Estimate the optimal number of neutrons for a nucleus containing 70 protons.

Answers

Answer 1

Atomic number 70

weight 173

number of neutron = weight - Atomic number

= 173 -70

=103

Answer 2

The optimal number of neutrons for a nucleus containing 70 protons is 130

Further explanation

In chemistry, the nucleus is the positively charged center of the atom that consist of protons and neutrons. It's also known as the "atomic nucleus"

The neutron is a subatomic particle with no net electric charge and a mass slightly greater than that of a proton. The neutron is have symbol n or n⁰. Protons and neutrons constitute the nuclei of atoms.

Neutron is a type of atomic particle which does not possess any kind of charge on it. It has neutral behavior toward atoms since it does not possess any kind of charges but it contributes to the mass of the atoms.

Atomic number = 70

Atomic weight = 173

Atomic weight = number of protons + number of neutrons

Atomic number = number of protons

Therefore, the number of protons = 70

Number of neutrons = atomic weight - number of protons

Number of neutrons = 173 - 70 = 103

Optimal number of neutrons = 130

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Answer details

Grade:  9

Subject:  chemistry

Chapter:  the optimal number of neutrons

Keywords: protons, nucleus, neutrons

Estimate The Optimal Number Of Neutrons For A Nucleus Containing 70 Protons.

Related Questions

the pressure of a sample of helium in a 0.2 L container is 2.0atm. if the helium is compressed to a volume of 10.0 ml ,what would be the pressure of the gas?

Answers

Answer:

The pressure of the gas is 40atm

Explanation:

Given parameters:

P₁ = 2.0atm

V₁ = 0.2L

V₂ = 10.0mL = 10 x10⁻³L = 0.01L

P₂ =?

We apply Boyle's law to solve this kind of problem

Boyle's law states that "the volume of a fixed mass of a gas varies inversely as the pressure changes if the temperature is constant".

It is expressed as P₁V₁ = P₂V₂

Making P₂ the subject of the formula gives:

P₂ = P₁V₁/V₂

Inserting the values of the parameters:

P₂ = 2x0.2/0.01

P₂ = 40atm

What is the pH of a solution with a pOH of 10?

6

4

10

14

Answers

Answer:

= 4

Explanation:

The pH of a solution is given by;

pH = - log [H+] , while

pOH = - log [OH-]

But; pH + pOH = 14

Therefore;

pH = 14 - pOH

     = 14 - 10

     = 4

4 is the correct answer

If you are given a chemical equation and specific amounts for each reactant in grams, how would you determine how much product can possibly be made? if you are given a chemical equation and specific amounts for each reactant in grams, how would you determine how much product can possibly be made? 1. convert each reactant into moles of the product. 2. determine which reactant is the limiting reactant. 3. convert the moles of product, from the limiting reactant, to grams. 1. determine which reactant is the limiting reactant. 2. convert each reactant into moles of the product. 3. convert the moles of product, from the limiting reactant, to grams. 1. determine which reactant is the limiting reactant. 2. using conversion factor, convert grams of the limiting reactant to grams of the product.

Answers

1. Find the mole of each reactant present and determine the limiting reactant 2. determine the mole of product produced through the mole ratio of the equation 3. convert to grams if the 'amount' refers to grams

Oxides of nitrogen result from a combination of nitrogen and A. hydrogen. B. carbon. C. oxygen. D. argon.

Answers

When something is oxidized it means that oxygen is added to it. Therefore the answer is C. Oxygen!

Hope this helped!

Oxides of nitrogen result from a combination of nitrogen and oxygen. Hence, the correct answer is C. oxygen.

Oxides of nitrogen, commonly known as nitrogen oxides or NOx, are usually formed from a combination of nitrogen and oxygen. Specifically, they refer to compounds that basically contain nitrogen and oxygen atoms, such as nitrogen monoxide (NO), nitrogen dioxide (NO₂), and nitrogen trioxide (N₂O₃).

Generally, these oxides of nitrogen are often produced during high-temperature combustion processes, such as those occurring in vehicle engines, power plants, and industrial processes. The primary source of oxygen for the formation of nitrogen oxides is atmospheric oxygen (O₂).

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A nascar racecar can attain speeds of over 225 miles/hour on super speedways. How fast is this in km/hr

Answers

It is 362.102 km/hr

Answer:

The correct answer is [tex]362.32 \frac{km}{hour}[/tex]

Explanation:

The rule of three or is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them. That is, what is intended with it is to find the fourth term of a proportion knowing the other three. Remember that proportionality is a constant relationship or ratio between different magnitudes.

If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other, the direct rule of three must be applied. To solve a direct rule of three, the following formula must be followed:

A ⇒ B

C ⇒ x

So [tex]x=\frac{C*B}{A}[/tex]

The direct rule of three is the rule applied in this case where there is a change of units. To perform this conversion of units, you must first know that 1km = 0.621 miles. So, if 1 km is 0.621 miles, how many kilometers equals 225 miles?

[tex]x kilometers=\frac{225 miles*1 km}{0.621 miles}[/tex]

[tex]x kilometers=362.32 kilometers[/tex]

So, finally,

[tex]225 \frac{miles}{hour} =362.32 \frac{miles}{hour}[/tex]

write a balanced equation that describes the dissociation of chromium(III) nitrate in water

Answers

Final answer:

The balanced equation for the dissociation of chromium(III) nitrate in water is Cr(NO3)3 (s) → Cr3+ (aq) + 3 NO3- (aq), illustrating the separation into chromium(III) ions and nitrate ions.

Explanation:

The balanced equation that describes the dissociation of chromium(III) nitrate in water is as follows:

Cr(NO3)3 (s) → Cr3+ (aq) + 3 NO3− (aq)

When chromium(III) nitrate dissolves in water, it separates into chromium(III) ions and nitrate ions. Each formula unit of the solid compound yields one chromium(III) ion and three nitrate ions. The equation is balanced with respect to both mass and charge, fulfilling the law of conservation of mass and the principle of electroneutrality.

To describe the process, it is important to note that chromium(III) nitrate is a salt, and like most salts, it dissociates completely in water to give its constituent ions.

How many moles of compound are there in the following?
a. 6.60 g (NH4)2SO4
b. . 4.5 kg Ca(OH)2

Answers

a) (NH4)2SO4 --- 1 mole of it contains 2 moles of N, 8 moles of H, 1 mole of S, and 4 moles of O.

MM = (2 moles N x 14.0 g/mole) + (8 moles H x 1.01 g/mole) + (1 mole S x 32.1 g/mole) + (4 moles O x 16.0 g/mole) = 132 g/mole.

6.60 g (NH4)2SO4 x (1 mole (NH4)2SO4 / 132 g (NH4)2SO4) = 0.0500 moles (NH4)2SO4

b) The molar mass for Ca(OH)2 = 74.0 g/mole, calculated like (NH4)2SO4 above.

4.5 kg Ca(OH)2 x (1000 g / 1 kg) x (1 mole Ca(OH)2 / 74.0 g Ca(OH)2) = 60.8 moles Ca(OH)2

The number of mole in the compounds are:

A. 6.60 g of (NH₄)₂SO₄ contains 0.05 mole.

B. 4.5 kg Ca(OH)₂ contains 60.81 moles

The mole of a substance is related to its mass and molar mass according to the equation:

[tex]Mole = \frac{mass}{molar mass }[/tex]

With the above formula, we can obtain the answer to the questions given above. This is illustrated below:

A. Determination of the number of mole in  6.60 g of (NH₄)₂SO₄

Molar mass of (NH₄)₂SO₄ = 2[14 + (4×1)] + 32 + (4×16)

= 2[14 + 4] + 32 + 64

= 2[18] + 32 + 64

= 36 + 32 + 64

= 132 g/mol

Mass of NH₄)₂SO₄ = 6.60 g

Mole of NH₄)₂SO₄ =?

[tex]Mole = \frac{mass}{molar mass }[/tex]

Mole of NH₄)₂SO₄ = [tex]\frac{6.6}{132}\\\\\\[/tex]

Mole of NH₄)₂SO₄ = 0.05 mole

Thus, 6.60 g of (NH₄)₂SO₄ contains 0.05 mole.

B. Determination of the number of mole in 4.5 kg Ca(OH)₂

Molar mass of Ca(OH)₂ = 40 + 2(16 + 1)

= 40 + 2(17)

= 40 + 34

= 74 g/mol

Mass of Ca(OH)₂ = 4.5 kg

= 4.5 × 1000

= 4500 g

Mole of Ca(OH)₂ =?

[tex]Mole = \frac{mass}{molar mass }[/tex]

Mole of Ca(OH)₂ = [tex]\frac{4500}{74}\\\\\\[/tex]

Mole of Ca(OH)₂ = 60.81 moles

Thus, 4.5 kg Ca(OH)₂ contains 60.81 moles

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The formula H2SO4 is representative of which of the following?A. an acid B. a catalyst C. an organic compound D. a base

Answers

Absolutely an acid ,because:

1)we it is sulfuric acid s molecular formula

2) in its shape H atom bonded with (O),not central atom

Answer:

A. An acid

Explanation:

Hello,

In inorganic chemistry, oxyacids are characterized by the presence of hydrogen, a nonmetal and oxygen as they are formed when an acid oxide (formed with a  nonmetal and oxygen) reacts with water. In this case, as the molecule has hydrogen, sulfur and oxygen, such constituting atoms match with the definition of an oxyacid, that is why H₂SO₄ is an acid.

Best regards.

How much heat is given off when 64 g liquid methanol at its freezing point changes to solid methanol?

Answers

Answer:

= 6.32 Joules

Explanation:

The heat given off by a substance while changing from liquid state to solid state without change in temperature is given by the formula;

Q = n×Lf

where, Q is the heat quantity, n is the number of moles and Lf is the molar heat of fusion. The methanol HF is 3.16 kJ/mol.

The number of moles = 64 g/32 g/mol

                                   = 2 moles

Therefore;

Heat = 2 moles × 3.16 kJ/mol

        = 6.32 Joules

Answer:

6.32 kJ

Explanation:

took the test

Name two things in the lab that are for safety

Answers

Answer:

Safety goggles and chemical fume hoods

Explanation:

For the reaction represented by the equation 2na + cl2 how many grams of sodium chloride can be produced from 500. g each of sodium and chlorine

Answers

Final answer:

The reaction between sodium And chlorine yields sodium chloride. Given 500 gms each of sodium and chlorine, approximately 500 g of sodium chloride can be produced.

Explanation:

The reaction 2Na + Cl2 produces sodium chloride or NaCl. To calculate the amount of sodium chloride produced from 500 g of sodium and 500 g of chlorine, we first need to know the molar mass of the elements involved. The molar mass of Sodium (Na) is 23 g/mol and Chlorine (Cl2) is 71 g/mol. Now, from the balanced equation, it is clear that 2 moles of Na (46 g) react with 1 mole of Cl2 (71 g) to produce 2 moles of NaCl, whose molar mass is 58 g/mol. Hence, 117 g of Na would react completely with 500 g of Cl2 to produce 500 g of NaCl approximately, making Sodium (Na) the limiting reactant. Therefore, from 500 g of each Sodium and Chlorine, we could theoretically produce around 500 g of Sodium Chloride (NaCl).

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Final answer:

Using stoichiometry, it is determined that 500 grams of chlorine is the limiting reactant and from this amount, 824.21 grams of sodium chloride can be produced from the reaction 2 Na + Cl2.

Explanation:

To determine how many grams of sodium chloride (NaCl) can be produced from 500 grams of sodium (Na) and 500 grams of chlorine (Cl2), we need to use stoichiometry and the balanced chemical equation:

2 Na (s) + Cl2 (g) → 2 NaCl (s)

First, we should convert the mass of the reactants to moles using their molar masses (Na = 22.99 g/mol, Cl2 = 70.90 g/mol). Then, we compare the mole ratio from the balanced equation to identify the limiting reactant. The limiting reactant will determine the maximum amount of product that can be formed.

For sodium: 500 g Na × (1 mol Na / 22.99 g Na) = ~21.75 mol Na

For chlorine: 500 g Cl2 × (1 mol Cl2 / 70.90 g Cl2) = ~7.05 mol Cl2

From the balanced equation, we know that 1 mole of Cl2 reacts with 2 moles of Na. Here, Cl2 is the limiting reactant, and it will determine the number of moles of NaCl that can be formed:

7.05 mol Cl2 × (2 mol NaCl / 1 mol Cl2) = 14.1 mol NaCl

To find the mass of NaCl produced, we multiply the moles of NaCl by its molar mass (NaCl = 58.44 g/mol):

14.1 mol NaCl × (58.44 g NaCl / 1 mol NaCl) = ~824.21 g NaCl

Therefore, 824.21 grams of NaCl can be formed from 500 grams each of Na and Cl2 when using the correct stoichiometry of the reaction.

What happens with the atomic numbers in nuclear equations?

Increase

Decrease

Conserved

Nothing

Answers

Answer:

Conserved

Explanation:

In balancing nuclear reaction equations, there is conservation of mass numbers and atomic numbers, i.e the sum of the mass number on the product side must be equal to the sum of mass numbers on the reactant side.

Also, the sum of the atomic numbers on the product side must be equal to the sum of the atomic numbers on the reactant side.

Note: A nuclear reaction is a process in which a nucleus reacts with an elementary particle.

Heat measures the average kinetic energy a substance's molecules.


TRUE


FALSE

Answers

Answer:

False this is like the definition of temperature

Explanation:

If the momentum of an electron were doubled, how would its wavelength change?

Answers

Answer:

If the momentum of an electron were doubled its wavelength would be shortened to half the original value.

Explanation:

The relation between the momentum and the wavelength of a particle is given by De Broglie's equation:

λ = h / p

Where, λ is the wavelength, h is Planck's constant, and p  is the momentum.

h = 6.63 × 10⁻³⁴ J.s

Therefore, as per De Broglie's equation, the momentum of an electron and its wavelength are inversely related, meaning that if the momentum of an electron were doubled its wavelength would be shortened to half the original value.

Cu ag and au are all in what group number

Answers

Answer:

Cu, Ag, and Au are all in the group number 11

Explanation:

To answer this question you must look at your periodic table.

The elements in the periodic table are ordered in increasing order of atomic number and elements with similar chemical properties, due to the same number of valence eletrons, lay in the same column.

The column in the periodic table corresponds to the chemical group, and,  in the most modern version, is identified with a number 1 through 18.

The elments Cu (copper), Ag (silver), and Au (gold), all metals, are in the same group (column) number 11.

The elements in the columns 3 trough 12 are transition metals. The atomic numbers of thise elements, which let you to find them easily in your periodic table, are:

Cu: 29 (it is the first element in the group)Ag: 47 (it is directly below Cu)Au: 79 (79 ( it is directly below Ag)

Those elements, along with platinum are paladium, are the metals with the lowest reactivity, which is the reason why they are found in nature in its pure form (not combined with other elements).

Cu, Ag, and Au are all in Group 11 of the periodic table, known for having eleven valence electrons and being part of the d-block transition metals. They appear in various transition series (Cu in the first, Ag in the second, and Au in the third) and can form d10 coordination complexes.

The elements Cu (Copper), Ag (Silver), and Au (Gold) all belong to Group 11 of the periodic table. These metals are collectively known as the coinage metals and are characterized by having eleven valence electrons. They are part of the d-block elements, specifically included in the transition metals category. Copper is in the first transition series, silver is part of the second, and gold falls within the third. The properties of these metals, such as their high conductivities and malleability, make them highly valuable and extensively used in coins, jewelry, and electronics.

Moreover, when these elements form complexes with coordination number 2, as seen with d10 metal ions like Cut, Ag+, and Aut, they typically exhibit a linear L-M-L structure. Such configurations can be useful in various applications including the extraction of gold from its ores.

Place the following in order of decreasing molar entropy at 298 k. H2 cl2 f2

Answers

cl2>F2>H2

we can do this by molar mass

Hydrogen - 1

clorine - 35 x2 = 70

flourine- 18 x 2 = 36

flourine - 18

Molar mass has a direct relationship with entropy. The order of decreasing molar entropy at 298K is F[tex]_2[/tex]> Cl[tex]_2[/tex] > H[tex]_2[/tex].

What is entropy?

Entropy is a measurable physical characteristic and a scientific notion that is frequently connected to a condition of disorder, unpredictability, or uncertainty. It has several applications in physics and chemistry, as well as in biological systems as well as how they relate to life.

The phrase and the idea are employed in many different contexts, including information theory and classical thermodynamics. Molar mass has a direct relationship with entropy. The order of decreasing molar entropy at 298K is F[tex]_2[/tex]> Cl[tex]_2[/tex] > H[tex]_2[/tex].

Therefore, the order of decreasing molar entropy at 298K is F[tex]_2[/tex]> Cl[tex]_2[/tex] > H.

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It is inappropriate to give a couple's shower.

True
False

Answers

The statement that a couples' shower is inappropriate is false. Couples' showers are a modern, inclusive celebration for both members of a couple and are deemed appropriate based on the couple's preference and cultural norms.

The assertion that it is inappropriate to give a couples' shower is false. A couples' shower is a modern take on traditional bridal showers, and is considered an appropriate event. It involves both members of the couple, regardless of gender, and allows guests who are close to both individuals to celebrate their union together. The appropriateness of a couples' shower is determined by the couple's preferences and the social norms of their community or culture.

Which solution below has the highest concentration of hydroxide ions?a. pH= 3.21b. pH= 7.00c. pH= 7.93d. pH= 12.59e. pH= 9.82

Answers

Answer:

The solution that has the highest concentration of hydroxide ions is d. pH = 12.59.

Explanation:

You can solve this question using just some chemical facts:

pH is a measure of acidity or alkalinity: the higher the pH the lower the acidity and the higher the alkalinity.The higher the concentration of hydroxide ions the lower the acidity or the higher the alkalinity of the solution, this is the higher the pH.

Hence, since you are asked to state the solution with the highest concentration of hydroxide ions, you just pick the highest pH. This is the option d, pH = 12.59.

These mathematical relations are used to find the exact concentrations of hydroxide ions:

pH + pOH = 14 ⇒ pOH = 14 - pH

pOH = - log [OH⁻] ⇒ [tex][OH^-]=10^{-pOH}[/tex]

Then, you can follow these calculations:

Solution    pH        pOH                            [OH⁻]

a.               3.21       14 - 3.21 = 10.79        antilogarithm of 10.79 = 1.6 × 10⁻¹¹

b.               7.00      14 - 7.00 = 7.00        antilogarithm of 7.00 = 10⁻⁷

c.                7.93      14 - 7.93 = 6.07        antilogarithm of 6.07 = 8.5 × 10⁻⁷

d.               12.59     14 - 12.59 = 1.41        antilogarithm of 1.41 = 0.039

e.               9.82      14 - 9.82 = 4.18        antilogarithm of 4.18 = 6.6 × 10⁻⁵

From which you see that the highest concentration of hydroxide ions is for pH = 12.59.

The pH with the highest hydroxide ion is 12.59

What is pH?

pH is the degree of acidity or alkalinity in a solution.

The lower the pH, the higher the acidity.The higher the pH the higher the basicity.

When the concentration is higher, it has more hydroxide ion.

Therefore, The pH with the highest hydroxide ion is 12.59 because the higher the pH the higher the concentration of the hydroxide ion.

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Silver tarnishing is an example of what type of change?
Physical change
Chemical change
Alchemical change
Temperature change

Answers

Answer:

that a chemical change

Explanation:

because it changing properties

It’s Chemical change

what did Rutherford observe that surprised him?

A. most of the alpha particles shot at the gold foil bounced back.

B. most of the alpha particles shot at the gold foil went straight through the foil.

c. none of the alpha particles went through the gold foil.

D. all of the alpha particles went straight through the gold foil.

Answers

Answer:

Some of the Alpha particles shot at the gold foil bounced back.

Explanation:

Rutherford observed that most of the alpha particles shot at the gold foil went straight through the foil.

Why Rutherford was surprised?

The alpha-particle scattering experiment is an important experiment that led Rutherford to give an accurate description of the distribution of positive and negative charges within the atom. Alpha particle source is placed in the lead cavity. The alpha particles emitted by the source are collimated into a narrow beam with the help of lead and slit.

The observations of Rutherford’s Alpha Scattering Experiment are: First, he observe that most of the α-particles that are bombarded towards the gold sheet pass away the foil without any deflection, and hence it shows most of the space is empty.

The correct answer is option B.

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which of the following best describes what happens to the force of attraction if the distance between two objects increase?
1.it varies
2.it decreases
3.it increases
4.it stays the same

Answers

Answer:

3.it increases

Explanation:

Final answer:

The force of attraction decreases when the distance between two objects increases, according to the inverse-square law for forces like gravity and electrostatic forces.

Explanation:

When the distance between two objects increases, the force of attraction between them decreases. This principle is observed in both gravitational and electrostatic forces. The magnitude of the force actually decreases as the square of the distance increases. If the distance doubles, the force between the objects would decrease to one fourth of its original value. Additionally, an increase in mass for an object in uniform circular motion will result in an increase of the required centripetal force to maintain the same speed.

The activation energy of a certain reaction is 40.1 kj/mol . at 26 ∘c , the rate constant is 0.0160s−1. at what temperature in degrees celsius would this reaction go twice as fast? express your answer with the appropriate units. view available hint(s)

Answers

Answer:

[tex]\boxed{\text{39 }^{\circ}\text{C}}[/tex]

Explanation:

We can use the Arrhenius equation:

[tex]\ln(\frac{k_2 }{k_1}) = \frac{E_{a} }{R}(\frac{1}{T_1} - \frac{1 }{T_2 })[/tex]

Data:

Eₐ = 40.1 kJ·mol⁻¹

k₁ = 0.0160 s⁻¹;              k₂ = 0.0320 s⁻¹

T₁ = 26 °C = 299.15 K; T₂ = ?  

Calculations:

[tex]\ln(\frac{0.0320}{0.0160}) = \frac{40 100 }{8.314}(\frac{ 1}{299.15}} - \frac{1 }{T_{2} })\\\\\ln2 = 4823(\frac{ 1}{299.15}} - \frac{1}{T_{2} }) \\\\\ln2 - 16.12 = -\frac{4823}{T_{2} }\\\\-15.43 = -\frac{4823}{T_{2} }\\\\T_{2} = \frac{4823}{15.43} =\textbf{312.6 K}[/tex]

T₂ = 312.6 K = 39 °C

The reaction will go twice as fast at [tex]\boxed{\text{39 }^{\circ}\text{C}}[/tex].

The temperature at which the reaction would go twice as fast, given an activation energy of 40.1 kJ/mol and an initial rate constant of 0.0160 s⁻¹ at 26 °C, is approximately 39.4 °C.

Solution

We can use the Arrhenius equation to solve this problem:

k = A * e^(-Ea / (R * T))

where:

k is the rate constant,Ea is the activation energy (40.1 kJ/mol),R is the gas constant (8.314 J/mol·K),T is the temperature in Kelvin,A is the frequency factor (which cancels out when comparing two temperatures).

Given that the rate constant at 26 °C (299 K) is 0.0160 s⁻¹ and we need to find the temperature where the rate constant doubles (0.0320 s⁻¹), we can use the two-point form of the Arrhenius equation:

ln(k₂ / k₁) = -Ea / R * (1/T₂ - 1/T₁)

where:

k₁ = 0.0160 s⁻¹, T₁ = 299 Kk₂ = 0.0320 s⁻¹and we need to find T₂.

Rearrange the equation to solve for T₂:

ln(0.0320 / 0.0160) = -40,100 J/mol / 8.314 J/mol·K * (1/T₂ - 1/299 K)

Solve for the ratio of rate constants:

ln(2) = 40,100 / 8.314 * (1/299 K - 1/T₂)
0.693 = 4,822.6 * (1/299 K - 1/T₂)
(1/299 K - 1/T₂) = 0.693 / 4,822.6
(1/299 K - 1/T₂) ≈ 0.0001437

Solve for 1/T₂:

1/T₂ = 1/299 K - 0.0001437
1/T₂ ≈ 0.003346 - 0.0001437
1/T₂ ≈ 0.0032023
T₂ ≈ 312.4 K

Convert T₂ to degrees Celsius:

T₂ - 273 ≈ 39.4 °C

Therefore, the temperature at which the reaction would go twice as fast is approximately 39.4 °C.

What element on the periodic table is named after the european capital where it was discovered in 1923?

Answers

Answer:

The element is Hafnium

Explanation:

Hi, Hafnium was discovered in 1923 by George Charles de Hevesy y Dirk Coster in Denmark. It's name was given after the capital of that country: Copenhagen which name in latin is Hafnia.

For the reaction CH4 + 2O2 → CO2 + 2H2O, how many grams of water are produced from thecombustion of 6.35 moles of methane?

Answers

Answer:

228.6 g of H₂O

Explanation:

the balanced equation for the combustion of methane is as follows

CH₄ + 2O₂ ---> CO₂ + 2H₂O

molar ratio of CH₄ to H₂O is 1:2

when 1 mol of CH₄ reacts with excess O₂, 2 mol of H₂O is formed

therefore when 6.35 mol of CH₄ reacts - 2 x 6.35 mol = 12.7 mol of H₂O is formed

therefore mass of H₂O formed is - 12.7 mol x 18 g/mol = 228.6 g of H₂O is formed

Final answer:

Using the stoichiometry of the balanced chemical equation CH4 + 2O2 → CO2 + 2H2O, 6.35 moles of methane produce 12.7 moles of water, which is equal to 228.854 grams of water.

Explanation:

To find out how many grams of water (H₂O) are produced from the combustion of 6.35 moles of methane (CH₄), we need to use the stoichiometry of the balanced chemical equation, which is CH₄ + 2O₂ → CO₂ + 2H₂O.

According to the equation, each mole of methane produces 2 moles of water. Therefore, 6.35 moles of methane will produce 6.35 * 2 = 12.7 moles of water. The molar mass of water is 18.02 g/mol, so the total mass of water produced is 12.7 moles * 18.02 g/mol = 228.854 g of H₂O.

Why is the answer C for this problem?

Answers

Answer:

[tex]\boxed{\text{(C) X}$_{3}$P$_{2}}[/tex]

Explanation:

Step 1. Identify the Group that contains X

We look at the consecutive ionization energies and hunt for a big jump between them

[tex]\begin{array}{crc}n & IE_{n} & IE_{n} - IE_{n-1}\\1 & 730 & \\2 & 1450 & 720\\3 & 7700 & 6250\\4 & 10500 & 2800\\\end{array}[/tex]

We see a big jump between n = 2 and n = 3. This indicates that X has two valence electrons.

We can easily remove two electrons, but the third electron requires much more energy. That electron must be in the stable, filled, inner core.

So, X is in Group 2 and P is in Group 15.

Step 2. Identify the Compound

X can lose two valence electrons to reach a stable octet, and P can do the same by gaining three electrons.

We must have 3 X atoms for every 2 P atoms.

The formula of the compound is [tex]\boxed{\text{X}$_{3}$P$_{2}}$}[/tex].

given the equation 2Na+Cl2 ​ →2NaCl How many moles of NaCl will be produced from 59.0 grams of Na, assuming Cl is available in excess?

Answers

I would use dimensional analysis for this problem. You would start with the given amount of Na which is 59.0g. You are trying to find the moles of NaCl.

(59.0g Na)*(1 mol Na)/(22.99 g Na)*(2 mol NaCl)/(2 mol Na)=

2.57 mol NaCl

The units will cancel out until you are left with moles of NaCl. The answer has the correct number of significant figures (3 sig figs).

Answer: 2.56 moles

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]    

[tex]\text{Moles of} Na=\frac{59.0g}{23g/mol}=2.56moles[/tex]

[tex]2Na(s)+Cl(g)\rightarrow 2NaCl(s)[/tex]

Na is the limiting reagent as it limits the formation of product and chlorine is the excess reagent.

According to stoichiometry :

2 moles of Na produce = 2 moles of NaCl

Thus 2.56 moles of Na produce =[tex]\frac{2}{2}\times 2.56=2.56moles[/tex]  of NaCl

Thus 2.56 moles of NaCl are produced.

What is the fraction of the hydrogen atom's volume that is occupied by the nucleus? the bohr radius is 0.529×10−10m?

Answers

The radius of an electron in the third shell of the hydrogen atom, according to the Bohr model, is calculated as 4.7628 x 10⁻¹⁰ meters.

To calculate the radius of an electron in the third shell (n=3) of the hydrogen atom according to the Bohr model of the hydrogen atom, you use the formula that relates the main quantum number (n) to the radius of the electron's orbit. The radius of an orbit (rn) in the Bohr model is given by the equation rn = n2 imes ao, where ao is the Bohr radius and equals 5.292  imes 10
11 m. For the third shell, n=3, so the calculation is r3 = 32  imes 5.292 imes 10-11 m = 9 imes 5.292 imes 10-11 m.

Therefore, the radius of an electron in the third shell is r3 = 47.628 imes 10-11 m = 4.7628 imes 10-10 m. Keep in mind that while this model provides insight, it has been refined by quantum mechanics.

A solution of a base differs from a solution of an acid in that the solution of a base?A. is able to conduct electricity B. is able to cause an indicator color change C. has a great [H3O+] D. has a great [OH-]

Answers

Answer:

Option D. has a great [OH⁻]

Explanation:

1) Both acids and bases ionize in aqueous solutions so they are able to conduct electricity.

The ions, being charged particles, when flow through the solution are charge carriers, then they conduct electricity.

So, the option A does not state a difference between a solution of a base and a solution of an acid.

2) Both acids and bases are able to cause an indicator color change.

The usufulness of the indicators is that they are able to change of color when the pH changes either from acid to basic or from basic to acid. There are different indicators because none is suitable for the whole range of pH, but the statement B is not how solutions of base and acids differ.

3) The model of Arrhenius for acids and bases states that an acid is a substance that ionizes in water releasing H⁺ ions (this is equivalent to H₃O⁺) and a base is a substance that releases OH⁻ ions in water. Then, acids have a greater concentration of H₃O⁺ (so option C is not true for a solution of a base) and bases  have a greater concentraion of OH⁻, making the option D. true.

Answer:

D. Has a great [OH-]

Explanation:

Castle learning

What is the coefficient of the acid that produces AlCl3 in the reaction mixing Al(OH)3 and HCl after the equation has been balanced?


1

3

2

4




Answers

Answer:

3.

Explanation:

Al(OH)₃ reacts with HCl to produce AlCl₃ and water according to the balanced equation:

Al(OH)₃ + 3 HCl → AlCl₃ + 3H₂O,

It is clear that 1.0 mole of Al(OH)₃ reacts with 3.0 mole of HCl to produce 1.0 mole of AlCl₃ and 3.0 moles of H₂O,

So, the coefficient of HCl is 3.

Calculate the pka of hypochlorous acid. The ph of a 0.015 m solution of hypochlorous acid has a ph of 4.64.

Answers

Answer:

pKa = 7.46

Explanation:

1) Data:

a) Hypochlorous acid = HClO

b) [HClO} = 0.015

c) pH = 4.64

d) pKa = ?

2) Strategy:

With the pH calculate [H₃O⁺], then use the equilibrium equation to calculate the equilibrium constant, Ka, and finally calculate pKa from the definition.

3) Solution:

a) pH

pH = - log [H₃O⁺]

4.64 = - log [H₃O⁺]

[tex][H_3O^+]= 10^{-4.64} = 2.29.10^{-5}[/tex]

b) Equilibrium equation: HClO (aq) ⇄ ClO⁻ (aq) + H₃O⁺ (aq)

c) Equilibrium constant: Ka =  [ClO⁻] [H₃O⁺] / [HClO]

d) From the stoichiometry: [CLO⁻] = [H₃O⁺] = 2.29 × 10 ⁻⁵ M

e) By substitution: Ka = (2.29 × 10 ⁻⁵ M)² / 0.015M = 3.50 × 10⁻⁸ M

f) By definition: pKa = - log Ka = - log (3.50 × 10 ⁻⁸) = 7.46

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