Find the specific heat of an unknown material with an initial temperature of 20°C, when 5000 Joules are applied to a 50 gram sample and the final temperature is 70°C

The rate constant at 18°C is approximately 4.36×10^-5 s^-1. The activation energy determines the rate of a reaction, as reactions with higher activation energies require more energy and therefore occur more slowly than reactions with lower activation energies.

What is Activation Energy?

It is the energy required for reactant molecules to collide with enough force to overcome the energy barrier and form products.

To determine the activation energy of the reaction, we can use the Arrhenius equation:

k = A e^(-Ea/RT)

where k is the rate constant, A is the pre-exponential factor, Ea is the activation energy, R is the gas constant (8.314 J/mol·K), and T is the temperature in Kelvin.

We can use the given rate constants and temperatures to set up two equations and solve for the activation energy:

k1 = A e^(-Ea/RT1)

k2 = A e^(-Ea/RT2)

Taking the ratio of the two equations eliminates the pre-exponential factor:

k2/k1 = e^(Ea/R (1/T1 - 1/T2))

Substituting in the given values:

k2/k1 = 0.232 s^-1 / 1.23×10^-4 s^-1 = 1886.2

T1 = 26 + 273.15 = 299.15 K

T2 = 79 + 273.15 = 352.15 K

Solving for Ea:

ln(k2/k1) = (-Ea/R) (1/T1 - 1/T2)

Ea = -R ln(k2/k1) / (1/T1 - 1/T2)

Ea = -8.314 J/mol·K * ln(1886.2) / (1/299.15 K - 1/352.15 K)

Ea ≈ 90.7 kJ/mol

Therefore, the activation energy of the reaction is approximately 90.7 kJ/mol.

To find the rate constant at 18°C, we can use the same Arrhenius equation:

k = A e^(-Ea/RT)

Rearranging the equation and solving for k:

k = A e^(-Ea/RT) = k1 e^(Ea/R (1/T1 - 1/T))

Substituting in the given values:

k1 = 1.23×10^-4 s^-1

R = 8.314 J/mol·K

T1 = 26 + 273.15 = 299.15 K

T = 18 + 273.15 = 291.15 K

k = 1.23×10^-4 s^-1 * e^(90.7 kJ/mol / (8.314 J/mol·K * (1/299.15 K - 1/291.15 K)))

k ≈ 4.36×10^-5 s^-1

Therefore, the rate constant at 18°C is approximately 4.36×10^-5 s^-1.

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Yes, all the liquid will evaporates,

given that :

vapor pressure of liquid carbon disulfide = 100mmHg = 0.1315 kpa

temperature = 268 K

volume of the container = 370 mL = 0.370 L

using ideal gas equation we get :

PV = n R T

n = P V / R T

n = ( 0.315 × 0.370 ) / ( 0.0823 × 278)

n = 0.0050 mol = 5.0 × 10⁻³ mol

number of moles of CS₂ = mass / molar mass

                                        = 0.0979 / 76.139

                                        = 0.00128 mol

                                        = 1.2 × 10⁻³ mol

it is clear that , the vapor pressure of liquid carbon disulfide, , is 100. mm hg at 268 k. a 0.0979 g sample of liquid is placed in a closed, evacuated 370. ml container at a temperature of 268 k. yes the temperature remains constant, all of the liquid evaporate.

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Ionization energy increases as we move across the period from left to right.

order of ionization energy across period 2

Li < B < Be < C < O < N < F < Ne

What is Ionization energy?

Trends for Ionization energy

order of ionization energy across period 2

Li < B < Be < C < O < N < F < Ne

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Answer:

? the question isn't clear

Explanation:

Answer:

yes

Explanation:

Answer:

It would be very unlikely that a volcanic eruption will occur in the mainland (Midwest or surrounding) to occur.

Explanation:

The nearest platonic plates are in California in the triangle with Japan and China, the chances of earthquakes are also low in this area due to the fact that no plates could collide to produce an earthquake, or form a volcano.

Answer:

2. 232 & 86

Explanation:

A major product of the acid-catalyzed hydration of an alkene is CH3-CH2-CH2-OH,(CH3)2-OH-C-CH2-CH3.

Unsaturated compounds with at least one double bond between carbon atoms make up the class of hydrocarbons known as alkenes, which only include carbon and hydrogen. Olefins is yet another word for alkenes. Because they include a double bond, alkenes are more reactive than alkanes. Any hydrocarbon with one or more double bonds is referred to as a "olefin" and is frequently referred to as a "lkene." One can distinguish between internal and terminal monoalkenes. Terminal alkenes, also referred to as -olefins, are more advantageous.

However, the International Union of Pure and Applied Chemistry (IUPAC) suggests using the name "alkene" only for acyclic hydrocarbons with a single double bond, alkadienyl, alkatriene, etc., or polyene for acyclic hydrocarbons with two or more double bonds, and cycloalkene, cycloalkadiene, etc.

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By dividing water, the electron that was lost from the chlorophyll special pair is replaced. Protons are pumped from the stroma to the thylakoid lumen as a result of the electron passing through the first link in the electron transport chain.

The electrons from photosystem II that have traveled via the electron transport chain replace the electrons lost by these chlorophyll molecules. The two chlorophyll "a" molecules of photosystem II are compelled by light energy to go up an energy level.

The energy storage molecule ATP and the reduced electron carrier NADPH are produced by the light-dependent processes using light energy, which is required for the subsequent stage of photosynthesis. Light reactions in plants occur in the thylakoid membranes of organelles referred to as chloroplasts in chlorophyll.

The light reactions are largely controlled by photosystems, sizable complexes of proteins, and pigments (light-absorbing molecules) that are designed to capture light. Photosystem I (PSI) and Photosystem II are the two different types of photosystems (PSII). Via a process known as photolysis, the chlorophyll molecule regains the lost electron from a water molecule, releasing dioxygen (O2) in the process.

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Answer:

some of the salt molecules are dissociated into ions, which allows the ions to conduct electricity.

Explanation:

hope it helps

Assuming the surface on which the box moves is frictionless, the rate at which the box accelerate is equal to 0.5 \(m/s^2\).

Given the following data:

To determine the rate at which the box accelerate, assuming the surface on which the box moves is frictionless:

Mathematically, Newton's Second Law of Motion is given by the formula;

\(Force = mass \times acceleration\)

Making acceleration the subject of formula, we have:

\(Acceleration =\frac{Force}{mass}\)

Substituting the given parameters into the formula, we have;

\(Acceleration = \frac{25}{50}\)

Acceleration = 0.5 \(m/s^2\)

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The moles of solute needed to prepare each of the following:

a) 3 moles

b) 0.4 moles

c) 0.25 moles

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The M904 and M905 delay elements are part of the guidance system used for the Standard Missile 3 (SM-3) interceptor missile. The M904 delay element is placed between the missile's boost motor and the separating stage, while the M905 delay element is placed between the missile's separating stage and the guided missile's rocket motor.

These delay elements are inserted into the missile's payload at specific times and for specific reasons:

Answer:

fusion reaction

The simple answer is that the sun, like all stars, is able to create energy because it is essentially a massive fusion reaction. Scientists believe that this began when a huge cloud of gas and particles (i.e. a nebula) collapsed under the force of its own gravity – which is known as Nebula Theory.

Explanation:

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Answer:

Carbon flows between the atmosphere, land, and ocean in a cycle that ... Coal and other fossil fuels are a convenient source of energy, but when ... If carbon dioxide rises in the atmosphere because of an increase in ... However, the slow carbon cycle also contains a slightly faster component: the ocean.

Explanation:

I got you fam

The molecular weight of gas X would be 23.36 g/mol.

According to Graham, the rate of effusion of gases is inversely proportional to the square root of their molecular weights.

Graham's law can be mathematically expressed as:

\(r_1/r_2\) = \(\sqrt{\frac{m_2}{m_1} }\)

Where \(r_1\) and \(r_2\) are rates of diffusion or effusion of gases 1 and 2, and \(m_1\) and \(m_2\) are their molecular weights respectively.

In this case, \(r_x\) = \(2.5r_{SF6}\) and the molecular weight of Sf6 is given as 146 g/mol. Thus:

2.5 = \(\sqrt{\frac{146}{m_x} }\)

6.25 = 146/\(m_x\)

\(m_x\) = 146/6.25

      = 23.36 g/mol

In other words, the molecular weight of gas X would be 23.36 g/mol.

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Answer:

Caustic soda

Explanation:

The fractional distillation of air is carried out on liquid air. Before air is liquified, the carbon dioxide content of air is removed using caustic soda. The air is then compressed to a pressure of about 200 atm, sudden expansion of the gas leads to cooling. The process continues until air becomes liquid at  -200°C.

Fractional distillation of liquid air usually produces nitrogen and oxygen as major products. nitrogen in obtained first since it has a lower boiling point than oxygen. The gases are then dried, compressed and stored in cylinders.

Answer: 2nd one

Explanation:

PLATO

Answer:

See Below

Explanation:

'an aerobic ' means it does not use oxygen

Answer:

anaerobic

Explanation:

To determine the pH of a solution with a given hydroxide ion concentration, we need to use the equation for the ion product constant of water (Kw) which is equal to 1 x 10^-14 at 25°C.

Kw = [H+][OH-]

Rearranging the equation, we can solve for the pH:

pH = -log[H+]

[H+] = Kw / [OH-] = (1 x 10^-14) / (2.5 x 10^-2) = 4 x 10^-13

pH = -log(4 x 10^-13) = 12.40

Therefore, the pH of the solution is e. 12.40.

This means that the solution is basic since the pH is greater than 7. A pH of 12.40 indicates that the solution is highly basic or alkaline, which means that it has a high concentration of hydroxide ions (OH-).

A higher concentration of hydroxide ions means that the solution is more likely to accept protons (H+) and can therefore neutralize acids. It is important to note that maintaining the proper pH balance is important for many chemical reactions and biological processes in the body.

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The second most abundant element in the solar system is helium (He).

Helium is an inert gas and is the second lightest element in the periodic table, after hydrogen (H). It is formed primarily through nuclear fusion processes in stars, such as the Sun. In the core of stars, hydrogen nuclei combine to form helium through the process of nuclear fusion, releasing a tremendous amount of energy in the process.

In the solar system, helium is abundant due to the vast number of stars, including the Sun, which produce and release helium into space through stellar processes like stellar winds and supernova explosions. Helium is also present in smaller amounts in gas giants like Jupiter and Saturn.

The abundance of helium in the solar system can be attributed to its formation during stellar nucleosynthesis and its resistance to chemical reactions, allowing it to accumulate and persist over billions of years. As a result, helium ranks as the second most abundant element in the solar system, following hydrogen.

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Answer:

Light as a wave: Light can be described (modeled) as an electromagnetic wave. In this model, a changing electric field creates a changing magnetic field. This changing magnetic field then creates a changing electric field and BOOM - you have light. ... So, Maxwell's equations do say that light is a wave.

Explanation:

Hope this helps

Answer:

Light as a wave: Light can be described (modeled) as an electromagnetic wave. In this model, a changing electric field creates a changing magnetic field. This changing magnetic field then creates a changing electric field and BOOM - you have light. ... So, Maxwell's equations do say that light is a wave.

Explanation:

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Answer:

Question 8, I think is C describe CR. Question 7 is Chemical reactions produce new substances

Explanation:

Cleaning supplies should be stored away from food for several important reasons:

1. Contamination: Cleaning supplies often contain chemicals that can be harmful if ingested. If they come into contact with food, they can contaminate it and pose a risk to human health. Some common cleaning agents, such as bleach, ammonia, and disinfectants, can cause nausea, vomiting, diarrhea, or more serious health issues if consumed.

2. Chemical reactions: Certain cleaning products can undergo chemical reactions when they come into contact with certain food items. For example, mixing bleach and acidic foods or liquids (such as vinegar, citrus fruits, or juices) can create toxic chlorine gas. Storing cleaning supplies near food increases the risk of accidental mixing or spillage, leading to dangerous chemical reactions.

3. Packaging mix-ups: Cleaning supplies and food items often come in similar packaging, such as spray bottles or containers. Placing them in close proximity increases the chances of mistakenly using the wrong product. Consuming cleaning products can be extremely hazardous and cause severe harm or even death.

4. Cross-contamination: Even if the cleaning supplies don't directly contact the food, there is still a risk of cross-contamination. Residual chemicals or fumes from the cleaning supplies can migrate to nearby food items, compromising their safety and quality.

To ensure food safety, it is crucial to store cleaning supplies in a separate, designated area away from food storage areas, preferably in a locked cabinet or a well-ventilated storage space. It's important to read and follow the instructions on cleaning product labels, use them as intended, and keep them out of reach of children and pets.

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In the presence of extra Mg3N2, a reaction involving 7 moles of Mg(OH)2 requires 14 moles of water.

A mole is the volume of a substance that contains 6.022 X 1023 of the substance's particles, atoms, ions, molecules, etc. A mole is a unit for counting molecules, ions, or atoms.

The reaction between Mg(OH)2 and H2O has the following balanced chemical equation:

Mg(OH)2 + 2H2O → Mg(OH)2·2H2O

This indicates that 2 moles of water react with 1 mole of Mg(OH)2.

We may determine how many moles of water are required by using the following formula since we have 7 moles of Mg(OH)2.

7 moles Mg(OH)2 × (2 moles H2O / 1 mole Mg(OH)2) = 14 moles H2O.

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Answer:

5 atoms are in each molecule of calcium carbonate

The chemical breakdown of hydrogen-containing compounds requires an input of energy in the form of heat or light. This energy is required to break the bonds between the atoms in the compound, allowing them to react with other compounds or elements.

Hydrogen-containing compounds, such as hydrocarbons and carbohydrates, are typically composed of carbon and hydrogen atoms bonded together in covalent bonds. These bonds are strong and require energy to break apart. When energy is added to the system, it can be absorbed by the electrons in the bonds, which become excited and move to higher energy levels. This increased energy makes the bonds more unstable, allowing them to break apart more easily and react with other compounds.

The input of energy required for the chemical breakdown of hydrogen-containing compounds is known as the activation energy. This energy is needed to overcome the energy barrier that exists between the reactants and products in a chemical reaction. Once this energy barrier is overcome, the reaction can proceed spontaneously, releasing energy in the form of heat or light. The amount of energy required for a given reaction depends on the specific compounds involved and the conditions under which the reaction occurs.

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A pyrophoric substance is a material that ignites spontaneously in the presence of air or oxygen at or below room temperature.

The exact temperature required for a pyrophoric substance to ignite spontaneously depends on the specific material and the conditions under which it is being used.

In general, pyrophoric substances have a low ignition temperature, typically between 200-400°C (392-752°F). However, some pyrophoric materials can ignite at much lower temperatures, such as iron powder, which can ignite spontaneously at temperatures as low as 80°C (176°F).

The ignition temperature of a pyrophoric material can also depend on the specific conditions under which it is being handled. For example, a pyrophoric substance may ignite more easily if it is finely divided or if it is exposed to moisture or other reactive substances.

It is important to handle pyrophoric substances with care and to follow appropriate safety protocols to minimize the risk of ignition and fire. This may include storing pyrophoric materials in a dry, inert atmosphere and using appropriate personal protective equipment when handling them.

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