A. After the label fell off a bottle containing a clear liquid believed to be benzene, a chemist measured the density of the liquid to verify its identity. A 25.0-mL portion of the liquid had a mass of 21.95 gg. A chemistry handbook lists the density of benzene at 15∘C∘C as 0.878 g/mg/mL. Is the calculated density in agreement with the tabulated value?
B. An experiment requires 15.0 g of cyclohexane, whose density at 25oC is 0.7781 g/mL. What volume of cyclohexane should be used?
C. A spherical ball of lead has a diameter of 5.0 cm. What is the mass of the sphere if lead has a density of 11.34 g/cm3?

Answer: 1024

Linear search's runtime is proportional to the number of list elements.

Answer:

The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.

Explanation:

The hot metal at 150 °C loses heat energy by conduction to the surrounding air molecukes and as such cools down, the cooler metal consists of lesser enery to power the movement of the molecules of the metal hence the metal molecules slows down in their movement as seen in the equation of heat and temperature

ΔH = m×C×ΔT where ΔH is the change in heat energy (heat loss of the metal, C is the heat capacity and ΔT is the temperature change

For the surrounding air that experiences increase in temperature the same process follows leading to increase in the kinetic energy of the air molecules and decrease in kinetic energy of the metal molecules as shown in the formula

K = [tex]\frac{3}{2}[/tex]×[tex]\frac{R}{N_{A} }[/tex]×T where K = Kinetic Energy, R = gas constant (8.314J/mol×K) and [tex]N_{A}[/tex] = Avogadros number (6.022×[tex]10^{23}[/tex] atoms/mol)

Answer:

d

Explanation:

Answer: Option (A) is the correct answer.

Explanation:

When we increase the temperature of a chemical reaction then molecules of the given reaction will gain kinetic energy. As a result, they will come into motion and then collide frequently with each other.

For a reaction to increase its rate it is important that the particles must collide in a correct orientation.

Thus, we can conclude that the rate of a reaction generally increase with increased temperature because at higher temperatures, molecules are more likely to collide with each other in the correct orientation.

Final answer:

The rate of a reaction increases with temperature due to more frequent collisions, collisions with greater energy exceeding the activation energy, and a higher likelihood of correct molecular orientation during these collisions.

So, correct options are A, B, and D.

Explanation:

The rate of a reaction generally increases with increased temperature for multiple reasons. At higher temperatures, molecules move more quickly which leads to an increase in the frequency of collisions between them. Furthermore, with the rise in kinetic energy, there is a greater chance that these collisions will have enough activation energy to result in a reaction. Also, as molecules move faster, they are more likely to collide in the correct orientation to instigate a reaction.

Options A and B are correct because molecules are more likely to collide and do so with the correct orientation at higher temperatures. Option D is also correct because the increase in kinetic energy means more collisions will have the required activation energy. However, Option C is not accurate because the potential energy difference between reactants and products does not depend on temperature.

Answer:

It increases by a factor of eight

Explanation:

When temperature is held constant, gas pressure changes according the volume, in undirectly proportion.

Volume increases →  Pressure decreases

Volume decreases → Pressure increases

As volume gas, was reducted from 4L to 0.5L, it was reduced by 1/8, so the pressure gas was increased by a factor of eight.

Answer:

It increases by a factor of eight.

Explanation:

Answer:

The formula of the scandium chloride produced in the reaction is ScCL₃

Explanation:

With the given data, you can know the molar relationship between Sc and H₂ (molar ratio) to determine the reaction stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction).

Then: [tex]molar ratio=\frac{moles Sc}{moles H_{2} }[/tex]

Knowing that:

and knowing that the number of moles (n) of a compound can be calculated as: [tex]n=\frac{mass}{molar mass}[/tex]

Then:

So:

[tex]molarratio=\frac{0.047}{0.071}[/tex]

Then it is possible to say that the molar ratio is approximately equal to [tex]\frac{2}{3}[/tex]. This indicates that by stoichiometry 2 moles of Sc are needed to produce 3 moles of H₂.

So:

2 Sc + HCl → ScCL₃ + 3 H₂

The law of conservation of matter states that since no atom can be created or destroyed in a chemical reaction, the number of atoms that are present in the reagents has to be equal to the number of atoms present in the products.

Then, balancing the equation so that the same amount of moles of each element on each side of the equation is obtained:

2 Sc + 6 HCl → 2 ScCL₃ + 3 H₂

The formula of the scandium chloride produced in the reaction is ScCL₃

Final answer:

The enthalpy of combustion of two isomers with the same molecular formula will be different due to their different structural arrangements. The rod-shaped n-pentane has less possible vibrational and rotational motions compared to the almost spherical neopentane.

Explanation:

The enthalpy of combustion of two isomers with the same molecular formula will be different. Isomers are compounds that have the same molecular formula but different structural arrangements. For example, the isomers of C4H10 are n-butane and isobutane. The balanced chemical equations for their combustion reactions are:

n-Butane: C4H10 + 6.5O2 → 4CO2 + 5H2O

Isobutane: C4H10 + 6.5O2 → 4CO2 + 5H2O

When calculating the combustion enthalpy from the standard enthalpies of formation of products and reactants, the difference in enthalpy will be due to the different standard enthalpies of combustion of the two isomers.

The rod-shaped n-pentane has less possible vibrational and rotational motions than the almost spherical neopentane. This is because neopentane is a more compact, three-dimensional molecule, while n-pentane is a linear molecule. Linear molecules have fewer degrees of freedom and therefore have fewer potential vibrational and rotational motions compared to more complex, three-dimensional molecules like neopentane.

The enthalpies of combustion for isomers are different due to structural variations. N-pentane has more vibrational and rotational motions compared to neopentane.

'We expect the enthalpy of combustion of two isomers to be different. The molecular formulas of two molecules are isomers, so the balanced chemical equations for the two combustion reactions are very similar. In calculation of combustion enthalpy from standard enthalpies of formation of products and reactants, the difference will be in the standard enthalpies of combustion of the two molecules.'

The rod-shaped n-pentane has more possible vibrational and rotational motions than the almost spherical neopentane.

Answer: B) hydrogen bonding

Explanation:

A) An ionic bond is formed when an element completely transfers its valence electron to another element.

B) Hydrogen bonds are special type of dipole dipole forces which are formed when hydrogen bonds with an electronegative element.

DNA strands are held together by hydrogen bonds between the bases on one strand and those on the other. Adenine and thymine have two hydrogen bonds between them while cytosine and guanine have three hydrogen bonds between them.

C) Non-polar covalent bond is defined as the bond which is formed when there is no difference of electronegativities between the atoms.

D) A polar covalent bond is defined as the bond which is formed when there is a difference of electronegativities between the atoms.

When DNA is replicated, the two strands unzip temporarily. The strands are held together by hydrogen bonding.

When DNA is replicated, the two strands temporarily unzip or separate from each other. The type of bonding that holds the strands together is hydrogen bonding. Hydrogen bonding occurs between the nitrogenous bases of the DNA strands.

These bases, adenine (A), thymine (T), cytosine (C), and guanine (G), form complementary base pairs with each other, with adenine pairing with thymine and cytosine pairing with guanine.

The hydrogen bonds between these base pairs keep the two DNA strands connected.

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Answer:

The answer to your question is  36.9 pounds

Explanation:

Data

density = 1 g/ml

mass = ?

volume = 16.743 L

- To solve this problem use the formula of density.

density = mass / volume

- Solve for mass

Mass = density x volume

- Convert volume to ml

                    1000 ml --------------- 1 L

                      x          ---------------- 16.743 L

                      x = (16.743 x 1000) / 1

                      x = 16743 ml

- Substitution

Mass = (1 g/ml)(16743 ml)

Simplification and result

Mass = 16743 g

- Convert mass to pounds

               1 pound ------------------ 453.58 g

                x            ------------------ 16743 g

                x = (16743 x 1) / 453.58

                x = 36.9 pounds

The mass of 16.743 L of water in pounds can be calculated as approximately 36.904 pounds.

To calculate the mass of water in pounds, we first determine the mass in grams using the given water volume and density.

Since the density of water is 1.00000 g/mL, and we know that 1 L is equal to 1000 mL, we multiply the volume in liters by the density in g/mL and by 1000 to get mass in grams.

This gives us 16.743 L * 1.00000 g/mL * 1000 = 16743 grams.

Converting grams to pounds, we know 1 pound is approximately 453.592 grams

So, the mass of water is then 16743 g / 453.592 g/lbs = 36.904 lbs. Therefore, the mass of 16.743 L of water is approximately 36.904 pounds.

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Answer:

[tex]m=22.3\ kg[/tex]

Explanation:

The expression for centrifugal force is shown below as:-

[tex]F=\frac{m\times v^2}{r}[/tex]

Where, m is the mass of the object = ?

v is the velocity of the object = 7.60 m/s

r is the radius

F is the force = 222 N

Diamter = 11.6 m

Radius = d/2 = 11.6 m/2 = 5.8 m

Applying the values in the above expression as:-

[tex]222=\frac{m\times {7.60}^2}{5.8}[/tex]

[tex]57.76m=1287.6[/tex]

[tex]m=22.3\ kg[/tex]

Answer:

2

Explanation:

To answer this correctly, we need to make a reference to the pH scale. Here we know that pH 1-6 stands for acidity where the smaller the value, the higher the concentration of H3O+ and the higher the acidity. Also, pH 7 stands for neutral, there is an interpreted balance here, where the concentrations are averagely equal. Also , we have pH 8 to 14 where we have the alkalinity, the higher the value the higher the concentration of OH-.

Now let’s solve the question at hand.

1 is wrong

Water is termed neutral with an average balance of the two ions. pH 9 means higher OH- which stipulates lesser H+ than water.

2 is correct

The pH is termed alkaline and has more hydroxide concentration than water.

3 is wrong

It should have a higher concentration of OH- than water

4 is wrong

It should have a higher acidity and lesser alkalinity. This translates to higher H+ and lower OH- relative to water

Blue-green algae are prokaryotes that carry out photosynthesis in chloroplasts, converting light energy into carbohydrates by using chlorophyll as a pigment for energy absorption.

Some prokaryotes, such as blue-green algae, are photosynthetic and contain chloroplasts where chlorophyll and other pigments absorb energy from the sun to produce carbohydrates via photosynthesis. The algae, specifically, are among the groups of prokaryotes that are capable of photosynthesis, much like plants. The chloroplasts in these cells function as the site where light energy captured by chlorophyll is converted into chemical energy, which is then used to create carbohydrates from carbon dioxide and water.

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Answer:

3.67 kilograms is the mass of a given ice on the earth's surface.

Explanation:

Weight of an object is the force acting on an object by virtue of its mass.

Weight(W)=[tex]mass(m)\times acceleration(a)[/tex]

We have :

Mass of an ice = m =?

Acceleration due to gravity ,a = [tex]9.8m/s^2[/tex]

Weight of an ice , W= 36.0 N

Putting in the values we get,

[tex]36.0 N=m\times 9.8 g/m^2[/tex]

[tex]m=\frac{36.0 N}{9.8 m/s^2}=3.67 kg[/tex]

3.67 kilograms is the mass of a given ice on the earth's surface.

Answer:

The aerobic cellular respiration of the glucose where glucose is converted to energy via four steps as follows

1. Glycolysis (glucose break down to pyruvic acid)

2. Link reaction

3. Krebs cycle

4. Electron transport chain, or ETC

The four pyruvic acid produces Four ATP, twenty NADH, and four [tex]FADH_{2}[/tex] molecules

Explanation:

When four pyruvic acid enters step two of the aerobic cellular respiration, they are converted by Oxidative decarboxylation into acetyl-CoA, four molecules of NADH and four molecule of CO2 are formed. This process is otherwise called the link reaction or transition  step, because it connects or links the Krebs cycle and glycolysis.

From the chemical reactions involved in cellular respiration of one glucose molecule, from two pyruvic acid molecules we have 2 ATP molecules, 10 NADH molecules, and 2 FADH2 molecules

Hence from four pyruvic acid molecules we have that the acetyl-CoA produced from the four pyruvic acid enters the the Krebs cycle and forms four ATP molecules, twenty NADH molecules, and four [tex]FADH_{2}[/tex] molecules.

In aerobic cellular respiration, four molecules of pyruvic acid will generate a total of four molecules of ATP, sixteen molecules of NADH (four from the conversion to Acetyl CoA, and twelve from the Krebs cycle) and four molecules of FADH2

In aerobic cellular respiration, pyruvic acid is converted into acetyl CoA. One molecule of pyruvic acid generates one molecule of NADH during this conversion so four molecules of pyruvic acid will yield four molecules of NADH. Acetyl CoA then enters the Krebs cycle, for each molecule of Acetyl CoA that goes through the Krebs cycle, three molecules of NADH, one molecule of FADH2, and one molecule of ATP is formed. Therefore, the four molecules of pyruvic acid would end up generating four molecules of ATP, twelve molecules of NADH and four molecules of FADH2 during the Krebs cycle (not including the NADH generated during the conversion to Acetyl CoA).

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Answer:

Therefore the required function is

[tex]C= \frac{5}{9} (F-32)[/tex]

Therefore 25°C=57°F

Explanation:

F denotes temperature of Fahrenheit and C denotes temperature of Celsius.

[tex]\frac{C-0}{100-0} =\frac{F-32}{212-32}[/tex]

[tex]\Rightarrow C= \frac{100}{180} (F-32)[/tex]

[tex]\Rightarrow C= \frac{5}{9} (F-32)[/tex]

Therefore the required function is

[tex]C= \frac{5}{9} (F-32)[/tex]

Putting C=25°C in above equation

[tex]25=\frac{5}{9} (F-32)[/tex]

[tex]\Rightarrow 25 \times \frac{9}{5} = F-32[/tex]

⇒45 =F-32

⇒F=32+45

⇒F=57

Therefore 25°C=57°F

The conversion function from Celsius to Fahrenheit is F = (C × 9/5) + 32. Using this, 25°C is converted to 77°F.

The subject of this question is temperature conversion between Celsius and Fahrenheit scales. To create a conversion function from Celsius to Fahrenheit, we use the relationship that a change of 1°C is equivalent to a change of 1.8°F. Since the freezing point of water is 0°C and 32°F, we can derive the following function for converting temperature from Celsius to Fahrenheit:

F = (C × 9/5) + 32.

Using this function, we can convert 25°C into Fahrenheit as follows:

Therefore, 25°C is equal to 77°F.

Answer:

The density of air at 22 °C and 760 torr is 1.195 KG/m³

Explanation:

The solution to the above  question is arrived t by considering the given variables and calculating the number of moles in a 1 m³ sample of air by plugging values into the universal gas equation  from which the number of moles of the constituent gases can be calculated by Dalton's law of partial pressure, then their masses and lastly the density of air is calculated using the formula, Density = mass/volume

The given variables are

Percentage Nitrogen = 78.1% by volume

Percentage oxygen = 20.9% by volume

Percentage argon = 0.934% by volume

The molar mass of nitrogen = 14.006g/mol

The molar mass of oxygen = 15.999g/mol

The molar mass of argon = 39.948 g/mol hence Considering a unit volume of air of one cubic meter (1m^3) we have

0.781 m³ of nitrogen, 0.209 m³ of oxygen and 0.00934 m³ of argon

The number of moles in 1 m³ of gas at 22 °C and 760 torr is given by

PV = nRT or n = [tex]\frac{PV}{RT}[/tex] = where 760 torr = 101325Pa we have n = [tex]\frac{(101325)(0.001)}{(8.314)(295.15)}[/tex] = 0.00413 mols per liter or 41.29 moles/m³

thus we have number of moles of nitrogen = 42.129 × 78.1% = 32.25 moles and the mass of nitrogen = 32.25×28.02 = 903.6 g

number of moles of oxygen= 42.129 × 20.1% = 8.63 moles and the mass of nitrogen = 8.63×32 = 276.16 g

number of moles of argon= 42.129 × 0.934% = 0.386 moles and the mass of nitrogen = 0.386×40 = 15.43 g

Therefore, mass of one cubic meter of air (1 m³), has a mass of

903.6 g + 276.16 g + 15.43 g = 1195.2 g or 1.195 KG Hence the density of air

is given by Density = [tex]\frac{mass}{volume}[/tex] =[tex]\frac{1.195 KG}{1 m^{3} }[/tex]  = 1.195 KG/m³

The density of air at 22 °C and 760 Torr is 1.19 g/L.

Air is 78.1% nitrogen, 20.9% oxygen, and 0.934% argon by moles. We will calculate the average molar mass of the air (M) as a weighted average of the molar masses of its constituents.

[tex]M = 78.1\% \times M(N_2) + 20.9\% \times M(O_2) + 0.934\% \times M(Ar)\\\\M = 78.1\% \times 28.00g/mol + 20.9\% \times 32.00g/mol + 0.934\% \times 39.95 g/mol = 28.93 g/mol[/tex]

Then, we will convert 22 °C to Kelvin using the following expression.

[tex]K = \° C + 273.15 = 22\° C + 273.15 = 295 K[/tex]

Assuming ideal behavior, we can calculate the density (ρ) of the air at 295 K (T) and 760 Torr (P) using the following expression.

[tex]\rho = \frac{P \times M }{R \times T} = \frac{760 Torr \times 28.93g/mol }{(62.4mmHg.L/mol.K) \times 295K} = 1.19 g/L[/tex]

where,

The density of air at 22 °C and 760 Torr is 1.19 g/L.

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Answer:

N2 element, pure substance

O2 element, pure substance

N2O Compound, pure substance

Air  (mostly N2 and O2 ) homogeneous mixture

Explanation:

N2, Nitrogen is known as the chemical element that is characterized by having atomic number 7 and that is symbolized by the letter N, in its molecular version, it is recognized as N2.

O2, Oxygen is the chemical element of atomic number 8, this molecular form is composed of two atoms of this element.

A chemical element is a type of matter, consisting of atoms of the same class.

N2O, Nitrous oxide is formed by the union of two molecules of nitrogen and one of oxygen, which is considered a chemical compound since it is a substance formed by the chemical combination of two different elements of the periodic table.

A pure substance is one that cannot change state or divide into other substances, except for a chemical reaction.

Air (mostly N2 and O2 ),  it is a homogeneous mixture of gases that constitutes the earth's atmosphere. A homogeneous mixture is a type of mixture in which its components are not distinguished and in which the composition is uniform and each part of the solution has the same properties.

Substances can be classified based on their composition and uniformity: N2 and O2 are elements and pure substances, N2O is a compound and a pure substance, and air is a homogeneous mixture or solution.

When classifying substances, we take into account their composition and uniformity. Here are the classifications for the mentioned substances:

N2 (Nitrogen) is an element and a pure substance since it is composed of only one type of atom.

O2 (Oxygen) is also an element and a pure substance, with two oxygen atoms bonded together.

N2O (Nitrous Oxide) is a compound as it is made up of two different elements, nitrogen and oxygen, in a fixed ratio and a pure substance due to its uniform composition.

Air, which is mostly made up of Nitrogen (N2) and Oxygen (O2), is a homogeneous mixture or solution because the composition is uniform throughout, and it is a mixture of multiple gases.

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Answer:

Value of n in MnSO₄.nH₂O is one.

Explanation:

The n represents the number of moles of water attached to the formula unit manganese sulfate. These moles (n) can be determined by taking the ratio of the moles of anhydrous salt and the moles of water. The moles of water can be determined by taking the difference of final and initial mass of the salt. This difference is equal to the mass of the water, mathematically it can be represented as,

Mass of H₂O = initial mass of the salt (g) - final mass of the salt (g)

Mass of H₂O = 16.260 g - 14.527 g

Mass of H₂O = 1.733 g

moles of H₂O = (1.733 g) ÷ (18.015 g/mole)

moles of H₂O =  0.0962

For the moles of anhydrous salt:

moles of MnSO₄ = mass of MnSO₄ ÷ molar mass of MnSO₄

moles of MnSO₄ = 14.5277 ÷ 151.001

moles of MnSO₄= 0.0962

Now for n:

n = moles of water ÷ moles of MnSO₄

n = 0.0962 ÷ 0.0962

n = 1

The above calculations show that one mole of H₂O is attached to the  one formula unit of MnSO₄

Final answer:

To calculate the value of n in the hydrate formula MnSO₄ .nH₂O, the mass of water driven off by heating is found to be 1.733 g. This corresponds to 0.0962 mol of water. Since the ratio of water to MnSO₄is 1:1, n is determined to be 1.

Explanation:

To calculate the value of n in the hydrate formula MnSO₄ . H₂O, we need to find the number of moles of water lost upon heating. We subtract the mass of the anhydrous salt (14.527 g) from the original mass of the hydrate (16.260 g) to get the mass of water lost:

Mass of H₂O = 16.260 g - 14.527 g = 1.733 g

Next, we calculate the number of moles of water using its molar mass (18.015 g/mol):

Number of moles of H₂O = 1.733 g / 18.015 g/mol ≈ 0.0962 mol

To find the number of moles of MnSO₄ in the anhydrous sample, we need its molar mass, which is approximately 151.00 g/mol for MnSO₄. Using the mass of the anhydrous salt:

Number of moles of MnSO₄ = 14.527 g / 151.00 g/mol ≈ 0.0962 mol

This indicates that the mole ratio of H₂O to MnSO₄ is 1:1. Therefore, the value of n is 1, and the hydrate is MnSO₄.H₂O.

Answer:

[tex]\Delta H=2592.825\ J[/tex]

Explanation:

The expression for the calculation of the enthalpy change of a process is shown below as:-

[tex]\Delta H=m\times C\times \Delta T[/tex]

Where,  

[tex]\Delta H[/tex]  is the enthalpy change

m is the mass

C is the specific heat capacity

[tex]\Delta T[/tex]  is the temperature change

Thus, given that:-

Mass of object = 36.2 g

Specific heat = 12.5 J/g°C

[tex]\Delta T=5.73\ ^0C[/tex]

So,  

[tex]\Delta H=36.2\times 12.5\times 5.73\ J=2592.825\ J[/tex]

[tex]\Delta H=2592.825\ J[/tex]

Answer:71.625J

Explanation:Energy(Q)=mCpT

But recall that they said heat capacity (C), not specific heat capacity(cp)....Heat capacity=Mass *cp,but the heat capacity was clearly given so the mass is irrelevant in this case.

Energy (Q)=Heat capacity*Temperature change

Energy=12.5*5.73=71.625J

Answer:

The yeast respired aerobically

Explanation:

The expectation here was that the yeast was going to put the sugar in the grape juice through fermentation, which is an anaerobic process that results in alcohol as one of the products. However since no alcohol was found in this particular example, it is fair to assume that maybe there was oxygen in teh muxture and therefore the yeast respired aerobically, producing water and carbon dioxide as products.

Answer:

The answer to your question is letter C. 21900.3. My result was 21945 J, letter C is close to this result.

Explanation:

Data

mass = 150 g

temperature 1 = T1 = 10°C

temperature 2 = T2 = 45°C

Cw = 4.18 J/g°C

Formula

Q = mCΔT = mC(T2 - T1)

Substitution

Q = (150)(4.18)(45 - 10)

Simplification

Q = (150)(4.18)(35)

Result

Q = 21945 J

Answer:The isotope is Carbon-12 and its atomic mass is 12.

Explanation:

Mass number is the total number of protons and neutrons in a nucleus.

Atomic number is the number of protons in the nucleus of an atom.

An isotope of a chemical element is an atom that has a different mass number but the same atomic number as the element. The difference in mass number is from the number of neutrons (that is, a greater or lesser atomic mass) than the standard for that element.

Carbon-12 is an isotope of carbon it has 6 neutrons and 6 protons, giving it a mass number of 12 and atomic number of 6. Carbon-12 is a stable isotope of carbon, it has the same mass number and atomic number as carbon.

The isotope of carbon that has exactly the same mass and atomic number as used in the definition of the atomic mass unit is;

Isotope Carbon-12.

In chemistry, we know that;

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Answer:

The given chemical compound has 2 atoms of hydrogen and one atom of oxygen for each atom of carbon. The mass of CH2O is 12 + 2*1 + 16 = 30. The molecular weight of the compound is 180.18 which is approximately 180. This gives the molecular formula of the chemical compound as C6H12O6.

Explanation:

To calculate the percent composition of CH2O, determine the molar mass of each element and the total molar mass of the compound. The percent composition is approximately 40.0% Carbon, 6.7% Hydrogen, and 53.3% Oxygen.

To calculate the percent composition of CH2O, we will need to determine the molar mass of each element in the compound and the total molar mass of the compound. The molar masses from the periodic table are approximately 12.01 g/mol for Carbon (C), 1.01 g/mol for Hydrogen (H), and 16.00 g/mol for Oxygen (O).

First, let's calculate the total molar mass of CH2O: (1 × 12.01) + (2 × 1.01) + (1 × 16.00) = 12.01 + 2.02 + 16.00 = 30.03 g/mol.

Now, let's find the percent composition for each element:

The percent composition of CH2O is therefore approximately 40.0% Carbon, 6.7% Hydrogen, and 53.3% Oxygen.

Answer:

The answers to the question are as follows

First part

The mass of PbO2 (s) reduced at the cathode during the period is = 467.55_g

Second part

The electrical charge are transferred from Pb to PbO2 is 377186.86_C or 3.909 F  

Explanation:

To solve this, we write the equation for the discharge of the lead acid battery as

H₂SO₄ → H⁺ + HSO₄⁻

Pb (s) + HSO⁻₄ → PbSO₄ + H⁺ + 2e⁻

at the cathode we have

PbO₂ + 3H⁺ + HSO⁻₄ + 2e⁻ → PbSO₄ + 2H₂O

Summing the two equation or the total equation for discharge is

Pb (s) + PbO₂ + 2H₂SO₄ → 2PbSO₄ + 2H₂O

From the above one mole of lead and one mole of PbO₂  are consumed simultaneously hence

Number of moles of lead contained in 405 g of Pb with molar mass  = 207.2 g/mole = (405 g)/ (207.2 g/mole) = 1.95 mole of Pb

Hence number of moles of  PbO₂ reduced at the cathode = 1.95 mole

mass of  PbO₂ reduced at the cathode = (number of moles)×(molar mass)

= 1.95 mole × 239.2 g/mol = 467.55 g of Lead (IV) Oxide is reduced at the cathode

Part B

Each mole of Pb transfers 2e⁻ or 2 electrons, therefore 1.95 moles of Pb will transfer 2 × 1.95 = 3.909 moles of electrons transferred

Each electron carries a charge equal to -1.602 × 10⁻¹⁹ C or one mole of electrons carry a charge equal to 96,485.33 coulombs

hence 3.909 moles carries a charge = 3.909 × 96,485.33 coulombs =377186.86 Coulombs of electrical charge

or transferred electrical charge = 377186.86 C or 3.909 Faraday

Answer:

Explanation:

A) Moles Pb = [tex]\frac{405 g}{207.2 g/mol}[/tex]

[tex]= 1.95[/tex]

Moles Pb = moles [tex]PbO_2[/tex] reduced

Molar mass [tex]PbO_2 = 239.19 g/mol[/tex]

Grams [tex]PbO_2 = 1.95 mol * 239.19 g/mol[/tex]

[tex]= 466.42g[/tex]

B) 1 mol [tex]PbO_2[/tex] -------------------> 2 F electricity

1 .95 mol [tex]PbO_2[/tex] --------------> 2 * 1.95 F electricity = [tex]3.9F[/tex]

number of coulombs = [tex]3.9 * 96485C[/tex]

[tex]= 3.76*10^5C[/tex]

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Answer: Both (a) and (b)

Explanation:

Lipids are heterogeneous group of compounds of biochemical importance. Lipids may be defined as compounds which are relatively insoluble in water and are concentrated of energy source.

Fatty acids are aliphatic carboxylic acids and have the general formula, R-COOH, where COOH is the functional group and R group are hydrocarbon chain.

The structure of fat contains lot of C-C and C-H bonds and there are lot of calories, and therefore energy is packed into thier chemical structure.

Despite fat contains glycerol polar group, the long chains of hydrocarbon which are non polar makes fats insoluble in water.

Answer:

Both (a) and (b)

(a) rich in energy.

(b) insoluble in water.

Explanation:

Fats are stored as triesters (triglycerides), which when hydrolyzed form the three alcohol molecules (triglycerol) and three fatty acids. The acids that are liberated usually have long carbon chains that contain anywhere from 4 to 18 carbons. The C-C and C-H have high electron molecules present hence whey they are good sources of energy.

However, the bonding between carbon (C-C) and hydrogen (C-H) are not polar. This is because the electrons in covalent bonds are shared equally between the carbon and the hydrogen (due to their similar electronegative values) and there are no partial charges. Thus, long chains of C-C and C-H bonds form fats.

Explanation:

Conservation of momentum :

[tex]m_1u_1+m_2u_2=m_1v_1+m_1v_2[/tex]

Where :

[tex]m_1, m_2[/tex] = masses of object collided

[tex]u_1,u_2[/tex] = initial velocity before collision

[tex]v_1,v_2[/tex] = final velocity after collision

We have :

Mass of an engine = [tex]m_1=4M[/tex]

Mass of an car= [tex]m_2=M[/tex]

Initial velocity of railroad engine [tex]m_1=u_1=5 km/h[/tex]

Initial velocity of car [tex]m_2=u_2=0 km/h[/tex] (rest)

Final velocity of  railroad engine [tex]m_1=v_1=v[/tex] (same direction )

Final velocity of car [tex]m_2=v_2=v[/tex] (same direction)

[tex]4M\times 5km/h+M(0 km/h)=4Mv+Mv[/tex]

[tex]4\times 5 km/h=5M[/tex]

v = 4 km/h

The speed of the engine and car after they coupled together is 4 km/h.

Using the principle of conservation of momentum, it's shown that the diesel engine and freight car will coast together at 4 km/h after coupling. This is calculated by equating the initial and final momentums of the system.

The conservation of momentum can be used to solve this problem. The principle states that the total linear momentum of a closed system remains constant, regardless of any internal changes. Here, the system consists of the diesel engine and the freight car.

Let's denote the weight of the freight car as 'm'. Given that the diesel engine weighs four times as much as a freight car, the weight of the engine would be '4m'.

If the diesel engine is coasting at 5 km/hr, the initial momentum of the system is the momentum of the engine, because the freight car is at rest. Therefore, the initial momentum (Pi) is the weight of the engine times its velocity, which is 4m*5 km/hr = 20m km/hr.

After they couple together, there's no external force, so the total momentum should remain the same (the conservation of momentum principle). Let's denote the final velocity of the engine + car (now moving together) as 'v'. The final momentum (Pf) = (m + 4m) * v = 20m km/hr.

Therefore, we can establish the equation: Pi = Pf, meaning 20m km/hr = 5m * v. Solving for v, we find that v = 4 km/h. Therefore, the engine + car coast together at 4 km/h after coupling, demonstrating the conservation of momentum.

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A sigma bond b. overlap of two d orbitals end-to-end overlap of p orbital.

A sigma bond is a strong bond that is made up of overlapping orbitals. In fact, these bonds are the strongest known bonds in chemical reactions. The overlapping orbitals are in the form of covalent bonding and this gives us the idea that sigma bonds are strong in nature.

In addition, sigma bonds are mostly common with diatomic elements and compounds. There are three orbitals where the sigma bond can be found and they are the p-p, s-p, and the s-s orbitals. These are known for forming symmetry groups.

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Answer:

The events of Bruno seeing the young boy in the concentration camp, slowly seeing his father’s evil side come out, and having his sister explain to him what was really happening; all lead Bruno to gradually see what was really going on.

Explanation:

Answer:

1.8 atm

Explanation:

As temperature and moles of a gas reamin both constant, we can say that:

Pressure₁ . Volume₁ = Pressure₂ . Volume₂

1.20 atm . 600 mL = Pressure₂ . 400 mL

(1.20 atm . 600 mL) / 400 mL = Pressure ₂ → 1.8 atm

Answer : The intensity of sound level in decibels is, 169 dB

Explanation:

The expression used for the intensity of sound level is given by the equation:

[tex]P=10\times \log \frac{I}{I_o}[/tex]

where,

I = final intensity = [tex]7.53\times 10^4W/m^2[/tex]

[tex]I_o[/tex] = initial intensity = threshold intensity of human hearing = [tex]10^{-12}W/m^2[/tex]

Now put all the given values in the above formula, we get:

[tex]P=10\times \log \frac{7.53\times 10^4W/m^2}{10^{-12}W/m^2}[/tex]

[tex]P=168.767dB\approx 169dB[/tex]

Thus, the intensity of sound level in decibels is, 169 dB

Final answer:

The sound intensity level in decibels of the ultrasound used to pulverize tissue during surgery is 160 dB.

Explanation:

The sound intensity level in decibels (dB) of ultrasound with an intensity of 7.53 × 10^4 W/m² used to pulverize tissue during surgery can be calculated using the formula:

IdB = 10 log10 (I/I0)

where I is the given intensity (7.53 × 10^4 W/m²) and I0 is the reference intensity (10^-12 W/m²).

Using the formula:

IdB = 10 log10 (7.53 × 10^4 / 10^-12)

We can calculate:

IdB = 10 log10 (7.53 × 10^16)

IdB = 10 × 16 (using log10 (ab) = b × log10 (a))

IdB = 160 dB

Therefore, the sound intensity level in decibels of the given ultrasound is 160 dB.

Answer:

The mass of water did Doc placed in the bottle is 288 grams.

Explanation:

Mass of water filled in water bottle = M

Volume of the water filled in water bottle = V = 288 mL

Density of the water at 20°C , d= 0.99823 g/ml

[tex]D=\frac{M}{V}[/tex]

[tex]M=D\times V=0.99823 g/ml\times 288 mL=287.49024 g\approx 288 g[/tex]

The mass of water did Doc placed in the bottle is 288 grams.

Final answer:

The mass of water at 20 °C with a density of 0.99823 g/mL that Doc placed in the bottle is 287 g when rounded to three significant digits.

Explanation:

The mass of water Doc placed in the bottle can be calculated using the density of liquid water at 20 °C, which is 0.99823 g/mL. Given he filled it with exactly 288 mL of water, the mass of the water is calculated by multiplying the volume by the density: The mass of water at 20 °C with a density of 0.99823 g/mL that Doc placed in the bottle is 287 g when rounded to three significant digits.

Mass = volume × density

Mass = 288 mL × 0.99823 g/mL

Mass = 287.63064 g

Since we are asked to provide the mass to three significant digits, the mass of water Doc placed in the bottle is 287 g.