a simultaneous determination for cobalt and nickel can be based on absorption by their respective 8-hydroxyquinolinol complexes. molar absorptivities corresponding to their absorption maxima are as follows: molar absorptivity, e 365 nm co 3529 ni 3228 700 nm 428.9 10.2

Answer:

D

Explanation:

Because it has the highest number

A THE ANSWER IS A  

U WELCONM

Transverse.

Longitudinal travels in the same direction as medium.

The pH of a 0.25 M solution  \(CH_{3} COONa\) is approximately 9.26.

What is pH?

A solution's acidity or basicity (alkalinity) is determined by its pH. It is defined as the negative logarithm (base 10) of the concentration of hydrogen ions [H+] in moles per liter (M) of the solution. The pH scale ranges from 0 to 14, with 0 being the most acidic, 7 being neutral, and 14 being the most basic (also called alkaline).

To calculate the pH of the given solution \(CH_{3}COONa\),

We must think about the acetate ion's hydrolysis reaction:

\(CH_{3}COO-(aq) +H_{2}O (I)\) ⇌ \(CH_{3}COOH (aq) + OH- (aq)\)

The hydrolysis of the acetate ion, the conjugate base of acetic acid, in aqueous solution yields acetic acid and hydroxide ions.

Since  \(CH_{3}COOH\) it is a weak acid and the initial concentration  \(CH_{3}COO-\) in the solution is 0.25 M, we can assume that the amount of H+ ions generated by water dissociation is insignificant compared to the amount of OH- ions generated by the hydrolysis \(CH_{3}COO-\).

As a result, we can determine the concentration of OH- ions in the solution using the equilibrium expression for the hydrolysis of acetate ion:

Kb = \([CH_{3}COOH] [OH-]/[CH_{3}COO-]\)

Since Kb = Kw/Ka and Kw = 1.0 x \(10^{-14}\) at 25°C,

we can substitute the values for Kb and Ka to obtain the following:

1.0 x \(10^{-14}\) / 1.8 x \(10^{-5}\) = \([CH_{3}COOH][OH-]/[CH_{3}COO-]\)

[OH-] = Kb x \([CH_{3}COO-] /[CH_{3}COOH]\)

         = (1.0 x \(10^{-14}\) / 1.8 x \(10^{-5}\) ) x 0.25 / 0.25

         = 5.56 x \(10^{-10}\) M

Since the solution is not acidic, the concentration of H+ ions is equal to that of OH- ions, which have a concentration of 5.56 x \(10^{-10}\) M.

To determine the pH of the solution, we can use the following expression for the dissociation constant of water:

pH = -log[H+]

     = -log[OH-]

     = -log(5.56 x \(10^{-10}\))

     = 9.255

Therefore, the pH of a 0.25 M solution \(CH_{3}COONa\) is approximately 9.26.

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The electronic configuration for vanadium (V) in the periodic table is as follows: 1s2 2s2 2p6 3s2 3p6 4s2 3d3 (option D).

Electronic configuration is the the arrangement of electrons in an atom, molecule, or other physical structure like a crystal.

Vanadium is the 23rd element on the periodic table and has chemical symbol V with atomic number 23. It is a transition metal, used in the production of special steels.

This suggests that the electronic configuration of Vanadium will be written as follows: 1s2 2s2 2p6 3s2 3p6 4s2 3d3

Therefore, the electronic configuration for vanadium (V) in the periodic table is as follows: 1s2 2s2 2p6 3s2 3p6 4s2 3d3.

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If we increase the temperature then the more no of electrons get the energy to jump from conduction band to valence band , thereby increase the conduction of the semiconductor .

Semiconductors :

In the semiconductor the energy gap between the valence band and the conduction band is small . this small energy gap allows some electrons to move from the valence band to the conduction band . thus the semiconductor conduct electricity and conductivity increases with increase in temperature .

There are two type of semiconductor : intrinsic semiconductor and extrinsic semiconductor .

Pure semiconducting substances are called intrinsic semiconductor .

The semiconductor obtained by doping are called extrinsic semiconductors.

Extrinsic semiconductor are of two types : n-type semiconductor and     p-type semiconductor .

n-type semiconductor is due to metal excess defect and p-type semiconductor is due to metal deficiency defect .

Semiconductors are used in transistors , photo-electric devices and rectifiers .

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The vaporization of bromine will be spontaneous at temperature 298.15 K (25°C).

In order to determine the Kelvin temperature at which the vaporization of bromine, Br₂(l) → Br₂(g), will be spontaneous, we need to consider the change in Gibbs free energy (ΔG) for the process.

If ΔG is negative, the process is spontaneous at that temperature, indicating that the vaporization of bromine will occur without any external intervention. On the other hand, if ΔG is positive, the process is non-spontaneous at that temperature and will not occur without the input of energy.

The equation for ΔG is given by;

ΔG = ΔH - TΔS

where ΔH is the enthalpy change and ΔS is the entropy change for the vaporization process, and T is the temperature in Kelvin.

The values for ΔH and ΔS for the vaporization of bromine at 25°C (298.15 K) are as follows;

ΔH = 31.4 kJ/mol

ΔS = 93.1 J/(mol·K)

Substituting these values into equation ΔG;

ΔG = 31.4 kJ/mol - 298.15 K × (93.1 J/(mol·K)/1000 J/kJ) = 31.4 kJ/mol - 0.0277 kJ/mol

ΔG = 31.4 kJ/mol - 0.0277 kJ/mol = 31.3723 kJ/mol

Since ΔG is negative, the vaporization of bromine will be spontaneous at any temperature above 298.15 K (25°C).

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Skeletal muscle was the Effector in the reaction time test and motor response reflects the muscular component of reaction time.

The Effector in the reaction time test was the skeletal muscle in the finger which is used to press the button. muscle and glands produces a specific response to a stimuli's and the motor response was reaction time test is the time between electromyographic activity and movement and the motor response is the response which reflects the skeletal muscle component of reaction time.

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Answer:

0.142

Explanation:

Answer:

0.142 moles.

You would have to convert the algorithm to a broken down version of the compound.

NH4NO3(aq] → NH+4(aq] + NO−3(aq]

The ammonium is removed for this case, concentration gets broken down to zero.

So here, if 1 liter is equal to 10 x 10 x 10 milliliters...

use the formula of n and c to help you figure out the moles.

C is equal to N divided by V, so in that case...

N equals C times V.

C times V is 0.425, or 17 over 40 in simplest form.

From there, multiply 17 over 40 by the current moles, cross out the liters, and multiply by 335, then, 10 to the power of -3. You have to flip it to negative, because it will cancel out either way. Change the equation by the liters, and you have 0.125

Hence, your correct answer is 0.125

That oil sands executive is greedy and heartless and therefore can't be trusted when she claims is Ad hominem attack. So, Option B is correct.

4-  The argument in question 4 is an example of an ad hominem attack. This is due to the argument's focus on the character of the oil sands executuive rather than the actual problem, which is how to improve the company's environmental record.

The argument holds that the executive cannot be believed when she says she wants to improve the company's environmental record because she is avaricious and callous. This is an error in logic, though, as the executive's character may not necessarily be related to the company's environmental policies.

5-  The argument in question 5 is an example of an appeal to ignorance. This is because the argument states that there is no proof that humans are causing climate change, so it must be natural causes. Just because there is no conclusive proof that humans are causing climate change, it does not mean that they are not.

The argument assumes that just because there is no evidence to the contrary, the argument must be true. This is a logical fallacy.

So, Option B is correct.

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A Hertzsprung-Russell (H-R) diagram shows the relationship between a star's luminosity (brightness) and its surface temperature.

(1) Luminosity: The entire amount of energy released by a star over the course of one unit of time is known as its luminosity. It is frequently compared to a star's brightness but takes into consideration how far away the star is from Earth. Solar luminosities are commonly used to quantify brightness, with our Sun's energy output being one solar luminosity. Brighter stars are often found closer to the top of an H-R diagram while fainter stars are typically found closer to the bottom.

(2) Surface temperature: The heat or energy emitted from a star's outer layers is measured by its surface temperature. It is frequently categorized by the spectral type of the star, which is established by the absorption lines in the star's spectrum. Classes O, B, A, F, G, K, and M (from hottest to coolest) make up the categorization system for spectral types, which span from hot to cold. The horizontal axis of an H-R diagram is often used to depict the surface temperature or spectral type, with the hottest stars on the left and the coldest stars on the right.

By examining the distribution and properties of stars on the H-R diagram, astronomers can gain insights into stellar evolution, classify stars, determine their life stages, and make predictions about their future evolution. Therefore, a Hertzsprung-Russell (H-R) diagram shows the relationship between a star's luminosity (brightness) and its surface temperature.

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The atomic number of this atom is 3.

Atomic Number =Number of Protons .

Here protons=3, Neutrons=4 and Electrons=3. So, The atomic number of this atom is 3.

The charge number of an atomic nucleus is the chemical element's atomic number, also known as nuclear charge number (symbol Z). This is equivalent to the proton number (np), or the number of protons present in the nucleus of each atom of that element, for conventional nuclei.

Ordinary chemical elements can be uniquely identified by their atomic number. The atomic number and the number of electrons are both equal in a regular, uncharged atom.

The atomic mass number A of a regular atom is calculated by adding its neutron number N and neutron number Z. Since the mass of electrons is negligible for many uses, protons and neutrons have roughly equal masses, thus the mass defect of a nucleon.

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Answer:

18.52g

Explanation:

(relative atomic masses: H = 1.01, O = 16.00, Ca = 40.08)

Equation (balanced):

Ca + 2H2O -> Ca(OH)2 +H2

First, calculate the number of moles of 10g calcium

No. of moles of Ca  = 10/40.08 = 0.25 mol

Then, calculate the  number of moles of 20g water

No of moles of H2O = 1.11 mol

According to the balanced equation, 1 mole of calcium reacts with 2 moles of H2O completely.  Therefore, H2O is in excess.

So, 1 mole of calcium reacts with water to form 1 mole of Ca(OH)2 (according to the mole ratio shown in the balanced equation)

Therefore, 0.25 mol of Ca(OH)2 is produced.

Mass of Ca(OH)2 produced = no. of moles x molar mass = 0.25 x (40.08 + 16 + 16 + 1.01 + 1.01) = 18.52g

Good luck!

Option (A) is correct. LiOH is the most likely strong base added to the container containing a mixture of 0.02g g and 30ml of water.

A base is said to be a strong base if that can remove a proton (H+) from  a molecule of even a very weak acid such as water in an acid–base reaction. Some examples of strong bases are hydroxides of alkali metals and alkaline earth metals like sodium hydroxide and Ca(OH). A strong base is defined as a base that is completely dissociated in an aqueous solution. The strong bases ionizes in water to yield one or more hydroxide ion (OH-) per molecule of base. Basically strong base is a compound that has an ability to remove a proton from a very weak acid. It can completely dissociate into its ions when in water.

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Complete question is,

A scientist mixes 0.02 g of a strong base in 83 ml of water and obtains a pH of 12. he then realizes that he forgot to label the container and forgot what base he added. what is the most likely the identity of this base?

A. LiOH

B. NaOH

C. RbOH

D. KOH

Answer:

gonna check them rn :) youre not d u mb dont worry (:

The correct order of the given elements above in their increasing atomic radii are as follows:

The atomic radius of an element is one periodic properties of elements which describes the total distance between the center of the nucleus of an element to the outermost shell of an electron.

From the task given above, the atomic radii values of the elements in the problem above are: Phosphorus ( 98pm ), Cobalt ( 152pm ), Ruthenium ( 178pm ), Osmium ( 185pm ) and finally Gallium which is 187pm.

That being said, below are some few examples of periodicities which is seen in elements in the periodic table:

In conclusion, the atomic radius and atomic size are both periodic properties of elements.

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Answer:

368.92g

Explanation:

Firstly, let's balance the equation which is

2NO + O₂ ---> 2NO₂

Starting with 8.02 mol of NO let's calculate the moles of oxygen which is in a 2 : 1 molar ratio

2NO + O₂

2 : 1

8.02 mol : x mol

Moles of O₂ = 8.02 ÷ 2 = 4.01 mol

Doing the same thing for 18.75 mol of O₂ to calculate the number of moles of NO

2NO + O₂

2 : 1

x mol : 18.75 mol

Moles of NO = 18.75 × 2 = 37.5 however we are told we have 8.02 moles of NO, so we are unable to use 18.75 mol of O₂

Using 8.02 mol of NO to figure out the number of moles of NO₂ :

2NO : 2NO₂

They have the same molar ratio of 2 : 2, so the number of moles is 8.02

Using formula moles = mass / Molar mass

Rearranging to find mass = moles × molar mass

Molar mass of NO₂ = 14 + 16 + 16 = 46

Mass = 46 × 8.02 = 368.92g

Reaction:

2NO + O₂ → 2NO₂

determine the limiting reactant from the ratio of moles to the reaction coefficient

NO : O₂ = 8.02/2 : 18.75/1 = 4.01 : 18.75

NO as a limiting reactant (smaller ratio)

so mole NO₂ from limiting reactant (NO) :

= 2/2 x mole NO

= 2/2 x 8.02

= 8.02

mass NO₂ = mole x molar mass NO₂ = 8.02 x 46 g/mole = 368.92 g

The capacity of an element in a chemical bond to draw the common electron pair is measured by electronegativity, which is a relative variable (s).

The propensity of an atom to draw electrons (or electronic structure) to itself is measured by its electronegativity. It regulates the flow of the shared electrons of the two molecules in a link. The larger an asteroid's electronegativity, the further aggressively it will draw electrons from its bonds.

The capacity of an atoms to draw electron density in a covalent connection is referred to as electronegativity. The stronger a material pulls the shared electrons, the greater its degree of electronegativity.

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Answer:

Explanation:

if you are wondering how you say that, you say "why the cat sits on the stove" but if it's a random question that has no sense to it my answer to you would be the cat needs some love and heat, the stove is the hottest thing it has right now. Give it some love!

To reach break point chlorination in a 96,000 gallon pool with a difference of 0.4 ppm between the free chlorine and total chlorine levels, approximately 7.68 ounces of chlorine is needed.

To calculate the amount of chlorine needed to reach break point chlorination in a 96,000 gallon pool, we first need to find the difference between the total chlorine and free chlorine levels. Break point chlorination is achieved when the free chlorine level equals the total chlorine level.

Given that the free chlorine level is 1.4 ppm and the total chlorine level is 1.8 ppm, the difference between them is:

1.8 ppm - 1.4 ppm = 0.4 ppm

Now, we need to determine the amount of chlorine required to raise the free chlorine level by 0.4 ppm in a 10,000 gallon pool. The given information states that it takes 2 ounces of dry chlorine (67% concentration) to raise a 10,000 gallon pool's chlorine level by 1 ppm.

To calculate the amount of chlorine required to raise the free chlorine level by 0.4 ppm in a 10,000 gallon pool, we can set up a proportion:

2 ounces / 1 ppm = X ounces / 0.4 ppm

Solving for X (the amount of chlorine needed for 0.4 ppm increase in a 10,000 gallon pool):

X = (2 ounces / 1 ppm) * 0.4 ppm = 0.8 ounces

Now, we can calculate the amount of chlorine needed for the 96,000 gallon pool by scaling the chlorine required for the 10,000 gallon pool:

Amount of chlorine needed = (0.8 ounces / 10,000 gallons) * 96,000 gallons

Amount of chlorine needed = 0.8 ounces * 9.6 = 7.68 ounces

Therefore, approximately 7.68 ounces of chlorine is needed to reach break point chlorination in the 96,000 gallon pool.

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Answer:

C + 2H2 ⇒ CH4

Explanation:

In order to balance a chemical equation you need to make sure that the number of atoms on both sides are equal

C + H2 = CH4

C = 1

H = 2

Products:

C = 1

H = 4

H2 = 2 × 2 = 4

C + 2H2 ⇒ CH4

Hope this helps.

Answer:

Yes

Explanation:

By definition, the equilibrium constanct, Kc, for the reaction A ⇒ 2B is

= [A]^1 / [B]^2

Substitute [A] = 4 and [B] = 2 in the equation,

[A]^1 / [B]^2

= 4^1 / 2^2

= 1

= Kc

So yes the reaction is at equilibrium.

Let's find K_c

\(\\ \rm\Rrightarrow K_c=\dfrac{[B^]^2}{[A]^1}\)

\(\\ \rm\Rrightarrow 1=\dfrac{2^2}{4}\)

\(\\ \rm\Rrightarrow 1=\dfrac{4}{4}\)

\(\\ \rm\Rrightarrow 1=1\)

Yes it's at equilibrium

Answer:

Most plastic is chemically inert and will not react chemically with other substances -- you can store alcohol, soap, water, acid or gasoline in a plastic container without dissolving the container itself.

Explanation:

Answer:

Most plastic is chemically inert and will not react chemically with other substances -- you can store alcohol, soap, water, acid or gasoline in a plastic container without dissolving the container itself.

Explanation:

Hope it helps u

FOLLOW MY ACCOUNT PLS PLS

Answer:

C

Explanation:

Because NH3 has 8 valence electrons, and Hydrogen can only have 1 bond

Answer:

153.3 grams of ZrCl₄ are produced

Explanation:

The equation of the reaction is as follows:

ZrSiO₄ + Cl₂ ----> ZrCl₄ + SiO₂ + O₂

molar mass of ZrSiO₄ = (91 + 32 + 16 * 4) = 187.0 g/mol

molar mass of ZrCl₄ = (91 + 35.5 * 4) = 233.0 g/mol

molar mass of Cl₂ = (35.5 * 2) 71.0 g/mol

From the equation of reaction, 1 mole of ZrSiO₄ reacts with one mole of  Cl₂ to produce one mole of ZrCl₄

number of moles of ZrSiO₄ present in 123 g = 123/187 = 0.65 moles

number of moles of Cl₂ present in 85.0 g = 85.0/71.0 = 1.19 moles

therefore, ZrSiO₄ is the limiting reactant

123.0 g of ZrSiO₄ will react with excess Cl₂ to produce 123 * 233/187 grams of ZrCl₄ = 153.3 grams of ZrCl₄

Therefore, 153.3 grams of ZrCl₄ are produced

Ferrihydrite in forest soil at pH=5 is more likely to sorb benzene than 2,4-D. At pH=4, the sorption potential of 2,4-D to ferrihydrite may be enhanced due to increased positive charge on the surface of the hydroxide.

Ferrihydrite, a type of iron oxide, has the ability to sorb organic compounds through various mechanisms such as surface complexation, hydrogen bonding, and hydrophobic interactions. Benzene, being a non-polar compound, is more likely to sorb to ferrihydrite due to hydrophobic interactions and weak van der Waals forces. On the other hand, 2,4-D, being a polar compound, may have limited sorption to ferrihydrite at pH=5 due to the dominance of repulsive interactions between the negatively charged surface of ferrihydrite and the negatively charged 2,4-D molecule.

At pH=4, the increased positive charge on the surface of ferrihydrite enhances the sorption potential of 2,4-D. The positive charge can attract and bind with the negatively charged 2,4-D molecule through electrostatic interactions. This can result in increased sorption of 2,4-D to ferrihydrite in tropical soils like Qxisol.

Conversely, at pH=9, the increased pH results in a decrease in the positive charge on the surface of ferrihydrite. This reduction in positive charge limits the sorption potential of 2,4-D as the electrostatic attraction between the hydroxide and the 2,4-D molecule decreases. This suggests that in arid soils like Aridisol, characterized by higher pH levels, the sorption potential of 2,4-D to ferrihydrite may be lower compared to humid climates.

The sorption potential of 2,4-D as a function of soil type in humid vs. arid climates can be predicted by considering the pH of the soil. Higher pH in arid soils can lead to reduced sorption of 2,4-D to hydroxides like ferrihydrite or goethite, while lower pH in humid soils can enhance the sorption potential due to increased positive charge on the hydroxide surface.

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The molar masses of Mg and Fe are:

Magnesium oxide:

Mass of oxygen = 1

Mass of magnesium = 1.5

Molar mass of magnesium = (1.5 / 1) × 16 = 24

Iron oxide:

Mass of oxygen = 1

Mass of iron = 3.5

Molar mass of iron = (3.5 / 1) × 16 = 52

The accepted molar masses of Mg and Fe are 24.305 g/mol and 55.845 g/mol, respectively. The values I obtained are slightly different from the accepted values, but the difference is within experimental error.

There are a few possible reasons for the differences between the values obtained and the accepted values. One possibility is that the compounds used were not pure. Another possibility is that an error was made in calculations. Finally, it is also possible that the accepted values are not accurate.

To account for the differences, repeat the experiment with more accurate measurements and a purer sample of the compounds. Also check the accepted values to make sure they are accurate.

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Answer:

A strong alkali is 100% ionised.eg÷sodium hydroxide.

A week alkali is not 100% ionised.eg÷ammonia

A concentrated acid contains a large amount of acid in a given volume.

Answer-1:

A strong alkali dissociates completely to form OH- ions. A weak alkali only partially dissociates to form OH- ions. An example of a strong alkali is is sodium hydroxide.

Answer-2

If the number of certain moles in per litre of a molecule is more then the acidic substance is known as concentrated acid. For example : In dilute solution of H2SO4 the concentration of acid is 2% and 98% water.

The identity of the metal is copper.

The amount of energy needed to raise the temperature of one gram of a substance by one degree Celsius.

Using the formula of specific heat

H = mcdT

Where, H = Heat absorbed

m = mass of the metal

c = specific heat capacity of the metal

dT = temperature change

Putting the values in the equation

20 J = 0.0052 Kg × c × ( 40.0°C - 30.0°C)

c = 20 J/0.0052 Kg × ( 40.0°C - 30.0°C)

c = 385 JKg-1°C-1

Thus, the metal is copper.

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The first step in solving this problem is to write out the balanced chemical equation for the reaction between methane (CH4) and oxygen (O2):

CH4 + 2O2 → CO2 + 2H2O

Next, we need to determine which reactant is the limiting reagent. To do this, we can use the mole ratios from the balanced equation and compare them to the given amounts of each reactant:

For methane: 1.35 mol CH4 × (2 mol O2 / 1 mol CH4) = 2.70 mol O2 required
For oxygen: 3.41 mol O2

Since we have more than enough oxygen to react with the amount of methane given, oxygen is not the limiting reagent. Therefore, we will use the amount of methane (1.35 mol) to calculate the amount of products produced:

1.35 mol CH4 × (1 mol CO2 / 1 mol CH4) × (8.31 kJ/mol) = 11.2 kJ

Therefore, the amount of energy produced from the reaction of 1.35 moles of methane with 3.41 moles of oxygen is 11.2 kJ.


To calculate the amount of energy produced in kilojoules, we can use the same equation as before but with the new amount of methane required (2.70 mol):

2.70 mol CH4 × (1 mol CO2 / 1 mol CH4) × (8.31 kJ/mol) = 22.8 kJ

Therefore, the amount of energy produced from the reaction of 2.70 moles of methane with 3.41 moles of oxygen is 22.8 kJ.

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Answer:

We round numbers so we can find an answer or an estimate that will be close to the actual answer. Rounding numbers is also another way to get close to an exact answer without the trouble of having to calculate every number.

Answer:

Rounding numbers make the numbers easier and more simple to use . Though they may less accurate because of the changes number . Rounding is mainly used for estimates