Please help. The answer is 55.40g of Na but I need to get the equation to get it.
2 Na (s) + 2 H2O (l) → 2 NaOH (aq) + H2 (g)

If 27L of H2 was produced, what was the reactant mass of sodium?
55.40g Na

To calculate the energy of the photon emitted for Element Y, you can use the following equation:
E = hc/λ
where h is Planck's constant (6.626 x 10-34 Js), c is the speed of light (3 x 108 m/s), and λ is the wavelength of the photon (in meters).

To calculate the wavelength of the photon emitted for Element Y, you can use the following equation:
λ = hc/E
where h is Planck's constant (6.626 x 10-34 Js), c is the speed of light (3 x 108 m/s), and E is the energy of the photon (in Joules)

To calculate the frequency of the photon emitted for Element Y, you can use the following equation:
f = c/λ
where c is the speed of light (3 x 108 m/s), and λ is the wavelength of the photon (in meters).

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(a) The pH of pure water is 7, which is neutral. (b) The universal indicator would show a yellow color in an aqueous solution of sugar, because sugar is a neutral compound with a pH of 7.(c) The pH of the rain water is likely around 5 or 6, which indicates a weak acid.

pH is less than 7 since yellow color indicates acidic rainwater. Rainwater has an acidic pH because it dissolves atmospheric carbon dioxide (CO2), sulfur dioxide (SO2), and nitrogen oxides (NOx), forming weak carbonic, sulfuric, and nitric acids.

Rainwater that has a pH below 5.6 is considered to be acid rain. Therefore, the acid present in rainwater is a weak acid because the pH of the rainwater is above 1.

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Answer:

7.5g is the mass of potassium nitrate that will dissolve in 25g of water at 20° C?

The answer is 4g. At 20° C, the solubility of potassium nitrate in water is 3.7 g per 100 g of water, which means that about 4 g of potassium nitrate will dissolve in 25 g of water.

Solubility is the ability of a substance to dissolve in a liquid or other solvent. It is a measure of the maximum amount of substance that can be dissolved in a given amount of solvent. Solubility can be affected by factors such as temperature, pressure, and the type of solvent used. In general, the more soluble a substance is, the more easily it will dissolve. Solubility is an important factor in the formulation of many products, such as pharmaceuticals, cosmetics, and food products. It is also used in the manufacture of detergents, paints, and inks. Solubility can be determined experimentally, by measuring the amount of a substance that can be dissolved in a given volume of solvent. The solubility of a substance can also be calculated using equations that take into account the temperature and pressure of the system. Understanding solubility is important for determining the effectiveness of drugs, the shelf life of food products, and the environmental impact of certain chemicals.

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You need to know the molar mass of calcium chloride in order to calculate the moles of calcium chloride with a mass of 1.11 g. The total atomic masses of all the atoms in a single compound molecule make up the molar mass.

According to its chemical formula, calcium chloride is composed of two chlorine atoms (atomic mass = 35.45 g/mol) and one calcium atom (atomic mass = 40.08 g/mol). As a result, calcium chloride has the following molar mass:

CaCl2 has a molar mass of 110.98 g/mol (40.08 g/mol + 2 x 35.45 g/mol).

The number of moles of calcium chloride having a mass of 1.11 g may be determined using the molar mass of calcium chloride, which we already know. The following is the formula to get the number of moles:

Molar mass divided by mass equals a mole.Substituting the values we know, we get:

moles of CaCl2 = 1.11 g / 110.98 g/mol = 0.01 mol

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There are 4 chirality centers in an aldohexose. The correct answer is option b.

Aldohexoses are six-carbon monosaccharides with a carbonyl functional group (aldehyde group) and five other carbon atoms, each of which is associated with an alcohol functional group in their straight-chain form. The carbonyl carbon, which is referred to as the anomeric carbon, determines the stereochemistry and the cyclic form of aldohexoses.

Chirality centers are carbon atoms that have four distinct substituents bonded to them, resulting in the ability to exist as stereoisomers. These stereoisomers are mirror images of each other and cannot be superimposed upon each other.Therefore, it is important to count the number of chirality centers present in the aldohexose structure.

There are four chirality centers in aldohexose, which are present at carbon atoms 2, 3, 4, and 5.

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The complex that will absorb a photon with the lowest energy is [Co(OH)6]3-. The correct answer is option A

Co(OH)6]3- is the complex that absorbs a photon with the lowest energy. It is because of the crystal field effect. The complex [Co(OH)6]3- has the lowest energy for the d-electrons of the cobalt ion. A photon is an elementary particle that forms a light beam. It has a small mass and no charge. A photon has wave-particle duality, which means it exhibits properties of both a wave and a particle. Photons are electromagnetic radiation particles, which means they have both electric and magnetic components.

The lowest energy is defined as the minimum energy that a system can have. It is the energy state that is energetically stable. Photons have energy, and the energy of the photon is directly proportional to its frequency. The energy of a photon can be used to determine the energy of the electron that absorbs it.

A weak field ligand environment means that there is a small energy gap between the t2g and eg orbitals. As a result, it absorbs photons with the lowest energy, according to the spectrochemical series. In comparison to the other complexes, [Co(OH)6]3- has a low-energy gap, which makes it the most stable.

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When 0.1 M HCl and 0.1 M NaOH are combined in equal amounts, a process known as neutralisation will take place, producing water and a salt as byproducts.

In a neutralisation process, which takes place when an acid and a base are mixed, the H+ ions from the acid and the OH- ions from the base combine to generate water molecules. In this instance, when 0.1 M HCl and 0.1 M NaOH are combined in equal parts, they will react 1:1 to form water and the salt NaCl. The final mixture's pH will be 7, which is neutral. This is due to the fact that only water and salt are left after the reaction, totally consuming the H+ and OH- ions. A lot of industries, including industry, agriculture, and medicine, utilise this kind of reaction.

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The stereocenter-containing molecule is:

1,2-dimethylcyclohexane (both carbons at position 1 and 2 are stereocenters as they have four distinct substituents connected to them)

(both carbons at position 1 and 2 are stereocenters as they have four different substituents attached to them)

Stereocenters are absent from the other compounds that were listed. Because the double bond does not include any substituents that are distinct from one another, the alkene with H wedges and the CH3 dash does not have stereocenters. As all of the carbons in cyclohexane are symmetric and do not have four separate substituents connected to them, the cyclohexane with wedge-dash methyl likewise lacks stereocenters., the only molecule in the list that contains stereocenters is 1,2-dimethylcyclohexane.

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Answer:

jkhihjijhbjbjk

true

Explanation:

Atoms cannot be subdivided, created, or destroyed. Atoms of different elements can combine in simple whole number ratios to form chemical compounds.

Answer:

true

hdozhsienzidbxirbfifndirhfirbr

A solution is prepared by dissolving 1.0 g of NaOH in a total of 250 mL of solution. Then 10.0 mL of this solution is withdrawn and added to 90.0 mL of water. The pH of the final solution is 11. Here option D is the correct answer.

To determine the pH of the final solution, we need to calculate the concentration of hydroxide ions (OH-) first.

1.0 g of NaOH is dissolved in a total volume of 250 mL of solution, which is equivalent to 0.004 moles of NaOH (since the molar mass of NaOH is 40.0 g/mol). Therefore, the concentration of NaOH in the original solution is:

c(NaOH) = 0.004 moles / 0.250 L

= 0.016 M

When 10.0 mL of this solution is added to 90.0 mL of water, the resulting concentration of NaOH is diluted by a factor of 10. Therefore, the concentration of NaOH in the final solution is:

c(NaOH) = 0.016 M / 10

= 0.0016 M

Since NaOH is a strong base, it completely dissociates in water to form one mole of hydroxide ions (OH-) for every mole of NaOH. Therefore, the concentration of hydroxide ions in the final solution is also 0.0016 M.

To calculate the pH of the solution, we use the following equation:

pH = 14 - pOH

Since the concentration of hydroxide ions is 0.0016 M, the pOH is:

pOH = -log[OH-]

= -log(0.0016)

= 2.80

Therefore, the pH of the solution is:

pH = 14 - pOH

= 14 - 2.80

= 11.20

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For the weak acid, the expression for the acid ionization constant Ka is given by the equation O Ka = [H3O+](HSO3) /H2SO3.

How to find acid ionization constant Ka?

The acid ionization constant Ka of a weak acid HA is given by the equation shown below, where [H3O+] represents the hydrogen ion concentration of the solution, and [A-] represents the conjugate base of the acid. Ka = [H3O+][A-]/[HA]

It is possible to calculate the acid dissociation constant of a weak acid by measuring the degree of ionization of the acid. A higher degree of ionization indicates a stronger acid, while a lower degree of ionization indicates a weaker acid.

The acid ionization constant Ka is used to compare the strengths of various acids.

The correct option is O Ka = [H3O+](HSO3) /H2SO3). The acid ionization constant Ka for a weak acid is the equilibrium constant for the ionization reaction of the acid. The acid ionization constant for a weak acid, Ka, is expressed as:

Ka = [H3O+][A-]/[HA]

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Answer:

A)law of multiple proportions

Explanation:

The complete radioactive decay equation is as follows:

234/92 → 4/2He + 230/90 Th

Radioactive decay is a several processes by which unstable nuclei emit subatomic particles and/or ionizing radiation and disintegrate into one or more smaller nuclei.

According to this question, uranium with the mass number 234 and atomic number 92 undergoes a radioactive decay as follows:

234/92 U → 4/2 He + 230/90 Th

Uranium-234 nuclei decay by alpha emission to thorium-230, except for the tiny fraction (parts per billion) of nuclei that undergo spontaneous fission.

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A spontaneous reaction under standard conditions is indicated by the value of K being greater than 1. Thus, the answer to the given question is option C, K = 2.2 x 10².

Standard conditions- Standard conditions are a set of environmental conditions that are considered to be the standard conditions for conducting an experiment. They serve as a reference point to compare the effects of varying environmental conditions on the properties of a substance or the results of an experiment.

Standard conditions in chemistry are considered to be a temperature of 298K (25°C), a pressure of 1 atm (101.3 kPa), and a concentration of 1 mol/L (for solutions).

Spontaneous reaction- A spontaneous reaction is one that proceeds without any external force or intervention. That is, a spontaneous reaction proceeds without the need for energy input from an external source. In other words, it is an exothermic reaction where the products are more stable than the reactants.

The Gibbs free energy change of a spontaneous reaction is negative. The sign of ΔG indicates the spontaneity of a reaction. A negative value indicates that the reaction is spontaneous, whereas a positive value indicates that the reaction is non-spontaneous. The value of ΔG° is used to determine the spontaneity of a reaction under standard conditions.

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The correct answer is D.

A strong base is a substance that completely dissociates into its ions in water, producing a high concentration of hydroxide ions (OH-). Similarly, a weak base is a substance that only partially dissociates into its ions in water, producing a low concentration of hydroxide ions (OH-).

The term that completes the analogy is "Weak electrolyte", which is a substance that only partially dissociates into its ions in water and conducts electricity poorly. A strong electrolyte, on the other hand, is a substance that completely dissociates into its ions in water and conducts electricity well.

Therefore, the analogy can be completed as follows:

"Strong base is to weak base as strong electrolyte is to weak electrolyte."

I hope it helped you :)

Answer: d. possessing tiny protrusions known as microvilli. The proximal convoluted tubule's epithelial cells have microvilli on their surface, which increases their surface area and improves.

the efficiency of reabsorption of chemicals from the filtrate back into the circulation. The cells do not release enzymes to promote absorption, and the rugae folds and thin walls are not adaptations for reabsorption. The proximal convoluted tubule's epithelial cells are in charge of reabsorbing vital components from the glomerular filtrate, including glucose, amino acids, and electrolytes. Many microvilli, which are tiny finger-like projections on the surface of the cell that enhance the surface area accessible for reabsorption, are present in the cells, which enable them to perform this role. This modification makes it possible for chemicals to be reabsorbted more effectively as they move through the tubule. The rugae folds and thin walls, on the other hand, have little impact on reabsorption in the proximal convoluted tubule. In this region of the nephron, reabsorption likewise does not include enzyme secretion.

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Gamma radiation are the most dangerous type of radioactive emission as they are the most energetic and can penetrate the human body and damage cells. Alpha particles can cause both short-term and long-term health effects, such as cancer.

Out of alpha, beta and gamma radiation, the most dangerous type of radioactive emission is gamma radiation. This is because gamma rays are penetrating, high-energy rays that can easily penetrate the human body and cause damage to cells and DNA. Gamma radiation, unlike alpha and beta radiation, can penetrate the body's skin and tissue, exposing internal organs to radiation. When gamma rays are absorbed by living cells, they can ionize atoms and molecules, causing damage to DNA and other genetic material in the cell. High doses of gamma radiation can cause immediate symptoms such as radiation sickness and even death. Gamma radiation is frequently emitted by unstable radioactive atoms like uranium and plutonium, which are used in nuclear power plants and nuclear weapons. Workers in these industries and anyone exposed to a nuclear accident or bomb are at a higher risk of exposure to gamma radiation. Alpha radiation is a type of ionizing radiation that is emitted by certain types of unstable atoms. Alpha particles are relatively large and have a short range, so they can be stopped by a sheet of paper or the outer layer of human skin. Beta radiation is a type of ionizing radiation that is emitted by certain types of unstable atoms. Beta particles are much smaller than alpha particles, and they can travel through the human body farther than alpha particles. Gamma radiation is a type of electromagnetic radiation, similar to X-rays, but with higher energy and frequency. Gamma rays are produced by the decay of unstable atomic nuclei and are highly penetrating, meaning they can easily pass through solid objects.

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Answer:

oxygen friend

Explanation:

It is generally believed that the Earth's atmosphere did not contain oxygen until around 2500 million years ago (Mya) when oxygen-evolving photosynthetic bacteria arose. At around 800–500 Mya, the oxygen concentration increased sharply to reach the 21% we have today. So, it seems highly likely that life arose as anaerobic organisms, which then evolved to tolerate oxygen and finally, to use it as a terminal acceptor for the energy-producing oxidative processes in the respiration of aerobic bacteria and mitochondria in eukaryotic cells. The respiratory processes employed by typical aerobic organisms today have a wide range of mechanisms to deal with the troublesome side effects of living with a high oxygen concentration.

To determine the limiting reactant, amounts of each product formed, and the amount by which the excess reactant is for a reaction between 12.0 grams of NH₃ and 15.0 grams of O₂, the balanced chemical equation and stoichiometry must be used.

The balanced chemical equation for the reaction between NH₃ and O₂ is:

4NH₃ + 5O₂ → 4NO + 6H₂O

To determine the limiting reactant, the amounts of reactants must be converted to moles. The molar mass of NH3 is 17.03 g/mol and the molar mass of O₂ is 32.00 g/mol.

12.0 g NH₃ × (1 mol NH3/17.03 g NH₃) = 0.705 mol NH

315.0 g O₂ × (1 mol O2/32.00 g O₂) = 0.469 mol O₂

The stoichiometry of the balanced chemical equation indicates that 4 moles of NH₃ reacts with 5 moles of O₂. The mole ratio of NH₃ to O₂ is 4/5 or 0.8. Since the mole ratio of NH₃ to O₂ is greater than the actual mole ratio of 0.705/0.469 or 1.50, NH₃ is the excess reactant and O₂ is the limiting reactant.

To determine the amount of each product formed, the mole ratio of products to limiting reactant must be used. The mole ratio of NO to O₂ is 4/5 or 0.8, and the mole ratio of H₂O to O₂ is 6/5 or 1.2. Since O₂ is the limiting reactant, the amount of NO and H₂O that can be produced is based on the mole ratio to O₂.

0.469 mol O₂ × (4 mol NO/5 mol O₂) × (30.01 g NO/1 mol NO) = 0.601 g NO

0.469 mol O₂ × (6 mol H₂O/5 mol O₂) × (18.02 g H₂O/1 mol H₂O) = 0.674 g H₂O

The amount of excess NH₃ is determined by subtracting the moles of NH₃ used from the moles of NH₃ added.

0.705 mol NH₃ − (0.469 mol O₂ × 4 mol NH₃ / 5 mol O₂) = 0.408 mol NH₃

Thus, the limiting reactant is O₂, 0.601 g NO and 0.674 g H₂O are produced, and there is 0.408 mol of excess NH₃.

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The correct answer is D. [tex]CO_3^{2-}(aq) + H_ 2O(l) \rightleftharpoons  HCO_3^-(aq) + OH^-(aq)[/tex]. This chemical equilibrium equation best shows what happens in the buffer solutions to minimize the change in pH when a small amount of a strong base is added.

Buffer solutions containing [tex]Na_2CO_3[/tex] and [tex]NaHCO_3[/tex] range in pH from 10.0 to 11.0. The chemical equation given represents the equilibrium between [tex]CO_3^{2-}[/tex] and [tex]H_2O[/tex], and the table lists the composition of four different buffer solutions at 25°C. When a small amount of a strong base is added to a buffer solution, the pH will start to increase. This equation helps to minimize the change in pH by shifting the equilibrium so that the concentration of [tex]HCO_3^-[/tex] is increased. This decreases the concentration of [tex]OH^-[/tex] and the pH increases less than it would if the equilibrium had not shifted.

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The new volume of the helium gas sample will be  124 ml. This is due to the fact that when the temperature decreases while the pressure remains constant, the volume of a gas will increase.

According to Charles’s law, the volume of a given gas at a constant pressure is directly proportional to its absolute temperature. Therefore, a decrease in temperature, while holding constant the pressure of the helium gas, would result in a decrease in volume.

A constant pressure is the one under which the pressure of a substance remains unchanged as the temperature and/or volume of the substance change. Charles's law may be used to explain the properties of gases, particularly with constant pressure since it states that the volume of a given mass of a gas is directly proportional to its absolute temperature, provided that its pressure remains constant. It's written as:V1/T1 = V2/T2; whereV1 = 620 ml; T1 = 500K; T2 = 100KLet's put the values in the formula given above. The [tex][tex]620/T1 = V2/100V2 = 62,000/500V2 = 124 ml[/tex].[/tex]Therefore, the new volume of helium gas at a temperature of 100K would be 124 ml.

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The structure of the resulting compound from the reaction of NO and NO2 is the compound is known as dinitrogen pentoxide, N2O5.The bond energy in NO is about 631 kJ/mol.The bond energies in NO2 are both about 240 kJ/mol.

N2O5 is the chemical formula for dinitrogen pentoxide, often known as nitrogen pentoxide or nitric anhydride. It belongs to the family of chemicals known as binary nitrogen oxides, which simply consists of nitrogen and oxygen. It exists as colourless crystals that sublimate at a temperature just above ambient to produce a colourless gas. Dinitrogen pentoxide, an unstable and potentially harmful oxidant, was originally employed as a reagent for nitrations when dissolved in chloroform, but nitronium tetrafluoroborate has completely replaced it (NO2BF4).

N2O5 is a rare instance of a substance that can change its structure based on the environment. The solid is a salt, nitronium nitrate, consisting of distinct nitronium cations [NO2]+ and nitrate anions [NO3]−; although in the gas phase and under some other situations  it is a covalently-bound molecule.

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The volume of the dry gas at STP when a 32.0 mL sample of hydrogen is collected over water at 20.0 degrees Celsius and 750.0 torr is 31.1 mL.

There is a formula used to calculate the volume of dry gas at STP given a sample of hydrogen gas collected over water at a specific temperature and pressure, which is as follows:

Vd = Vw - Vh2o

Vd = volume of the dry gas, Vw = volume of the wet gas, Vh2o = vapor pressure of water at a given temperature

The next thing is to calculate Vw which is the volume of the wet gas.

Vw = Vtotal - Vh2o

Vtotal = total volume of the gas collected, Vh2o = volume of the water collected

In the question, the volume of the hydrogen gas collected over water at 20.0 degrees Celsius and 750.0 torr is 32.0 mL.

Vh2o = P × V / R × T

where, P = pressure = 17.5 torr, V = volume of the water collected = 0.0 mL (not given)

Vh2o = 0.0 torr × mL / 62.36 (L•torr/K•mol) × (293.15 K) = 0.0 mL

The total volume of the gas collected, Vtotal = Vh2o + Vw + Vh2 = 0.0 mL + 32.0 mL + 0.0 mL = 32.0 mL

Now we can calculate Vw as follows: Vw = Vtotal - Vh2o = 32.0 mL - 0.0 mL = 32.0 mL

Finally, we can calculate the volume of the dry gas at STP: Vd = Vw - Vh2o

Vd = 32.0 mL - 0.9 mL ≈ 31.1 mL

Therefore, the volume of the dry gas at STP when a 32.0 mL sample of hydrogen is collected over water at 20.0 degrees Celsius and 750.0 torr is 31.1 mL.

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Answer:

The answer is D - 3.7 L.

A triglyceride that loses a fatty acid is called a diglyceride or diacylglycerol. This occurs when the triglyceride molecule undergoes a process called hydrolysis.

Hydrolysis breaks the ester bond between one of the fatty acids and the glycerol backbone, releasing a free fatty acid and forming a diglyceride.

This process is essential in the metabolism and digestion of fats in our bodies, as it allows the body to break down complex fat molecules into simpler components that can be absorbed and utilized for energy or other biological functions.

In addition, diglycerides play important roles in cell signaling and membrane structure, serving as essential building blocks for various cellular components.

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The reaction involved in the galvanic cell made from a half-cell consisting of a silver electrode in 1 M silver nitrate solution and a half-cell consisting of a zinc electrode in 1 M zinc nitrate is given as follows:2 Ag(s) + Zn2+ (aq) → Zn(s) + 2 Ag+ (aq)The standard cell potential at 25 °C for the given reaction can be determined using the following formula: E°cell

= E°cathode - E°anodeHere, the E°cathode and E°anode represent the standard reduction potentials of cathode and anode respectively. The values of these standard reduction potentials can be obtained from the standard reduction

potentials table.Using the values of standard reduction potentials from the table, we have:E°cell = E°Ag+ / Ag - E°Zn2+ / Zn= +0.80 V - (-0.76 V)= +1.56 VThe reaction is spontaneous at standard conditions because the calculated standard

cell potential is positive (+1.56 V). Therefore, the reaction will proceed spontaneously from left to right direction.The bolded non-consecutive keywords are: spontaneous, standard conditions, galvanic cell, reduction potentials.

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Answer:

We can start by finding the amount of iron used in the reaction:

Iron (Fe) is the limiting reagent since it is completely used up in the reaction.

Molar mass of Fe = 55.845 g/mol

Moles of Fe = mass / molar mass = 3.58 g / 55.845 g/mol = 0.064 moles

The balanced chemical equation for the reaction is:

4Fe + 3O2 → 2Fe2O3

From the equation, we can see that 4 moles of Fe react with 3 moles of O2 to produce 2 moles of Fe2O3.

Moles of Fe2O3 produced = mass / molar mass = 5.00 g / (2 x 159.69 g/mol) = 0.01567 moles

Since 4 moles of Fe reacts with 2 moles of Fe2O3, the theoretical yield of Fe2O3 from 0.064 moles of Fe is:

Theoretical yield of Fe2O3 = (0.064 mol Fe) x (2 mol Fe2O3 / 4 mol Fe) x (2 x 159.69 g/mol Fe2O3) = 12.746 g

The percentage purity of iron is:

Percentage purity = (actual yield / theoretical yield) x 100%

Percentage purity = (5.00 g / 12.746 g) x 100% = 39.26% (rounded to two decimal places)

Therefore, the iron wire is 39.26% pure.

The additional information necessary is: "the half-life of potassium-40." for the scientist to determine the absolute age of the fossil.

Radiometric dating is a method used to determine the absolute age of rocks and fossils based on the decay of radioactive isotopes. The rate of decay of a radioactive isotope is measured in terms of its half-life, which is the time it takes for half of the original parent atoms to decay into daughter atoms.

In this case, the scientist needs to know the half-life of potassium-40 in order to calculate the absolute age of the fossil. By knowing the half-life of potassium-40, the scientist can determine how much time has elapsed since the fossil was formed based on the proportion of parent and daughter atoms present in the fossil.

Therefore, the correct answer is: the half-life of potassium-40.

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The rate constant k for the reaction is 3.84 x 10⁻³ s⁻¹.

The second-order rate law is expressed as:

rate = k [A]²

where;

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

1/[A]t - 1/[A]0 = kt

where;

Substituting the given values into the equation, we get:

1/1.38 - 1/2.91 = k(189)

0.7246 = k(189)

k = 0.7246/189

k = 3.84 x 10⁻³ s⁻¹ (to three significant figures in scientific notation)

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