In such a way, those temperatures are different.

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We use the expression for Kp in terms of partial pressures, set up an equation incorporating the given initial pressures and the changes in pressure that occur as the reaction proceeds, and solve that equation to find the equilibrium partial pressure of CO2.

To answer this question, we need to use the expression for the equilibrium constant (Kp) in terms of partial pressures. Kp is defined as the ratio of the products of the partial pressures of the products, each raised to their stoichiometric coefficients in the balanced chemical equation, to the product of the partial pressures of the reactants, each raised to the power of their stoichiometric coefficients. Based on this, the expression is:

Kp = (pCO2 * pH2) / (pCO * pH2O)

where pCO, pH2O, pCO2 and pH2 are the equilibrium partial pressures of CO, H2O, CO2 and H2 at equilibrium, respectively. We know that initially, the partial pressure of CO2 and H2 is 0 because the reaction has not yet occurred. Also, the initial partial pressures of CO and H2O are given as 1320 torr and 1760 torr respectively.

As reaction proceeds to the right, the pressures of CO and H2O will decrease while that of CO2 and H2 will increase. Let's assume the decrease in the pressures of CO and H2O is by x.

Therefore, at equilibrium:

So, plug these values into the Kp expression we get:

0.0611 = (x*x) / {[1320 - x]*[1760 - x]}

Solving this quadratic equation will give the value of x.

Substituting 'x' in pCO2 = x will give us the equilibrium partial pressure of CO2.

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The equilibrium partial pressure of CO2 in a chemical reaction can be calculated using an ICE table and the given Kp value in the application of Le Chatelier's principle.

The subject of this question is the calculation of the equilibrium partial pressure of CO2 in a chemical reaction according to Le Chatelier’s principle. We first identify the given Kp value and initial partial pressures for CO and H20. Using the equation for the reaction, CO(g) + H2O(g) ⇌ CO2(g) + H2(g), we can create an ICE (Initial, Change, Equilibrium) table to track changes in the partial pressures during the reaction. As the reaction proceeds, the concentrations of CO and H2O decrease while those of CO2 and H2 increase until equilibrium is reached. The changes for CO and H2O are negative while those for CO2 and H2 are positive. Using the equilibrium expressions and the given Kp value, we can solve for the change and add this to the initial concentrations to get the equilibrium concentrations.

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Final answer:

The pH of a 0.750 M KH₂PO₄ solution cannot be accurately determined without additional information such as the pKa value of the dihydrogen phosphate ion (H₂PO₄₋).

Explanation:

The pH of a solution of 0.750 M KH₂PO₄, potassium dihydrogen phosphate, depends on the acid dissociation constants of phosphoric acid (H₃PO₄), as KH₂PO₄ is its conjugate salt. Typically, to calculate the pH of such a solution, one would use the Henderson-Hasselbalch equation which relates the pH of a buffer solution to the pKa of the acid and the concentrations of the acid and its conjugate base.

However, because there is no other species like phosphoric acid or its other salts present to form a buffer system, and because H₂PO₄₋ (from dissociation of KH₂PO₄) is a weak acid, we may need to approach this problem differently.

Since the direct calculation of pH in this context isn't possible without additional information such as the pKa value of the dihydrogen phosphate ion (H₂PO₄⁻), and because the problem does not ask for assumptions to be made or provide a relevant pKa value, the task cannot be completed.

In practical applications, a pKa value would be required to use the Henderson-Hasselbalch equation, or for the weak acid formula: pH = -log[H⁺] where [H⁺] can be obtained through the equilibrium expression involving the dissociation constant (Ka) and the concentration of H₂PO₄⁻.

To calculate the volume of 10.0 M HCl needed to exhaust the remaining capacity of the buffer, determine the moles of TrisHCl remaining after adding hydrogen ions and use stoichiometry to calculate the required volume.

To calculate the additional volume of 10.0 M HCl needed to exhaust the remaining capacity of the buffer, we need to determine the number of moles of TrisHCl that remain after adding 0.0200 mol of hydrogen ions to half of the buffer. This will give us the amount of TrisHCl that needs to be neutralized. From there, we can calculate the volume of 10.0 M HCl needed to neutralize the remaining TrisHCl.

The calculated volume will be the additional volume of 10.0 M HCl needed to exhaust the remaining capacity of the buffer.

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An additional 18 mL of 10.0 M HCl is required to exhaust the remaining capacity of the buffer. This is determined by calculating the amount of Tris that remains unreacted and can further neutralize HCl.

What additional volume of 10.0 M HCl would be needed to exhaust the remaining capacity of the buffer after the reaction described in Part B?

First, we need to understand the capacity of the buffer system. From Part A, we have 31.52 g of TrisHCl.

Step 1: Calculate the moles of TrisHCl.

Step 2: Calculate the initial moles of Tris (conjugate base) and TrisH+ (conjugate acid).

Step 3: Determine the remaining capacity to neutralize more HCl.

Step 4: Calculate the volume of 10.0 M HCl needed to exhaust the buffer.

Therefore, an additional 18 mL of 10.0 M HCl is required to exhaust the remaining capacity of the buffer.

Sulfuric acid ionizes in two steps, each releasing a hydrogen ion to form first the bisulfate ion and then the sulfate ion. The first is H2SO4 (aq) → H+ (aq) + HSO4- (aq) and the second is HSO4- (aq) → H+ (aq) + SO4^2- (aq).

The ionization of sulfuric acid (H2SO4) in water occurs in two steps. Each step involves the release of a hydrogen ion (H+), and the corresponding production of the hydronium ion (H3O+) is generally implied when the acid ionizes in aqueous solution.

First Ionization: H2SO4 (aq) → H+ (aq) + HSO4- (aq).This is the first ionization step where one hydrogen ion is released, creating the bisulfate ion (HSO4-).

Second Ionization: HSO4- (aq) → H+ (aq) + SO4^2- (aq). In the second ionization step, the bisulfate ion (HSO4-) releases a second hydrogen ion, resulting in the sulfate ion (SO4^2-).

Both of these equations are balanced chemical equations that depict the stepwise ionization of sulfuric acid and the formation of its conjugate bases.

The balanced chemical formula for lead(IV) sulfide is PbS₂, not Pb₂S₄. This correctly balances lead's +4 charge with two sulfur atoms, each with a -2 charge.

Lead(IV) sulfide is a chemical compound consisting of lead (Pb) and sulfur (S). The Roman numeral IV indicates that lead has an oxidation state of +4 in this compound. Sulfur commonly has an oxidation state of -2.

To form a neutral compound, we need to balance the charges. Lead(IV) has a charge of +4, and sulfur has a charge of -2. Therefore, it takes two sulfur atoms to balance one lead atom.

The balanced chemical formula for lead(IV) sulfide is PbS₂, not Pb₂S₄. The latter formula incorrectly represents the proportions since it can be simplified to PbS₂, as both share the same ratio.

Thus, the correct balanced chemical formula is PbS₂.

Answer:

Fire extenguisher and refrigerator

Explanation:

Refrigerator : There are 5 basic components in refrigeration I.e. fluid refrigerant, a compressor which controls the flow of refrigerant; the condensor coil( on the outside of the fridge), evaporation coils( on the inside of the fridge) and something calls an expansion device.

Fire Extinguishers: Water performs two functions; its conversion tosteam absorbs the heat, and the steam displaces the air from the vicinity of the flame. Many siimple fire extinguishers  are quipped with hand pumps or sources of compressed gas to propel water through the nozzle.

Hydraulic systems and water turbines are two fluid technologies that make use of water. Hydraulic systems use water or other fluids to transmit force or energy, while water turbines use the flow of water to generate mechanical energy and produce electricity.

Two fluid technologies that make use of water are hydraulic systems and water turbines.

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