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The number of molecules of water in a 45 g sample of H2O is approximately 3.7 x 10^24 molecules H2O.

To calculate the number of molecules, we need to use Avogadro's number, which states that there are 6.022 x 10^23 molecules in one mole of a substance. First, we need to determine the number of moles of water in the 45 g sample. The molar mass of water (H2O) is approximately 18 g/mol (2 g/mol for hydrogen and 16 g/mol for oxygen).

Using the formula:

moles = mass / molar mass

moles = 45 g / 18 g/mol

moles = 2.5 mol

Now, to find the number of molecules, we multiply the number of moles by Avogadro's number:

number of molecules = moles * Avogadro's number

number of molecules = 2.5 mol * (6.022 x 10^23 molecules/mol)

number of molecules = 3.7 x 10^24 molecules

Therefore, there are approximately 3.7 x 10^24 molecules of water in a 45 g sample of H2O.

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Why it is important to have balanced charges when forming ionic compounds?

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The correct answer is (D). Oxidation occurs when there is an increase in the number of carbon-oxygen bonds.

Oxidation is the loss of electrons or an increase in the oxidation state of an atom, molecule, or ion. It occurs when oxygen atoms are added to another molecule and creates a new bond between the oxygen atom and the other atom, resulting in an increase in the number of carbon-oxygen bonds.

Antoine Lavoisier used the term "oxidation" to describe the reaction of a material with oxygen. The meaning was later expanded to cover additional reactions in which electrons are lost, regardless of whether oxygen was present, after it was realised that the substance loses electrons when it is oxidised.

Therefore the correct alternative is: 'Oxidation occurs when there is an increase in the number of carbon-oxygen bonds.'

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Explanation:

The "Roman numeral notation" uses symbols to indicate how large the positive charge of the metal ion is.

In particular:

A charge of 1+ is labeled with a capital (I),

2+ is labeled with a capital (II),

3+ is labeled with a capital (III),

4+ is (IV)

5+ is (V)

6+ is (VI)

7+ is (VII)

So, in our question, we have Cu^1+. The element symbol "Cu" is copper, and we have a 1+ charge. The Roman numeral notation is: Copper (I)

For the second part, we have CoCl2. The metal here is Co. The element symbol "Co" is cobalt. What is the charge? We should know that Cl has a negative charge of 1-, so since we have two Cl atoms, the overall negative charge is 2-. Since the substance is neutral, this means that the cobalt atom must have a positive charge of 2+ to balance. So, the Roman numeral notation is: Cobalt (II)

Answer:

Hey there sweetsgibbs

Explanation:

Exercise 1:

When standing with one foot on a rug and the other foot on a tile, linoleum, or wood floor, the foot on the tile, linoleum, or wood floor usually feels colder. However, the temperature of both surfaces is the same. This is because materials have different abilities to conduct heat, which affects the rate at which heat is transferred from the body to the material. Tile, linoleum, and wood are better conductors of heat than rugs, which means they transfer heat away from the body more quickly, giving the sensation of being colder. The rug, on the other hand, is a poor conductor of heat and insulates the foot, reducing the rate of heat transfer and giving the sensation of being warmer.

Exercise 2:

When placing one ice cube on a metal pan and the other on a plate with a folded paper towel under it, the ice cube on the metal pan usually melts faster. This is because metals are better conductors of heat than ceramics, which means they transfer heat away from the ice cube more quickly. The paper towel underneath the ice cube on the plate may also absorb some of the water as it melts, which can slow down the melting process slightly.

Answer:

answer above is right! thank you to them muah

Explanation:

Answer:

0.225M

Explanation:

Equation: M=n/v

n = moles of solute

v = liters of solution

NaCl = 58.443 g/mol

16.88/58.443= 0.289 moles of NaCl

0.289/1.283=0.225M

14,400 gallons of water can be filtered by the new water filter invented by the company.

It is given that the filter can process 10 gallons of water per minute.

So In an hour:

10 gallons per minute x 60 minutes = 600 gallons in 1 hour.

And in a day:

24 hours x 600 gallons per hour = 14,400 gallons in 24 hours.

Hence, 14,400 gallons of water can be filtered.

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To calculate the mass percent of the phenol in the solution, we first need to calculate the total mass of the solution.

The total mass of the solution can be calculated by multiplying the density of phenol (1.070 g/ml) by the volume of phenol (400.0 ml), and adding this to the mass of the water (1217.9 ml x 1.000 g/ml).

This gives us a total mass of the solution of 506.77 g.

To calculate the mass percent of the phenol in the solution, we need to divide the mass of phenol by the total mass of the solution and multiply this by 100.

The mass of phenol is 400.0 ml x 1.070 g/ml, which equals 427.8 g. The mass percent of the phenol is 427.8 g/506.77 g x 100 = 84.3%.

In conclusion, the mass percent of the phenol in the solution is 84.3%.

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Elements that obey the octet rule must have exactly 8 electrons in their outermost energy level, which is also called the valence shell.

The octet rule is a chemical rule that states that atoms tend to combine in such a way as to have eight electrons in their valence shell, which makes them stable. Elements in group 8A or 18, also known as the noble gases, already have a full valence shell of 8 electrons, making them very stable and unreactive. Other elements such as carbon, nitrogen, oxygen, and fluorine tend to follow the octet rule by either gaining or losing electrons or by sharing electrons with other atoms in order to achieve a full valence shell of 8 electrons. However, there are exceptions to the octet rule such as molecules with an odd number of electrons or with atoms that can accommodate more than 8 electrons in their valence shell.

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The cart starts out in position A with high potential energy, low kinetic energy, and some thermal energy. As the cart progresses into position B, the kinetic energy begins to increase and the potential energy begins to decrease; as the thermal energy increases as thermal energy from the track is transferred to the cart through friction. Once the cart reaches position C, it has high kinetic energy, low potential energy, and some thermal energy. At position D, the cart has high potential energy, low kinetic energy, and some thermal energy. The potential energy throughout is correlated to gravity, the kinetic energy is correlated to momentum, and the thermal energy is correlated to friction. The potential energy is at its maximum during position A, and its minimum at position C; the kinetic energy is at its maximum during position C, and its minimum at position A; the thermal energy is at its maximum during position B, and its minimum at position A

Answer:

C) A covalent bond formed with an unequal sharing of electrons

Explanation:

A polar covalent bond is the unequal sharing of electrons in a covalent bond

Answer:

Explanation: l m n o p q r s t u v w x y z

A medical assistant should use Povidone iodine while performing surgical skin preparation instead of other given solutions.

Antiseptics are chemicals that, although not necessarily killing bacteria, stop their growth and development in a variety of situations. These chemical compounds are typically replaced by phenolic compounds. Triclosan is a frequently used antiseptic chemical that disrupts cell membranes as a general mode of action. Chlorhexidine, povidone-iodine, chloroxylenol, isopropyl alcohol, hexachlorophene, benzalkonium chloride, and hydrogen peroxide are typical antiseptics used in dermatologic surgery. They should be utilized for the majority of treatments that go deeper than the epidermis of the skin.

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Answer:

The amount of energy produced is less than 454 kJ.

Explanation:

I do not know but if am wrong you can correct me. I need your help for business, english and chemistry questions on my profile. So can you and the other person who commented and go on my profile please...? the due date already gone 12 days ago.

Based on the given data, the correct arrangement of activities in decreasing order of their contribution to climate change is: D-C-E-B-A

Explanation:

The pie chart provides information on US sources of greenhouse gas emissions by economic sector in 2013. To arrange the activities in decreasing order of their contribution to climate change, we need to consider the sectors with the highest percentages of emissions.

D - Electricity generation and heat production (largest sector)

C - Transportation

E - Industrial processes

B - Commercial and residential

A - Agriculture

Therefore, the correct arrangement is D-C-E-B-A.

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Put a 2 in front of H2O to balance the hydrogen atoms: CH4 + O2 CO2 + 2H2O. The oxygen atoms can be balanced by adding a 2 before the O2 on the left: CH4 + 2O2 CO2 + 2H2O.

Methane (CH4) combines with oxygen to produce carbon dioxide and water. This kind of combustion reaction is taking place. When a substance combines with oxygen molecules, it is called a combustion reaction. The balanced equation is 2CO+O22CO2. The equation is now in equilibrium.In a combustion reaction, a hydrocarbon (a substance containing carbon, hydrogen, and perhaps oxygen) always interacts with oxygen to produce carbon dioxide and water.

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The value of rate constant is  3.33 x 10^-11 cm3/molecules-s. To determine the order of the reaction with respect to oxygen atoms, we can use the data collected in the first set of experiments.

Where NO2 was in large excess. We can use the method of initial rates, where we compare the rates of the reaction at different initial concentrations of O.  From the data, we can see that

at t = 1.0 x 10^-2 s, [O] = 1.9 x 10^9 atoms/cm3 and

the rate is k[O]^x[NO2]

, where x is the order of the reaction with respect to O.

At t = 2.0 x 10^-2 s,

[O] = 6.8 x 10^8 atoms/cm3 and

the rate is k[O]^x[NO2].

At t = 3.0 x 10^-2 s,

[O] = 2.5 x 10^8 atoms/cm3 and

the rate is k[O]^x[NO2].

Since the order of the reaction with respect to O is x. for

(b), the reaction is known to be first order with respect to NO2,

so the overall rate law is rate = k[NO2].

To determine the value of the rate constant, we can use the integrated rate law, which is -[O] = kt + [O]0,

Where [O] is the concentration of O at time t,

k is the rate constant and

[O]0 is the initial concentration of O.

Using the data from the first experiment

where t = 3.0 x 10^-2 s and

O] = 2.5 x 10^8 atoms/cm3,

the value of k. -2.5 x 10^8 = k * 3 x 10^-2 + 5 x 10^9.

Solving for k, we get k = 3.33 x 10^-11 cm3/molecules-s.

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According to the stoichiometry of the given balanced chemical equation, 13.5 moles of propane  are needed to make 13.5 moles of carbon dioxide.

Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.

A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .

The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.

As per stoichiometry, 1 mole propane gives 3 moles carbon dioxide thus 13.5 moles of carbon dioxide will require 1×13.5/3=4.5 moles.

Thus, 13.5 moles of propane  are needed to make 13.5 moles of carbon dioxide.

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Answer:

temperature of a metal is29.8

temp. of water is 6.2

temp. change of metal -40.6

Explanation:

Answer:

q = mC∆T

q = heat = ?

m = mass = 6.30 g

C = specific heat = 0.385 J/g/deg

∆T = change in temperature = 32-20 = 12º

q = ((6.30 g)(0.385 J/g/deg)(12 deg) = 29.1 J (to 3 significant figures)

Explanation:

The classification of controlled substances that contains drugs with a high potential for abuse and addiction, but are approved for medical use is Schedule II.

The Drug Enforcement Administration (DEA) has five classifications, or schedules, for controlled substances based on their potential for abuse, medical use, and safety. Schedule II substances have a high potential for abuse and may lead to severe psychological or physical dependence, but they also have a currently accepted medical use in the United States with severe restrictions.

Examples of Schedule II substances include opioids such as fentanyl, oxycodone, and hydrocodone, as well as stimulants such as amphetamine and methylphenidate. These substances require a written or electronic prescription and cannot be refilled without a new prescription from a doctor.

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In this example, the exam, Carlos concerns, and his behavior may be seen as an example of eustress.

Stress is a normal physiological and psychological reaction that people have in response to their surroundings. Eustress refers to positive, motivating stress that improves functioning, whereas distress refers to negative, overwhelming stress that impairs functioning.

Eustress refers to positive stress, which can be psychological, physical, or biochemical/radiological. Endocrinologist Hans Selye coined the term, which combines the Greek prefix eu-, which means "good," and stress, which literally means "good stress." Eustress refers to beneficial stress, which can be psychological, physical, or biochemical/radiological in nature.

Since Carlos has a comprehensive final exam in three weeks that he is concerned about and this made him to go ahead and start studying, this is eustress.

Exhilarating rides, competition, and a good scary movie are all examples of Eustress.

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Complete question

Carlos has a comprehensive final exam in three weeks that he is concerned about. His concerns prompt him to go ahead and start studying and in doing so, he feels less worried as the exam approaches. In this example, the exam, Carlos concerns, and his behavior may be seen as an example of ?

Answer:

the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.

Explanation:

basically when plants make food for themselves

Answer:

Explanation:

The use of coal combustion fly ash in concrete can have both positive and negative effects on the mass transport release of constituents of potential concern.

On the positive side, the inclusion of fly ash can enhance the durability and strength of concrete. Fly ash is a pozzolanic material that can react with calcium hydroxide to form additional cementitious compounds, resulting in a denser and more impermeable concrete matrix. This can reduce the diffusion of harmful substances, such as chlorides and sulfates, and limit their potential for mass transport.

However, the effect of fly ash on the release of constituents of concern depends on several factors. The composition of the fly ash, including its chemical and mineralogical properties, can influence the leaching behavior of certain elements. Additionally, the presence of certain contaminants in the fly ash, such as heavy metals, can potentially leach into the surrounding environment.

Thus the use of coal combustion fly ash in concrete can have both positive and negative effects on the mass transport release of constituents of potential concern.

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Answer:

1)NUCLEUS -> It is the center of an atom which contain protons and neutrons

SHELL-> the space where the probability of finding electrons is maximum in the atom is known as shell

there are mainly four shells KLMN

2)NUCLEUS->The average potential of Nuclei is different from that of an atom.

SHELL -> The average Potential varies.

3)NUCLEUS ->Particles of the shell structure of nuclei are neutrons and protons

SHELL->Particles of the shell structure of an atom are electrons

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Answer:

Speed

Explanation:

Aliyah must have been trying to find her speed.

The speed is a measure of how fast an object or a body is and it is calculated by finding the ratio of distance with time. Mathematically,

  speed = \(\frac{distance}{time}\) with a unit of m/s.

Hence, with the distance measured on the ground and Aliyah trying to find the time it will take her to cover the distance while running, she must have been trying to find how fast she can run, that is, speed.

To determine the mass of carbon dioxide produced in the reaction, we need to use the balanced chemical equation. The balanced equation for reaction A is:

2 Fe2O3 + 3 C -> 4 Fe + 3 CO2

The reaction tells us that for every 2 moles of Fe2O3, 3 moles of CO2 are produced. We are given the amount of Fe produced, which is 12 moles, so we can use that to determine the amount of Fe2O3 consumed and, therefore, the amount of CO2 produced.

First, let's calculate the amount of Fe2O3 consumed:

12 moles Fe / (4 moles Fe / 2 moles Fe2O3) = 6 moles Fe2O3

Next, we can use the ratio of Fe2O3 to CO2 from the balanced equation to calculate the amount of CO2 produced:

6 moles Fe2O3 * (3 moles CO2 / 2 moles Fe2O3) = 9 moles CO2

Finally, to convert moles to grams, we use the molar mass of CO2, which is 44.01 g/mol:

9 moles CO2 * 44.01 g/mol = 396.09 g CO2

In the electrolysis of molten magnesium chloride;

a. the half reactions are as follows:

Reduction half reaction: Mg²⁺ + 2 e⁻ → Mg (s)

Oxidation half reaction: 2 Cl (aq) →  Cl₂ (g)

b. magnesium ion is reduced whereas chloride ion is oxidized.

c The minimum voltage required to separate magnesium chloride into its elements is 386000 C of electricity.

Electrolysis is the decomposition of a substance known as an electrolyte when an electric current is passed through a solution or molten form of the substance.

During electrolysis, oxidation and reduction reactions occur that can be split into half equations.

In the electrolysis of molten magnesium chloride, the overall reaction is given below:

MgCl₂ (l) → Mg (s) + Cl₂(g)

a. The half reactions are as follows:

Reduction half reaction: Mg²⁺ + 2 e⁻ → Mg (s)

Oxidation half reaction: 2 Cl (aq) →  Cl₂ (g)

b. Based on the half equations given above, the magnesium ion is reduced as it accepts two electrons to become a neutral magnesium atom. Chloride ion is oxidized as two chloride ions lose two electrons to become chlorine gas.

c The minimum voltage required to separate magnesium chloride into its elements is determined from the moles of electrons involved in the reaction.

Magnesium ion and chloride ions require two moles of electrons each to become the neutral element. Thus, 4 moles of electrons are required.

4 moles of electrons = 4 * 96500 C of electricity

4 moles of electrons = 386000 C of electricity.

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