why are ionic solids brittle

Answer:

PLEASE MARK ME AS THE BRAINLIEST

Explanation:

According to the 2n2 rule, the maximum number of electrons in the third period = 2 x (3)2 = 18. But, the last shell cannot accommodate more than 8 electrons so, the number of electrons in third period is 8. Hence, the number of elements is also 8.

\(13.86 seconds\)  required for 65% of the initial quantity of reactant to be consumed

A first order reaction's rate constant is provided by:

rate = k[A]

A reactant is a substance that participates in a chemical reaction and is changed into a product.

where [A] is the concentration of the reactant.

In this case, the rate constant is given as 0.0450 s-1.

To calculate the time required for 65% of the initial quantity of reactant to be consumed, we can use the following equation:

\(t = (\frac{1}{k})[ln(1 - 0.65)]\)

Substituting the values, we get:

\(t = (\frac{1}{0.0450 s^{-1}})[ln(1 - 0.65)] \\\\t= 13.86 s\)

Therefore, it will take \(13.86 seconds\) for 65% of the reactant's original volume to be consumed.

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Answer:

more

Explanation:

seems like you did not finish the questions

The Wilke-Chang method is used to predict the diffusion coefficient of Phosphoric acid in water. The Wilke-Chang method is a widely used empirical equation to estimate the diffusion coefficient of a solute in a solvent.

Fick's Law of diffusion states that the mass transfer rate of a solute across a porous membrane is proportional to the concentration gradient and the diffusion coefficient.

a. It takes into account the molecular weight, viscosity, and density of the solute and solvent. By plugging in the relevant values for Phosphoric acid and water, we can calculate the diffusion coefficient.

To calculate the diffusion coefficient of Phosphoric acid in water using the Wilke-Chang method, we need to know the molecular weight of Phosphoric acid (H3PO4) and water. The molecular weight of H3PO4 is 98 g/mol, and the molecular weight of water is 18 g/mol.

The Wilke-Chang equation is given by:

D = (1 / Φ) * [(1/M1 + 1/M2) / (√(1/μ1) + √(1/μ2))] * (T / P)

where D is the diffusion coefficient, Φ is the void fraction of the ceramic filter, M1 and M2 are the molecular weights of the solute and solvent, μ1 and μ2 are the viscosities of the solute and solvent, and T is the temperature in Kelvin.

b. We have the mass transfer rate and the thickness of the ceramic filter, so by rearranging Fick's Law equation, we can calculate the concentration at the other side of the filter.

The equation is given by:

J = -D * ∆C/∆x

where J is the mass transfer rate, D is the diffusion coefficient, ∆C is the change in concentration, and ∆x is the thickness of the ceramic filter.

We have the mass transfer rate (1.4 x 10^(-9) kg mol H3PO4/s.m²) and the thickness of the ceramic filter (4.2 mm = 0.0042 m), so by rearranging the equation, we can calculate the change in concentration (∆C) and then use it to find the concentration at the other side of the ceramic filter.

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70 g of a solid solute is added to 50 g of water at 20 °c, and it all dissolves. when additional solute is added, it does not dissolve. KI is the solute.

What is solute ?

A solute is a substance that has dissolved in a solution. Molecules of the solvent often outnumber those of the solute in a fluid solution. In our daily lives, salt and water are two of the most prevalent solutes. Salt becomes a solute when it is dissolved in water.

What is solvent?

Solvents are employed to dissolve the substances that serve as the formulation's solutes. The components of these solutes can be solids, liquids, or gases. The use of a suitable solvent in conjunction with the solute is required to create a solution.

given: 70g of solute is added to 50g of water at 20degree C

solution: at 20degree C,

since graph is for 100g of water

multiple by 2

2 x 50g of water=100g of water

similarly 2 x 70g of solute= 140g of solute

at 20degree C, The solute KI falls at 140g

Therefore , KI is the solute

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The value of b if the average rate of change of q(t) between t = 0 and t = b is 1.25 is 4.

To find b, we need to use the formula for average rate of change:

average rate of change = (q(b) - q(0)) / (b - 0) = 1.25

Simplifying this equation, we get:

q(b) - q(0) = 1.25b

We don't know what q(b) is, but we can use the information given to find q(0). Since the problem doesn't give us an actual function q(t), we can assume that q(t) is a linear function. This means that the rate of change is constant, and we can use the slope of the line to find the rate of change.

The average rate of change of q(t) between t=0 and t=b is 1.25, which means that the slope of the line connecting (0,q(0)) and (b,q(b)) is 1.25.

Using the slope formula, we get:

slope = (q(b) - q(0)) / (b - 0) = 1.25

Simplifying this equation, we get:

q(b) - q(0) = 1.25b

But we already have this equation from before! So we can substitute 1.25b for q(b) - q(0):

1.25b = q(b) - q(0)

Now we just need to solve for b. Rearranging the equation, we get:

q(b) = 1.25b + q(0)

Since we don't know what q(0) is, we can't solve for b exactly. However, we do know that q(b) is the value of q(t) at time t = b, so we can make an educated guess. Let's assume that q(0) = 0 (meaning there were no widgets at time t=0), then we get:

q(b) = 1.25b + 0

q(b) = 1.25b

This means that the value of q(b) is 1.25 times the value of b. So if we want the average rate of change to be 1.25, we need to find a value of b such that q(b) is 1.25 times b.

For example, if we plug in b=4, we get:

q(4) = 1.25(4) = 5

This means that the value of q at time t=4 is 5. So if q(t) is a linear function with a slope of 1.25, then q(0) = 0 and q(4) = 5, and the line connecting these two points has an average rate of change of 1.25 between t=0 and t=4.

Therefore, b = 4 is one possible answer to the problem.

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Answer:

Ver explicación abajo

Explanation:

LA pregunta esta incompleta, pero logré conseguir un ejercicio muy parecido a este con datos similares, y la pregunta que falta como tal son estas:

"a) La cantidad de sal producida.

b)  Moléculas de hidrógeno obtenidas a 25 ºC y 740 mm Hg.

c)  El volumen de la disolución de ácido necesario para la reacción."

Asumiendo que estos son los datos faltantes, hay que ver como resolver por parte:

a) Cantidad de sal producida.

En este caso debemos plantear la reacción que se lleva a cabo. Es un mineral que tiene Zinc y reacciona con acido sulfurico, por tanto la reacción que se lleva a cabo en teoría es:

Zn + H₂SO₄ -----------> ZnSO₄ + H₂

Entonces, queremos saber la cantidad de ZnSO₄ que se formó.

Para eso, debemos calcular primero cuantos gramos de zinc hay originalmente en la muestra, que son los que reaccionaron para formar esta sal, y luego los moles para que por medio de estequiometría, calculemos los moles de la sal.

Para la masa de Zinc, sabemos que el mineral contiene 65% de zinc o 0,65 entonces:

mZn = 0,65 * 500 = 325 g

Calculamos los moles usando la masa molecular de Zinc que es 65,37 g/mol:

moles = 325 / 65,37 = 4.97 moles

Ahora bien, como la reacción de arriba está bien balanceada, podemos asuimr por estequiometría que la relación Zn / ZnSO₄ es 1:1, asi que los moles de Zn serán los mismos de la sal por tanto:

moles Zn = moles ZnSO₄ = 4,97 moles

Calculando la masa molecular de ZnSO₄:

MM ZnSO₄ = 65,37 + 32 + (16 * 4) = 161,37 g/mol

Finalmente la masa de la sal es:

m ZnSO₄ = 4,97 * 161,37

b) Moléculas de hidrógeno obtenidas

PAra este caso, ya tenemos los moles de Zn, y por estequiometría, todas las especies presentes están en relación 1:1, así que los moles de hidrógeno son los mismos de zinc. No es necesario el dato de temperatura y presión acá pues ya tenemos los moles.

Para conocer el número de moléculas, necesitamos el número de abogadro que es 6.02x10²³ por lo tanto las moléculas de hidrógeno:

Moléculas de hidrógeno = 6,02x10²³ * 4,97

c) Volúmen de ácido empleado

Finalmente para el ácido, como ya conocemos los moles empleados, podemos calcular la masa del ácido usando su peso molecular:

MM H₂SO₄ = (2*1) + 32 + (4*16) = 98 g/mol

m H₂SO₄ = 4,97 * 98 = 487,06 g

Ahora que ya sabemos su masa, solo calculamos la masa realmente usada (pues su %p/p es 96%) y con la densidad calculamos el volumen:

d = m/v

v = m/d

m H₂SO₄ (puro) = 487,96 * 0,96 = 467,58 g

El volumen será:

V = 467,58 g / 1,823

Espero que esto te sirva, o te ayude como impulso a tu ejercicio real.

Answer:

Aboitic factor would be soil

Biotic factor would be ants.

Explanation:

The mass of the compound required in the given number of moles is 70.38 g.

The given parameters;

The mass of the compound that will be required in the number of moles is the product of the molecular weight of the compound and its number of moles available.

The mass of the compound required in the given number of moles is calculated as follows;

mass = moles x molecular weight

mass = 0.51 x 138

mass = 70.38 g

Thus, the mass of the compound required in the given number of moles is 70.38 g.

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Fluoride supplements are often recommended for children who do not receive enough fluoride through their diet and drinking water. The American Dental Association recommends fluoride supplements for children who are at high risk of developing cavities and who live in areas where the fluoride level in drinking water is low.

For children under 3 years old, the recommended fluoride supplement is usually a liquid supplement that contains 0.25 milligrams of fluoride per day. This supplement is typically prescribed by a pediatrician or dentist.

For children between 3 and 6 years old, the recommended fluoride supplement dosage varies based on the child's weight. Generally, the dosage is 0.5 milligrams of fluoride per day for every 10 pounds of body weight. For example, a child who weighs 30 pounds would need 1.5 milligrams of fluoride per day.

It is important to note that fluoride supplements should only be given under the guidance of a healthcare professional. Overdosing on fluoride can lead to fluorosis, a condition that causes discoloration and pitting of the teeth.

In addition to fluoride supplements, children can also receive fluoride through fluoride varnish treatments at the dentist, fluoride toothpaste, and fluoridated drinking water. It is important to speak with a healthcare professional to determine the best way to ensure your child is receiving adequate fluoride for their dental health.

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Gravity, as a fundamental force of nature, is influenced by several factors. The following are some of the key factors affecting gravity:

The two electrons does the NAD transport. Due to the chemical structure, each of the molecule of NAD+ can accept the two electrons.

The one role of the NAD+ is that to initiate the electron transport chain through the reaction with the organic metabolite that is the intermediate in the metabolic reactions. This is called as the oxidation reaction in which the 2 hydrogen atoms or the 2 hydrogen ions and the 2 electrons will be removed from the organic metabolite.

In the each of the enzymatic reactions, the NAD+ will accepts the two electrons and the H+ from the ethanol to form the NADH.

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Answer:

d.

Explanation:

Answer:

D!

Explanation:

A is not true! When big meteors fall into the ocean, they cause mega-tsunamis I think, which does a lot of damage.

B, no, Uranus does too.

C, I think this is untrue, red wavelength and reflects the blue the blue!

D, is so true! A lot of reliable sources on this one!

Sorry if I did any wrong, I haven't learn chemistry in school yet.

N and P pairs of elements would you expect to form a polar covalent bond.

A covalent bond is formed when two atoms exchange one or more pairs of electrons. The two nucleus are concurrently drawing these electrons to them. When the difference between both the electronegativity values of two atoms is too tiny for a transfer of electrons to actually occur to create ions, a covalent bond is formed.

Covalent bonds between atoms in a Lewis structure are shown as a single line connecting the two atoms, which corresponds to the chemical symbol for the element. Diatomic molecules including hydrogen, nitrogen, fluorine, chlorine, bromine, iodine, and astatine are the principal sources of covalent bonding.

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Answer:

if an object weighs more than an equal volume of water, it is more dense and will sink, and if it weighs less than an equal volume of water, it is less dense and will float.

Explanation:

Hope that helps

As a result, the protein molecule is 315 x 10^-9 metres long.

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Answer:

For example, the atomic radius of the metal zirconium, Zr, (a period-5 transition element) is 155 pm (empirical value) and that of hafnium, Hf, (the corresponding period-6 element) is 159 pm. ... The increase in mass and the unchanged radii lead to a steep increase in density from 6.51 to 13.35 g/cm3.

Explanation:

Answer:

P2 = 2.25 atm

Explanation:

Given:

V1 = 1.5 L. V2 = 2.0 L

P1 = 3.0 atm. P2 = ?

Use Boyle's law and solve for P2:

P1V1 = P2V2

or

P2 = (V1/V2)P1

= (1.5 L/2.0L)(3.0 atm)

= 2.25 atm

Explanation:

Difference between 63 and 65 = 2.

(63.55 - 63) / 2 * 100% = 27.5%.

(65 - 63.55) / 2 * 100% = 72.5%.

Hence there is 72.5% of the isotope with atomic mass 63 and 27.5% of the isotope with atomic mass 65 in copper.

sunscreen with a protection factor of over 15, wear protective clothing that covers targeted areas of the skin, or just stay inside.

sunglasses also help prevent uv rays from damaging your eyes. it's also important to wear a hat since your head is directly in the way of the sun.

hope this helps!

This law states that matter can neither be created nor destroyed in an ordinary chemical reaction, but can change from one form to another.

What this implies is that when two elements or compound combine as a reactant to form a product, there's no loss of matter and the mass of the reactants must be equal to the mass of the product.

Given that

AlBr₃ + K₂SO₄ → KBr + Al₂(SO₄)₃

If we look closely at the above reaction, we would see that aluminuim is not balanced, potassium is also not balanced, bromine is not balance as well as sulphur and oxygen.

Let's put two moles attached to the AlBr₂ and three moles of K₂SO₄

2AlBr₃ + 3K₂SO₄ →

This would give us

6KBr + Al₂(SO₄)₃

If we add the two equations together,

2AlBr₃ + 3K₂SO₄ → 6KBr + Al₂(SO₄)₃

From the above, we have

2 atoms of Al on the reactant side and 2 atoms of Al on the product side

6 atoms of Br on the reactant side and 6 atoms of Br on the product side

6 atoms of K on the reactant side and 6 atoms of K on the product side

3 atoms of S on the reactant side and 3 atoms of S on the product side

12 atoms of O on the reactant side and 12 atoms of O on the product side

The boiling of pure water has been resulted in the particles gaining energy and moving away from each other. Thus, option A is correct.

The boiling can be described as the conversion of the liquid state to the gaseous state. The molecules in the gaseous space are apart from each other and have no fixed shape.

The pure water has been transferred to the gaseous state at the temperature of 100 degrees celsius. The boiling has been introduced with the addition of the energy.

The water molecules gain energy and start to vibrate. The vibrations have resulted in the change in the change in phase of the liquid with evaporation.

Thus, when pure water boils, the water particles gain energy and move away from each other. Thus option A is correct.

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Answer:

1. 2.63x10^6

2. 39.2

Both answers have been rounded

Answer: Molarity of the solution: 0.12

Molarity of sulfate ion: 0.360

Molarity of aluminum ion: 0.240

Explanation:

I’m not sure if that’s what you’re looking for

Answer:

In order to find the two statements, we must first define what the enthalpy of formation and the enthalpy of reaction mean.

Enthalpy of formation:

The change in enthalpy when one mole of substance is formed from its constituent elemetns at standard state.

Enthalpy of reaction:

The change in enthalpy when a reaction occurs and the reactants and products are in their standard states.

Now, we check the statements. The true ones are:

The Hrxn for C(s) + O₂(g) → CO₂(g) is the same as Hf for CO₂

This is true because the formation of carbon dioxide requires carbon and oxygen in their standard states.

The Hf for Br₂(l) is 0 kJ/mol by definition.

Because the bromine is present in its standard state, the enthalpy of formation is 0.

The Hrxn for the reaction 1.5H₂(g) + 0.5N₂(g) → NH₃(g) is the same as the Hf for NH₃(g)

The reactants and products are present in their standard state, and the reaction is the same as the one occurring during the formation of ammonia.

Answer:

1) oxidation

2) Reduction

3) Oxidation

4) Reduction

5) Reduction

6) Reduction

7) Oxidation

8) Reduction

Explanation:

Oxidation is said to have taken place when there is a positive change in the oxidation number while reduction is said to have taken place when there is a decrease in the oxidation number.

The change from CH3CHO to CH3CH2OH represents on oxidation reaction.

The change from CH3OH to CH4 is a reduction because the oxidation number of carbon changes from +2 to -4.

The change from N2H4to N2 is an oxidation because the oxidation number of nitrogen increases from -2 to 0.

The gain in electrons is a reduction because the gain of electron leads to a decrease in oxidation number.

The change from NO- 2 to NH3 is a reduction because the oxidation number of nitrogen changes from +4 to -3.

The change from NAD+ to NADH is a reduction since NAD+ is the oxidized form of the enzyme while NADH is the reduced form of the enzyme.

The change from CH4 to Co2 is an oxidation because the oxidation number of carbon changes from -4 to + 4.

The change from Ag+ to Ag is a reduction because it involves the gain of one electron and a consequent decrease in oxidation number.

The balanced nuclear equation for the nuclear fission of 235U into 92Kr and 141Ba can be written as follows:

235U + 1n → 92Kr + 141Ba + 2(1n)

In this equation, a neutron (1n) collides with a uranium-235 (235U) nucleus, resulting in the fission of the uranium nucleus. The fission products are krypton-92 (92Kr) and barium-141 (141Ba), along with the release of two additional neutrons. It is important to note that the equation represents a simplified representation of nuclear fission, and the actual process involves a complex series of reactions and the release of additional particles and energy.

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