4. How many electrons are in the electron shell closest to the nucleus?

Answer:

Suppose that you add 29.2 g of an unknown molecular compound to 0.250 kg of benzene, which has a K f of 5.12 oC/m. With the added solute, you find that there is a freezing point depression of 2.78 oC compared to pure benzene. What is the molar mass (in g/mol) of the unknown compound

Explanation:

The mass of nonvolatile solute added is ---- 29.2g

The mass of solvent benzene is ---- 0.250kg = 250g

The Kf value of benzene is ---- 5.12^oC/m.

Depression in the freezing point of the solution is --- 2.78^oC.

What is the molar mass of the unknown solute?

[tex]The depression in freezing point = Kf * molality of the solution\\molality of the solution = \frac{mass of solute}{molar mass of solute}*\frac{1}{mass of solvent in kg}[/tex]

Substitute the given values in this formula to get the molar mass of unknown solvent:

[tex]molality=\frac{29.2g}{M} * \frac{1}{0.250kg} \\depression in freezing point:\\2.78^oC=5.12^oC/m * \frac{29.2g}{M} * \frac{1}{0.250kg} \\\\=>M=5.12^oC/m * \frac{29.2g}{2.78^oC} * \frac{1}{0.250g} \\\\\\=>M=215.1g/mol[/tex]

Hence, the molar mass of unknown solute is --- 215g/mol.

Answer:

mixture

Explanation:

an example of one is a salad you can separate the ingredients

Answer: 54 molecules of water will be formed in the reaction.

Explanation:

A balanced chemical equation is one where all the individual atoms are equal on both sides of the reaction. It follows the law of conservation of mass.

For the given unbalanced chemical equation, the balanced equation follows:

[tex]2C_8H_{18}+25O_2\rightarrow 16CO_2+18H_2O[/tex]

We are given:

Molecules of [tex]C_8H_{18}[/tex] = 6

Molecules of [tex]O_2[/tex] = 75

By the stoichiometry of the reaction:

If 2 molecules of [tex]C_8H_{18}[/tex] produces 18 molecules of water

So, 6 molecules of [tex]C_8H_{18}[/tex] will produce = [tex]\frac{18}{2}\times 6=54[/tex] molecules of water

Hence, 54 molecules of water will be formed in the reaction.

Answer:

I choose D option because may be it's correct

I believe it is c

Explanation:

because if u think about it and also do some research you would see that the circulatory system is a strong part of your body which can help u through natural defences if this sounds weird it's all in research but if it ain't c dont blame me for ruining your life- lol but yeah I think its c

Answer:

There are [tex]9[/tex] electrons in this atom.

Explanation:

Electron configuration of this atom: [tex]1s^2\, 2s^2\, 2p^5[/tex].

The electron orbitals of an atom are denoted as [tex]1s[/tex], [tex]2s[/tex], [tex]2p[/tex], [tex]3s[/tex], [tex]3p[/tex], etc. At any given time, an electron in this atom is located in exactly one orbital.

The electron configuration of an atom gives the number of electrons in each orbitals of this atom.

For example, in this atom, the superscript "[tex]2[/tex]" on the right of "[tex]1s[/tex]" means that there are two electrons in the [tex]1s\![/tex] orbital of this atom. Hence, [tex]1s^2\, 2s^2\, 2p^5[/tex] would translate to:

Hence, there would be [tex]2 + 2 + 5 = 9[/tex] electrons in total in this atom.

Answer:

40 atm

Explanation:

Boyles law states that the pressure exerted on a gas is inversely proportional to the volume it occupies provided that the temperature is held constant. It is given by:

P ∝ 1/V

PV = constant

P₁V₁ = P₂V₂

Given that V₁ = initial volume = 200 ml, P₁ = initial pressure = 2 atm, V₂ = final  volume = 10 ml, P₂ = final pressure. Hence:

2 atm * 200 ml = P₂ * 10 ml

P₂ = (2 atm * 200 ml) / 10 ml

P₂ = 40 atm

Answer: The equation is [tex]_{29}^{63}\textrm{Cu}\rightarrow _{30}^{63}\textrm{Zn}+_{-1}^0e[/tex]

Explanation:

Neutron capture is a process where a neutron is converted into a proton and an electron. The released particle is known as beta particle and it carries a charge of -1 units and has a mass of 0 units. It is also known as an electron. The general equation for this process is:

[tex]_Z^A\textrm{X}\rightarrow _{Z+1}^A\textrm{Y}+ _{-1}^0\e[/tex]

The nuclear equation for the formation of zinc via neutron capture of copper follows:

[tex]_{29}^{63}\textrm{Cu}\rightarrow _{30}^{63}\textrm{Zn}+_{-1}^0e[/tex]

Answer:

[tex]pH = - log[H {}^{ + } ] \\ 8.8 = - log[H {}^{ + } ] \\ \: [H {}^{ + } ] = {10}^{ - 8.8} \\ [H {}^{ + } ] = 1.585 \times {10}^{ - 9} \: mol {dm}^{ - 3} [/tex]

Answer:

When pressure increases, there is no effect on the reaction because volume is constant.

Answer:

46.525 u

Explanation:

From the question given above, the following data were obtained:

Isotope A (⁴⁶Ti)

Abundance (A%) = 77.100%

Mass of A = 45.95263 u

Isotope B (⁴⁸Ti):

Abundance (B%) = 17.100%

Mass of B = 47.94795 u

Isotope C (⁵⁰Ti):

Abundance (C%) = 5.800%

Mass of C = 49.94479 u

Average atomic mass =?

The average atomic mass of titanium can be obtained as follow:

Average = [(Mass of A × A%)/100] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100]

= [(45.95263 × 77.1)/100] + [(47.94795 × 17.1)/100] + [(49.94479 × 5.8)/100]

= 35.429 + 8.199 + 2.897

= 46.525 u

Therefore, the average atomic mass of titanium is 46.525 u

Answer:

C₆H₁₀NO

Explanation:

In order to arrive at a molecular formula we have to make some assumptions and they are

Assuming there is one ( 1 ) N and one ( 1 ) O that is present in the said molecule

Total mass =   29.998

next step: subtract the total mass from 112.0499 = 82.501

next : assume the presence of 6 carbon atoms in said molecule

Total mass =  6 * 12 = 72

Mass of Hydrogens = 82.501 - 72 = 10.501

∴ number of hydrogens = 10.501 / 1.0078  ≈ 10

Hence Total mass = 29.998 + 82.501  ≈ 112.0499

Finally Molecular formula = C₆H₁₀NO

Answer:

CF4

Molecular geometry- tetrahedral

Electron geometry- tetrahedral

NF3

-molecular geometry - trigonal pyramidal

Electron geometry - tetrahedral

OF2

Molecular geometry - bent

Molecular geometry - tetrahedral

H2S

Molecular geometry- bent

Electron geometry - tetrahedral

Explanation:

According to Valence Shell Electron Pair Repulsion Theory, the shape of a molecule depends on the number of electron pairs on the valence shell of the central atom in the molecule.

For all the compounds listed, the central atom has four points of electron density. This correspond to a tetrahedra electron pair geometry. The presence of lone pairs on the central atom of OF2,NF3 and H2S accounts for the departure of the observed molecular geometry from the geometry and idealized bond angle predicted on the basis of the VSEPR theory.

Answer: Molarity of the unknown calcium hydroxide solution is 0.217 M.

Explanation:

Given: [tex]V_{1}[/tex] = 50.00 mL,     [tex]M_{1}[/tex] = ?

[tex]V_{2}[/tex] = 43.43 mL,         [tex]M_{2}[/tex] = 0.250 M

Formula used is as follows.

[tex]M_{1}V_{1} = M_{2}V_{2}[/tex]

Substitute the values into above formula as follows.

[tex]M_{1}V_{1} = M_{2}V_{2}\\M_{1} \times 50.00 mL = 0.250 M \times 43.43 mL\\M_{1} = \frac{0.250 M \times 43.43 mL}{50.00 mL}\\= 0.217 M[/tex]

Thus, we can conclude that molarity of the unknown calcium hydroxide solution is 0.217 M.

The nuclear fusion results in the liberation of large amount of energy by the conversion of mass to energy. Thus, option B is correct.

The nuclear fusion has been a type of nuclear reaction in which the reaction of the two nuclei results in the nuclei with mass smaller than the reactants. In nuclear reactions, there has been the liberation of large amount of energy.

The energy released in the nuclear fusion has been formed by the conversion of the mass. Since, the formed product has nuclei with the mass smaller than the reactants, the remaining mass of the reactants has been converted to the energy.

Thus, in nuclear fusion, the energy released has been produced from the conversion of mass to energy. Thus, option B is correct.

For more information about the nuclear fusion, refer to the link:

https://brainly.com/question/16021285

Answer:

317 mL.

Explanation:

From the question given above, the following data were obtained:

Initial volume (V₁) = 250 mL

Initial temperature (T₁) = 373.15 K

Final temperature (T₂) = 473.15 K

Pressure = Constant

Final volume (V₂) =?

The final volume of the air sample can be obtained by using the Charles' law equation as illustrated below:

V₁/T₁ = V₂/T₂

250 / 373.15 = V₂ / 473.15

Cross multiply

373.15 × V₂ = 250 × 473.15

373.15 × V₂ = 118287.5

Divide both side by 373.15

V₂ = 118287.5 / 373.15

V₂ = 317 mL

Therefore, the final volume of the air sample is 317 mL

Answer:

1.78 × 10⁹ μg

Explanation:

We have to convert 1.78 kg to μg.

Step 1: Convert 1.78 kilograms to grams

We will use the conversion factor 1 kg = 10³ g.

1.78 kg × 10³ g/1 kg = 1.78 × 10³ g

Step 2: Convert 1.78 × 10³ grams to micrograms

We will use the conversion factor 1 g = 10⁶ μg.

1.78 × 10³ g × 10⁶ μg/1 g = 1.78 × 10⁹ μg

Answer:

22/7 × [tex]10^{2}[/tex]

Explanation:

The area of a circle can be found out using π[tex]r^{2}[/tex]. Since r is the radius so if they multiply, they will give you an area of a square then multiply by 22/7 since it is a circle.

The surface area of the Tambourine at the given diameter of 10 inches is determined as 78.54 square inches.

A Tambourine has circular shape, and the area of the Tambourine can be determined by applying formula for area of a circle as shown below;

A = πr²

where;

r  = ¹/₂D

r = ¹/₂ x 10 in

r = 5 in

A = π(5)²

A = 25π in²

A = 78.54 in²

Thus, the surface area of the Tambourine at the given diameter of 10 inches is determined as 78.54 square inches.

Learn more about surface area here: https://brainly.com/question/76387

Answer:

it will be no.A genotype

Answer:

D

Explanation:

pH=-log(x)

x=0.001M,pH=3

x=0.01M,pH=2

x=0.1M,pH=1

x=1M,pH=0

Highest pH is for option D

Answer:

D.

Explanation:

The highest pH is D because

0.01 M HCL => 2

0.1 M HCL => 1

1 M HCL => 0

0.001 M HCL => 3

so the answer is D.

Answer: The pH of the resulting solution will be 3.001

Explanation:

Molarity is calculated by using the equation:

[tex]\text{Molarity}=\frac{\text{Moles}}{\text{Volume}}[/tex]          ......(1)

We are given:

Moles of NaOH = 0.0224 moles

Molarity of nitrous acid = 0.475 M

Molarity of sodium nitrite = 0.302 M

Volume of solution = 150 mL = 0.150 L          (Conversion factor: 1 L = 1000 mL)

Putting values in equation 1, we get:

[tex]\text{Moles of nitrous acid}=(0.475mol/L\times 0.150L)=0.07125mol[/tex]

[tex]\text{Moles of sodium nitrite}=(0.302mol/L\times 0.150L)=0.0453mol[/tex]

The chemical equation for the reaction of nitrous acid and NaOH follows:

                   [tex]HNO_2+NaOH\rightleftharpoons NaNO_2+H_2O[/tex]

I:                0.07125     0.0224     0.0453

C:             -0.0224     -0.0224   +0.0224

E:              0.04885         -          0.0677

The power of the acid dissociation constant is the negative logarithm of the acid dissociation constant. The equation used is:

[tex]pK_a=-\log K_a[/tex]        ......(2)

We know:

[tex]K_a[/tex] for nitrous acid = [tex]7.2\times 10^{-4}[/tex]

Using equation 2:

[tex]pK_a=-\log (7.2\times 10^{-4})=3.143[/tex]

To calculate the pH of the acidic buffer, the equation for Henderson-Hasselbalch is used:

[tex]pH=pK_a+ \log \frac{\text{[conjugate base]}}{\text{[acid]}}[/tex]         .......(3)

Given values:

[tex][NaNO_2]=\frac{0.0677}{0.150}[/tex]

[tex][HNO_2]=\frac{0.04885}{0.150}[/tex]

[tex]pK_a=3.143[/tex]

Putting values in equation 3. we get:

[tex]pH=3.143-\log \frac{(0.0677/0.150)}{(0.04885/0.150)}\\\\pH=3.143-0.142\\\\pH=3.001[/tex]

Hence, the pH of the resulting solution will be 3.001

Answer:

b. 0.3 mol/L is the closest.

Explanation:

A molar solution of a substance contains 1 mole per liter of solution

So if we have 2 moles in 6 liters the there are 2/6 =1/3 of a mole in 1 liter.

The complete question is as follows: 171 g of sucrose ( MW of 342, melting point 186 oC, boiling point very high, and vapor pressure is negligible) is dissolved in one liter of water at 25 oC. At 25 oC the vapor pressure of water is 24 mmHg. Which value is closest to the vapor pressure (VP) of this solution at 25 oC?

a. 16mm Hg

b. 24mm Hg  

c. 20mm Hg  

d. 12mm Hg

Answer: The vapor pressure (VP) of this solution at [tex]25^{o}C[/tex] is closest to the value 24 mm Hg.

Explanation:

Given: Mass of sucrose = 171 g

Mass of water = 1 L = 1000 g

Vapor pressure of water = 24 mm Hg

As moles is the mass of substance divided by its molar mass. Hence, moles of water (molar mass = 18.02 g) is calculated as follows.

[tex]Moles = \frac{mass}{molar mass}\\= \frac{1000 g}{18.02 g/mol}\\= 55.49 mol[/tex]

Similarly, moles of sucrose (molar mass = 342 g/mol) is as follows.

[tex]Moles = \frac{mass}{molar mass}\\= \frac{171 g}{342 g/mol}\\= 0.5 mol[/tex]

Total moles = 55.49 + 0.5 mol = 55.99 mol

Mole fraction of water is as follows.

[tex]Mole fraction = \frac{moles of water}{total moles}\\= \frac{55.49}{55.99}\\= 0.99[/tex]

Formula used to calculate vapor pressure of the solution is as follows.

[tex]P_{i} = P^{o}_{i} \times \chi_{i}[/tex]

where,

[tex]P_{i}[/tex] = vapor pressure of component i over the solution

[tex]P^{o}_{i}[/tex] = vapor pressure of pure component i

[tex]\chi_{i}[/tex] = mole fraction of i

Substitute the values into above formula to calculate vapor pressure of water as follows.

[tex]P_{i} = P^{o}_{i} \times \chi_{i}\\= 24 mm Hg \times 0.99\\= 23.76 \\or 24 mm Hg\\[/tex]

Thus, we can conclude that the vapor pressure (VP) of this solution at [tex]25^{o}C[/tex] is closest to the value 24 mm Hg.

Answer:

C8H16 (Ethylcyclohexane).

Explanation:

From the given information:

Compound A is an alkene because it interacts with 1 unit of hydrogen across a palladium catalyst.

Also, we are given another hint that:

Compound A needs 4 equivalence of H2 to hydrogenate under circumstances that decrease aromatic rings, indicating that it is a phenyl substituted alkene.

Compound A with formula C8H8 reacts instantly with KMnO4 to produce CO2, as well as carboxylic acid, points out that Compound acts as a terminal alkene.

Therefore, we can opine that compound A is a terminal phenyl substituted alkene whose formula = C8H8 (Styrene)

The diagrammatic expression of the compound can be seen below.

However, in the presence of the palladium catalyst, the reduction of Compound A with 4 units of hydrogen produces Compound B: C8H16 (Ethylcyclohexane).

Answer:

See explanation

Explanation:

According to Bronsted-Lowry definition of acids/bases, an acid is a proton donor while a base is a proton acceptor.

Hence, in a reaction, the species that donate protons are strong acids while the species that accept protons are strong bases.

Hence, HSO4- is a stronger acid than H2C2O4 and SO42- is a weaker base than HC2O4-

Note that the conjugate base of a strong acid is a weak base and vice versa.

Answer: It's used in chemistry to measure the concentration of chemical solutions.

Explanation:

Beer's Law is used in chemistry to measure the concentration of chemical solutions, to analyze oxidation, and to measure polymer degradation.

The law also describes the attenuation of radiation through the Earth's atmosphere

Answer:

true because the bonds cannot be broken down

Answer:

B(OH)₃ + H₂O = B(OH)₄⁻ + H⁺

Explanation:

Let's consider Arrhenius acid-base theory:

Boric acid, B(OH)₃ reacts with water according to the following equation.

B(OH)₃ + H₂O = B(OH)₄⁻ + H⁺

As we can see, boric acid releases H⁺ in aqueous media. Thus, it is an acid.

Answer:

1.806 × 10²⁴ atoms

Explanation:

To obtain the number of atoms a substance contain, we have to multiply the number of moles in that substance (n) by Avogadro's number, which is 6.02 × 10²³.

According to this question, a sample of carbon tetrachloride (CCl4) contains 3 moles of the substance. The number of atoms in CCl4 is calculated thus:

number of atoms = 3 × 6.02 × 10²³

number of atoms = 18.06 × 10²³

number of atoms = 1.806 × 10²⁴ atoms.