PLEASE HELP 9. 26 g of an unknown solid is dissolved in a coffee cup calorimeter that contains 62. 0 mL of water.

The measured temperature increased from 23. 4 °C to 24. 7 °C. The specific heat of water is 4. 184Jg

10c-1 and assume the density of the solution is 1. 00 g mlº? Calculate the molecular weight of the

unknown solid if the AH was determined to be -2. 51 k) moll via another experiment.

Answer:

20L

Explanation:

The following data were obtained from the question:

Initial volume (V1) = 10L

Initial Temperature (T1) = stp = 273K

Final temperature (T2) = 546K

Final volume (V2) =..?

The new volume of the gas can be obtained by using the Charles' law equation as shown below:

V1/T1 = V2/T2

10/273 = V2/546

Cross multiply to express in linear form

273 x V2 = 10 x 546

Divide both side by 273

V2 = (10 x 546) / 273

V2 = 20L

Therefore, the new volume of the gas is 20L.

The value of b in the equation \(\( f(t) = 85 \cdot b^t \)\) represents the decay factor of the radioactive substance. To determine the value of \( b \), we can use the information that the half-life of the substance is 21 years.

The half-life of a radioactive substance is the time it takes for half of the substance to decay. In this case, the half-life is 21 years, which means that after 21 years, the amount of the substance remaining will be half of the initial amount.

We can use this information to set up an equation:

\(\(\frac{1}{2} = b^{21}\)\)

To solve for b, we need to take the 21st root of both sides of the equation:

\(\(b = \left(\frac{1}{2}\right)^{\frac{1}{21}}\)\)

Using a calculator, we can evaluate this expression:

\(\(b \approx 0.965\)\)

Therefore, the value of b in the equation \(\( f(t) = 85 \cdot b^t \)\) is approximately 0.965.

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The oxidation number of manganese in MnO2 is +4.

To determine the oxidation number of manganese in MnO2, we can use the fact that oxygen has an oxidation number of -2 in this compound. Let's assume the oxidation number of manganese is x.

Since MnO2 is a neutral compound, the sum of the oxidation numbers of all the elements must be zero. We can set up the equation:

x + 2(-2) = 0

Simplifying the equation, we have:

x - 4 = 0

Adding 4 to both sides, we get:

x = 4

Therefore, the oxidation number of manganese in MnO2 is +4.

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The manganese (Mn) oxidation number in \(MnO_2\) is +4.

The idea of ​​oxidation number, commonly referred to as oxidation state, refers in chemistry to the imaginary charge that an atom would have if all of its bonds were exclusively ionic.

By assigning oxidation numbers to other elements and using the axiom that the sum of the oxidation numbers in a compound is zero, it is possible to determine the oxidation number of manganese (Mn) in MnO2 (manganese dioxide).

The general oxidation number of oxygen (O) is 2.

Let the oxidation number of manganese in MnO2 be x.

Thus, we have (-2)*2+x=0.

To simplify the calculations:

-4 + x = 0

x = 4 Adding 4 to both sides.

As a result, the manganese (Mn) oxidation number in \(MnO_2\) is +4.

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Ответ:ответ

.Объяснение:т.к вода это одно вещество и лёд тоже делают из

The answer is (70.35, 84.57) mL.

The three volumes of NaOH required to attain a pH of 7 in each of the three titrations are: 82.16, 75.79, and 75.43 mL. To estimate the mean number of milliliters required to neutralize 1 gram of the acid, a 99 percent confidence interval will be used. Let's calculate the sample mean, sample standard deviation, and margin of error using the provided data.

Sample standard deviation:

Sample Mean The sample mean of a dataset is defined as the sum of all the data points divided by the number of data points. So the sample mean will be: (82.16+75.79+75.43) / 3 = 77.46 mL. Sample Standard Deviation The sample standard deviation (s) is defined as the square root of the sample variance. To calculate s, we need to first compute the sample variance (s²):s² = ∑(x - μ)² / (n - 1)where x is the value of the observation, μ is the sample mean, and n is the sample size.s² = [(82.16 - 77.46)² + (75.79 - 77.46)² + (75.43 - 77.46)²] / (3 - 1)s² = [20.4 + 6.74 + 5.84] / 2s² = 16.49s = sqrt(16.49) = 4.06 mL.

Marginal Error The formula for the margin of error for a confidence interval for the mean is:

margin of error = t (α/2) * (s / sqrt(n)) where t(α/2) is the critical value of the t-distribution with n-1 degrees of freedom and a level of significance of α/2 (in this case, α/2 = 0.005).s is the sample standard deviation that we computed earlier. n is the sample size (in this case, n = 3). margin of error = t(α/2) * (s / sqrt(n))margin of error = 3.182 * (4.06 / sqrt(3)) = 7.11 mL. The margin of error is 7.11 mL. Confidence Interval The confidence interval formula for a population mean is: sample mean - margin of error < μ < sample mean + margin of error where μ is the population mean and sample mean is the value obtained from the sample.μ = 77.46 - 7.11 < μ < 77.46 + 7.11Thus, the 99% confidence interval for the mean number of milliliters needed to neutralize 1 gram of the acid is (70.35, 84.57) mL (rounded to three decimal places).Therefore, the answer is  (70.35, 84.57) mL.

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Answer:

–1647.45 J

Explanation:

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

Mass (M) = 112.5 g

Initial temperature (T₁) = 12.5 °C

Final temperature (T₂) = 9°C

Specific heat capacity (C) = 4.184 J/g°C

Heat (Q) absorbed =?

Next, we shall determine the change in temperature. This can be obtained as follow:

Initial temperature (T₁) = 12.5 °C

Final temperature (T₂) = 9°C

Change in temperature (ΔT) =?

ΔT = T₂ – T₁

ΔT = 9 – 12.5

ΔT = –3.5 °C

Finally, we shall determine the heat absorbed. This can be obtained as follow:

Mass (M) = 112.5 g

Change in temperature (ΔT) = –3.5 °C

Specific heat capacity (C) = 4.184 J/g°C

Heat (Q) absorbed =?

Q = MCΔT

Q = 112.5 × 4.184 × –3.5

Q = –1647.45 J

Answer:

jupiter

Explanation:

mercury, venus, earth, mars, jupiter, saturn, uranus, neptune,

Answer:

[H]

Explanation:

This is nascent hydrogen it's a reactive form of hydrogen...

It reduces elements and compounds.

In modern proteomic analysis, the amino acid sequence of a protein can be determined by methods such as mass spectrometry and Edman degradation.

Proteomics is the large-scale study of proteins, particularly their structures and functions. Determining the amino acid sequence of a protein is a fundamental aspect of proteomics, as it provides important information about the structure and function of the protein. Modern proteomic analysis has several methods for determining the amino acid sequence of a protein.

One such method is mass spectrometry, which involves the ionization and fragmentation of the protein into smaller peptide fragments, and the measurement of the mass-to-charge ratios of these fragments. By analyzing the mass-to-charge ratios of these fragments, the amino acid sequence of the original protein can be reconstructed.

Another method is Edman degradation, which involves the sequential removal of amino acids from the N-terminus of the protein and their identification through chemical reactions. These methods are both widely used in modern proteomic analysis and have greatly advanced our understanding of the structure and function of proteins.

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Answer: C (8 dots)

Explanation:

The electron configuration of an atom refers to the arrangement of electrons in the atom's outermost energy level, or valence shell. An electron configuration of 2-6 refers to a total of 8 electrons in the valence shell, with 2 in the first energy level and 6 in the second.

There are 4,000 parts per million (ppm) of chlorine in the pool.

To calculate the parts per million (ppm) of chlorine in the pool, we can use the formula:

ppm = (part / whole) x 1,000,000

In this case, the part is the amount of chlorine, which is given as 8 g, and the whole is the amount of water, which is 2,000,000 g. Substituting these values into the formula, we get:

ppm = (8 g / 2,000,000 g) x 1,000,000

Simplifying this expression, we find:

ppm = (4 x 10^-6) x 1,000,000

ppm = 4,000

This means that for every one million parts of the pool's water, there are 4,000 parts of chlorine. In other words, the concentration of chlorine in the pool is 4,000 ppm, indicating a relatively high level of chlorine compared to the water.

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The three professional areas that uses metric system are the scientific fields, medical fields, or technical fields.

The metric system is a measurement method that utilizes the meter, liter, as well as gram as base units for length for distance, capacity for volume, and weight for mass.

The primary factors for the United States' failure to embrace the metric system are simply cost and time.

When the country's Industrial Revolution began, expensive manufacturing plants was becoming a major source of American jobs and basic goods.

Thus, the scientific, medical, and technical fields are the three professional fields that use the metric system.

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Answer:

Fred did not tke an A in the exam.

Explanation:

To take an A in the exam, the density of the measurements must be between a 0.500% of 0.7925g/mL. That is:

0.7988g/mL + 0.7988g/mL* (0.5/100) = 0.8028g/mL

0.7988g/mL - 0.7988g/mL* (0.5/100) = 0.7948g/mL

That means to take an A on the lab the desnity determined must be between 0.8028g/mL and 0.7948g/mL

As the density determined was 0.7925g/mL, Fred did not tke an A in the exam

The given statement "PAH is an acronym for polycyclic aromatic hydrogen" is true because it is the Polycyclic Aromatic Hydrocarbons.

The Polycyclic Aromatic Hydrocarbons that is the (PAHs)  are the class of the chemicals that will occur naturally in the coal, crude oil, and the gasoline. They will result from the burning coal, oil, gas, the wood, the garbage, and the tobacco. The PAHs can be bind to or form the small particles in the air.

These compounds are the range from the simple two ring compounds such as the naphthalene and the its derivatives to the more intricate ring structures with the up to the 10 rings.

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Answer:

Five significant figures

Explanation:

You have to change the number to standard form

340500 = 3.405×10**5

** means raise to power

10**5

Where five represents the number of significant figures.

Answer:

4!

Explanation:

Answer:

Does a magnet attract the element?

Explanation:

This is because, the attraction of an element by a magnet is a purely physical property. It has to do with the orientation of the electrons in the element. It does not tell us of the composition of the element or how it reacts with other elements. Whereas, the other questions deal with the chemical properties of the element. That is, how it reacts with other elements or substances.

Naturally occurring metals such as lead or arsenic that affect the nervous system are called Neurotoxins.

These metals are found in the environment either naturally or as a result of human activities such as mining, smelting and industrial processes. Exposure to neurotoxic metals can lead to a range of health problems, particularly in the nervous system. Lead and arsenic are two of the most common neurotoxic metals, and can affect the nervous system in a number of ways.

Lead is known to damage the nerves and brain cells, and can cause learning disabilities, behavioral problems and fatigue. Arsenic can affect the way the nervous system works by interfering with the production of neurotransmitters. It can also cause neurological problems such as reduced coordination and numbness. Both metals can be absorbed through the skin, and can accumulate in the body over time, resulting in more serious neurological problems.

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Answer:

6 g

Explanation:

The balanced equation for the reaction is:

CH4 + 2O2 → CO2 + 2H2O

Using the balanced equation, we can see that 1 mole of CH4 reacts with 2 moles of O2 to produce 1 mole of CO2 and 2 moles of H2O.

We first need to calculate the number of moles of water produced:

20.0 g H2O × (1 mol H2O/18.015 g H2O) = 1.11 mol H2O

Since 1 mole of CH4 produces 1 mole of CO2, we know that the number of moles of CO2 produced is also 1.11 mol.

Now we can use the molar mass of CO2 to convert moles to grams:

1.11 mol CO2 × (44.01 g CO2/1 mol CO2) = 48.85 g CO2

Therefore, the mass of CO2 produced in the reaction is approximately 6 g.

The thing that would happen  to the total amount of energy in the Earth system and to global average temperature if methane in the atmosphere increases is the Increased Energy Trapping and Increased Greenhouse Effect.

Methane reacts in a number of dangerous ways as it is released into the atmosphere. For starters, methane typically exits the atmosphere through oxidation, when it is converted to carbon dioxide and water vapor. Methane, therefore, not only directly but also indirectly through the emission of carbon dioxide, contributes to global warming.

Global warming is the gradual warming of the Earth's surface that has been seen since the pre-industrial era which raises the levels of heat-trapping greenhouse gases in the atmosphere.

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Answer:

the reaction was that it turned green. because it used to be brown but because the rain and carbon dioxide affected it.

Answer:

Nucleus is the brain of the cell and controls most of its functions. Thus without a nucleus, an animal cell or eukaryotic cell will die.

Answer:

A. genetic information will not be transmitted by the cell

Explanation:

There is a way to decrease the concentration of an ion here. The carbonate ion happens to be easy to decrease. All we have to do is add some acid (say HCl) to the container. The following sequence of reactions explains how this WO r ks.

As long as more acid is added, this process will continue until all the solid Zn CO3 has been dissolved

Carbon has four valence electrons, so it can achieve a full outer energy level by forming four covalent bonds. When it bonds only with hydrogen, it forms compounds called hydrocarbons. Carbon can form single, double, or triple covalent bonds with other carbon atoms.

a wrong

b wrong

c right

d wrong

Answer:

An ion with 11 protons, 11 neutrons, and 10 electrons would have a charge of 1+, also expressed as a charge of positive one or +1.

2.55 mol Mg yields 242.89 grams of MgCl2.

Because MgCl2 and Mg have a 1:1 molar ratio, every time 1 mole of Mg interacts, 1 mole of MgCl2 is also created. As a result, the amount of Mg that reacts can be used to compute the number of moles of MgCl2 that are created.

HCl + 2 Mg + MgCl2 + H2

The amount of moles of MgCl2 that are created when 2.55 mol of Mg react can be estimated as follows: 2.55 mol Mg (1 mol MgCl2/1 mol Mg) = 2.55 mol MgCl2.

Now, we need to multiply the number of moles by the molar mass of MgCl2, which is 95.21 g/mol, in order to convert moles of MgCl2 to grams.

242.89 g MgCl2 from 2.55 mol MgCl2 and 95.21 g/mol

As a result, 2.55 mol of magnesium will result in 242.89 g of MgCl2.

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Hard water is water that contains calcium ions or magnesium ions.

The term hard water is water that contains calcium ions or magnesium ions.  These ions are able to interact with soap and prevent the formation of lather thereby making it difficult for this water to be used in washing.

However, hard water is good for building strong bones as well as for building the calcareous shell of organisms.

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The superscript preceding each hydrogen atomic symbol (h) represents the mass number.

The mass number is the total number of protons and neutrons in the nucleus of an atom. It is represented by the superscript preceding the atomic symbol of an element. In the case of hydrogen (H), hydrogen atoms can have different mass numbers due to the presence of different numbers of neutrons.

For example, the most common isotope of hydrogen, known as protium, has a mass number of 1. It is denoted as ¹H. Deuterium, another isotope of hydrogen with one neutron in addition to one proton, has a mass number of 2 and is represented as ²H. Tritium, which contains two neutrons and one proton, has a mass number of 3 and is denoted as ³H.

The superscript preceding the atomic symbol provides information about the specific isotope of the element and allows distinguishing between isotopes with different numbers of neutrons.

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Irony: a situation in which there is a contrast between expectation and reality.Irony can take many different forms.

The verbal irony, dramatic irony, and situational irony are the three types .Irony occurs in literature AND in life whenever a person says something or does something that departs from what they (or we) expect them to say or do.

Irony in the story 'Dusk':

Ironically, the main character, who thinks he is a good character judge, is duped by the young man who sat next to him on the park seat.

According to Gortsby, darkness is a time when dejected and shady people emerge.

The term irony has its roots in the Greek comic character Eiron, a clever underdog who by his wit repeatedly triumphs over the boastful character Alazon. The Socratic irony of the Platonic dialogues derives from this comic origin.

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pH = 4.3. The hydrogen ion shown above H⁺ is equivalent to the hydronium ion shown.

This material is an ion because it has a charged and is made up of a hydrogen atom with a charge (H+) added. Its formula is H3O+, and it is referred to as the hydronium ion. Whenever an acid comes into contact with water, the hydronium ions are always created. generating H3O+, the acid's H+, by continuously reacting with the adjacent water molecule.

In all alkaline aqueous solutions, the hydroxide ion ion (H3O+), also referred to as nucleophile water, is present. Brnsted acids release one or more of their electrons as h+ ions, which combine with water molecules.

HOCL ⇆ H⁺ + 0CL⁻

Kₐ =H⁺ * 0CL⁻/HOCL

Ka of HOCl = 2.9×10⁻⁸

Kₐ = x²/C

2.9×10⁻⁸ = x²/ 0.100M

x = H⁺= 5.4 * 10⁻⁵

pH = -log H⁺ = 4.3

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