melting point determination can be used for several purposes. what are those purposes?

The standard enthalpy change for reaction (3) is 117.1 kJ.

The standard enthalpy change for reaction (3) can be calculated by using the enthalpy changes of reactions (1) and (2) and applying Hess's Law.

To do this, we need to manipulate the given equations so that the desired reaction (3) can be obtained.

First, we reverse reaction (1) to get the formation of C2H4(g) from C2H6(g):

C2H4(g)C2H6(g) ΔH° = -52.3 kJ

Next, we multiply reaction (2) by 2 and reverse it to obtain 2 moles of C2H6(g) reacting to form 3 moles of H2(g):

2C2H6(g)2C(s) + 3H2(g) ΔH° = 169.4 kJ

Now, we add the two modified equations together:

C2H4(g)C2H6(g) ΔH° = -52.3 kJ
2C2H6(g)2C(s) + 3H2(g) ΔH° = 169.4 kJ

When adding these equations, the C2H6(g) on the left side cancels out with the C2H6(g) on the right side, leaving us with the desired reaction (3):

C2H4(g) + H2(g)C2H6(g) ΔH° = -52.3 kJ + 169.4 kJ = 117.1 kJ

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a. The scientist in the above story is James Cook, the famous British explorer.

b. The "experiment" that James Cook conducted was putting his crew on a strict diet plan that included sauerkraut.

c. The "chemical" used in his experiment was vitamin C, although it was not known at the time.

d. James Cook used his knowledge and observations to serve others by implementing a diet plan that helped prevent scurvy among his sailors.

e. This story highlights that scientific discoveries can be made even without a complete understanding of the underlying chemistry.

a. The scientist in the above story is James Cook, the famous British explorer.

b. The "experiment" that James Cook conducted was putting his crew on a strict diet plan that included sauerkraut.

c. The "chemical" used in his experiment was vitamin C, although it was not known at the time.

d. James Cook used his knowledge and observations to serve others by implementing a diet plan that helped prevent scurvy among his sailors. By requiring his crew to eat sauerkraut, which happened to contain vitamin C, he unknowingly provided them with the necessary nutrient to stay healthy and avoid the illness.

e. This story highlights that scientific discoveries can be made even without a complete understanding of the underlying chemistry. James Cook's use of sauerkraut as a preventive measure against scurvy demonstrates that valuable knowledge and effective solutions can come from observation, experimentation, and practical applications. It also emphasizes that anyone can contribute to scientific advancements, as Cook, an explorer rather than a trained scientist, made a significant impact on the health of his crew through his innovative approach. This story shows that chemicals, in this case, vitamin C, can be found in natural sources, and scientific discoveries can be made by individuals from various backgrounds and professions.

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H2O⋅⋅⋅⋅⋅⋅H−CH3 shows intermolecular attraction between water molecules and methane molecules, but not a hydrogen bond specifically.

A hydrogen bond is a type of intermolecular attraction that occurs when a hydrogen atom is bonded to an electronegative atom such as nitrogen, oxygen, or fluorine, and it is attracted to another electronegative atom in a nearby molecule. This attraction is represented by a dotted line.

Looking at the choices provided, the only option that shows a hydrogen bond is H3N⋅⋅⋅⋅⋅⋅H−O−H. In this molecule, the hydrogen atom in the H−O−H group is bonded to the highly electronegative oxygen atom, and it forms a hydrogen bond with the lone pair of electrons on the nitrogen atom in the H3N group.

The dotted line between the H and N represents the hydrogen bond.

In contrast, the other options do not show a hydrogen bond. H−H represents a simple covalent bond between two hydrogen atoms, while H4C⋅⋅⋅⋅⋅⋅H−F represents a covalent bond between a carbon atom and a fluorine atom, with no electronegative atoms capable of forming a hydrogen bond. H2O⋅⋅⋅⋅⋅⋅H−CH3 shows intermolecular attraction between water molecules and methane molecules, but not a hydrogen bond specifically.

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A mixture of cis- and trans-3-methyl-2-hexene is hydroxylated, as shown in the diagram below. The most common definition of hydroxylation in chemistry is a chemical process.

A hydroxyl group is added to an organic molecule as a result (OH).The degree of hydroxylation refers to how many OH groups are present in a given molecule (ii). the process of hydroxylation. A hydrocarbon utilised in organic chemistry is hexene, which has the chemical formula C6H12. A chemical with two carbon atoms joined by a double bond is known as an alkene, and the prefix "-ene" denotes its presence. The word "hex" comes from the fact that the molecule has six carbon atoms in it.

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Answer:

A. Circulatory System

Answer:

Detail is given below.

Explanation:

Atomic radii along period.

As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required.

Atomic radii trend along group:

As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.

As the size of atom increases the ionization energy from top to bottom also  decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.

When the suspension is let to stand, the dispersed nano-particles come apart from the dispersing phase. A suspension is a uniform mixture of a single material's particles dispersed across a second stage.

A suspension is a homogenous mixture made up of two or more components. Most of the nanoparticles are evenly distributed throughout the liquid and thus are plain to see with the na-ked eye. Instead of dissolving in the solution, the solute's particles remain suspended there.

How a suspension works is based on the idea of force dispersion, which includes converting force into heat or eradicating the effects that force would have had. Struts, dam-pers, & springs are employed to accomplish this.

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The effects of long-term exposure to mustard gas causes mortality and chronic respiratory disease.

Exposure to mustard gas in the long term can result in mortality from influenza, pneumonia as well as chronic breathing disease. Exposure for long term leads to respiratory complications and septic shock. Extensive breathing in the environment of mustard gas can cause chronic respiratory disease, respiratory infections or death.

Extensive eye exposure to this gas can cause permanent blindness. Exposure to mustard gas may also increase the chances of lung and respiratory cancer so we can conclude that mustard gas is lethal and can cause a number of diseases in a person who is exposed to it.

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Answer:

262.8577 g/mol

Explanation:

The molar mass and molecular weight of Mg3O8P2 is 262.858.

Answer:

The molar mass and molecular weight of Mg3O8P2 is 262.858.

Explanation:

Answer:

the equation could have mulitplication and square roots which may change the function of the line

The sample of oxygen will occupy approximately 18.5 mL at -70 °C and the same pressure.

The force exerted by a gas on specific area is known as gas pressure..

As we know, (P₁ V₁) /(T₁) = (P₂V₂) /(T₂)

Given, P₁ is the initial pressure (452 torr); V₁ is initial volume (32.2 mL)

T₁ is initial temperature in Kelvin (30 °C + 273.15 = 303.15 K)

P₂ is final pressure (452 torr); V₂ is final volume (what we want to find)

T₂ is the final temperature in Kelvin (-70 °C + 273.15 = 203.15 K)

Now, V2 = (P₁ V₁ T₂) / (P2 T₁)

V₂ = (452 torr x 32.2 mL x 203.15 K) / (452 torr x 303.15 K)

V₂ ≈ 18.5 mL

Therefore, the sample of oxygen will occupy approximately 18.5 mL at -70 °C and the same pressure.

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Answer:

nitrogen because it has less number of protons and electrons, thus a samller atomic mass

Explanation:

Explanation:

Water is a polar substance. Polar solvents dissolve polar substances. Now, the bond between carbon and hydrogen is a covalent bond, because the electronegativity difference between these two elements is less than 1.7.

Therefore, the low solubility of hexane is due to the fact that hexane is nonpolar with covalent bonds.

Answer: C) Nonpolar covalent

a) To calculate the molarity of the solution, use the formula: Molarity = moles of solute / volume of solution in liters.

Given 0.175 moles of calcium nitrate and 50.00 mL of solution, first convert the volume to liters: 50.00 mL * (1 L / 1000 mL) = 0.050 L, Now, calculate the molarity: Molarity = 0.175 moles / 0.050 L = 3.50 M. So, the molarity of the solution is 3.50 M.

(b) To find the grams of calcium nitrate dissolved in the solution, first determine the molar mass of calcium nitrate (Ca(NO₃)₂):
Ca = 40.08 g/mol
N = 14.01 g/mol
O = 16.00 g/mol.

Molar mass of Ca(NO₃)₂ = 40.08 + 2(14.01 + 3(16.00)) = 164.10 g/mol
Now, multiply the moles of calcium nitrate by its molar mass: 0.175 moles * 164.10 g/mol = 28.7175 g
Therefore, 28.72 grams of calcium nitrate are dissolved in the solution (rounded to two decimal places).

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Answer: She could have put a steel spoon into the vessel. The correct option is A.

Explanation:

When a candle wax is passed through heat, it is capable of melting within 10- 15 minutes of boiling. Therefore it is not capable of looking the same after 30 mins of heating.

When sugar is put into water it dissolves. When heated it has the ability to crystallize out after water is evaporated but doesn't retain its shape.

A piece of chocolate will melt the instance it comes in contact with any form of heat.

A steel spoon is an alloy metal which is not capable of melting by boiling in water for just 30 minutes. A steel is an alloy of Iron and carbon which melts when superheated at the temperature of 1510 degrees.

The voltage of the given cell is approximately 1.0704 V.

To calculate the voltage of the given cell, we can use the Nernst Equation:

E_cell = E°_cell - (RT/nF) * ln(Q)

Where:

E°_cell = standard cell potential
R = gas constant (8.314 J/mol*K)
T = temperature in Kelvin (usually 298 K)
n = number of moles of electrons transferred (2 for Zn and Cu)
F = Faraday's constant (96485 C/mol)
Q = reaction quotient, [Cu²⁺]/[Zn²⁺]

First, we need to find the E°_cell for the given reaction, which is the difference in standard reduction potentials:

E°_cell = E°_Cu - E°_Zn

The standard reduction potentials for the half-reactions are:

E°_Cu = +0.34 V (for Cu²⁺ + 2e⁻ → Cu)

E°_Zn = -0.76 V (for Zn²⁺ + 2e⁻ → Zn)

Therefore,

E°_cell = (+0.34 V) - (-0.76 V)

           = +1.10 V

Now, we can calculate Q:

Q = [Cu²⁺]/[Zn²⁺]

   = (0.10 M)/(0.20 M)

   = 0.5

Now, plug all the values into the Nernst Equation:

E_cell = 1.10 V - (8.314 J/mol*K * 298 K)/(2 * 96485 C/mol) * ln(0.5)

E_cell ≈ 1.10 V - 0.0296 V

          = 1.0704 V

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To calculate the error in a standard solution of chemistry 14cl, you need to first measure the exact mass of the solution and subtract the amount you initially put in the solution. The result is the error.

For example, if you put 10 g of chemistry 14cl into a solution and measure the exact mass to be 10.4 g, the error would be 0.4 g.

To calculate the error in a standard solution in chemistry, you need to follow these steps:

1. Calculate the amount of substance you should have in your solution. This is typically given in the question, or you can calculate it using the formula n = cV, where n is the amount of substance, c is the concentration, and V is the volume.

2. Calculate the amount of substance you actually have in your solution. This can be done by weighing the solution and using the formula m = nM, where m is the mass, n is the amount of substance, and M is the molar mass.

3. Calculate the difference between the amount of substance you should have and the amount you actually have. This is the error in your solution.

4. Divide the error by the amount of substance you should have to get the percent error. This is typically reported as a percentage.

For example, if you were supposed to have 14cl of a substance in your solution, but you actually have 13.8cl, the error would be 0.2cl. The percent error would be (0.2/14) * 100 = 1.43%.

So, the error in a standard solution in chemistry can be calculated by finding the difference between the amount of substance you should have and the amount you actually have, and then dividing by the amount you should have to get the percent error.

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Answer: np

Explanation:

Correctly matched are :

A landslide is also called a land slip. It refers to several forms of mass wasting and may include a wide range of ground movements. They occur in a variety of environments characterize by gentle and steep slope gradients.

The mudflow is a mixture of rocks and soil along with water. While a creep is a slow downloads movement of rocks and soil.

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The correct list of three methods of heat transfer is conduction, convection, and radiation. The correct option is B.

A phenomenon known as "heat transfer" occurs when heat is transferred between two physical objects. High temperatures always transfer heat to lower temperatures. A hot body always loses heat to a cool body. Conduction, convection, and radiation are the three processes involved in the transport of heat.

Heat is conveyed via conduction when two things are in direct touch with one another. Convection is the process by which heat is moved within the fluid. Without the usage of particles, electromagnetic waves carry heat during radiation. The heat transfer is triggered by the temperature difference.

Thus, the correct option is B. conduction, convection, and radiation.

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The Adol condensation reaction may form a product with a newly created alkene, which can exist as either E or Z isomers, depending on the stereochemistry of the starting materials used in the reaction.

What is the configuration of newly created alkenes in the Adol condensation reaction?

In the Adol condensation reaction, the reactants are an aldehyde or ketone and a carbonyl compound (aldehyde or ketone). The reaction results in the formation of a β-hydroxyketone or aldehyde. The product may contain an alkene depending on the reaction conditions and the reactants used.

If the product contains a newly created alkene, the configuration of the double bond would depend on the stereochemistry of the starting materials. If the carbonyl compounds used in the reaction have different substituents on the carbonyl carbon, the resulting alkene can exist as either E or Z isomers, depending on the relative orientation of the substituents on either side of the double bond.

The stereochemistry of the product can be predicted using Zaitsev's rule, which states that the more substituted alkene is formed as the major product. However, the stereochemistry of the alkene in the product can also be influenced by factors such as steric hindrance and the reaction conditions used.

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The answer should be d) 10, 12, 22

Answer:

See explanation

Explanation:

The formation of isomers is common to octahedral complexes. Isomers are different compounds with the same molecular formula but different structural formulas. Isomers have different atom to atom connections. Werner's complexes can display; polymerization, ionization, linkage, geometric and optical isomerism among others.

Isomers of coordination compounds are not easily recognizable and not easily separable in the laboratory.

The geometric, linkage and ionization isomers of the complex given in the question are shown below.

Answer:

The correct options are;

1. 1,600

2. 100 Watts

A 23-30 watt CFL provides 1,600 lumens and is equivalent to a 100 Watts incandescent bulb

Explanation:

Brightness is measured in lumens and watts measure energy usage therefore with the use of an energy saving light bulb, the same lumination can be obtained at a lower energy usage.

According to a comparison chart for LED Lights vs. Incandescent Light Bulbs vs. Compact Fluorescents (CFLs) from USAI lightening website 23-30 watts CFL has a light output of 1,600 and is therefore produces enough light as a 100 Watts Incandescent Light Bulb

Also according to energy.gov website, CFLs save up to 75% energy such that a 23-30 watt CFL can produce the same illumination as a 100 watt incandescent bulb

Therefore we have, a 23-30 watt CFL provides 1,600 lumens and is equivalent to a 100 Watts incandescent bulb.

Answer:

1600 lumens, 100 watt incandescent

Explanation:

100% on edge (:

The synthesis of 2-propyl-1,3-propanediol using either the malonic ester synthesis or the acetoacetic ester synthesis involves the steps of alkylation, hydrolysis, decarboxylation, and reduction, with the specific reagents depending on the starting material used.

The beginning material for this union isn't given in the inquiry. Accepting the beginning material is ethyl malonic ester, the malonic ester union can be utilized to blend 2-propyl-1,3-propanediol as follows:

Alkylation: Ethyl malonic ester is alkylated with 1-bromopropane within the sight of sodium ethoxide to shape 2-propylmalonic ester (\(EP_{1}\)).

Hydrolysis: 2-Propylmalonic ester is hydrolyzed with fluid sodium hydroxide to frame 2-propylmalonic corrosive (\(EP_{2}\)).

Decarboxylation: 2-Propylmalonic corrosive goes through decarboxylation to frame 2-propylpropanal (\(EP_{3}\)).

Decrease: 2-Propylpropanal is diminished with sodium borohydride to frame 2-propyl-1,3-propanediol (\(EP_{4}\)).

On the other hand, expecting the beginning material is ethyl acetoacetate, the acetoacetic ester combination can be utilized to orchestrate 2-propyl-1,3-propanediol as follows:

Alkylation: Ethyl acetoacetate is alkylated with 1-bromopropane within the sight of sodium ethoxide to shape 2-propylacetoacetate (\(EA_{1}\)).

Hydrolysis: 2-Propylacetoacetate is hydrolyzed with fluid sodium hydroxide to frame 2-propylacetoacetic corrosive (\(EA_{2}\)).

Decarboxylation: 2-Propylacetoacetic corrosive goes through decarboxylation to frame 2-propylpropanal (\(EA_{3}\)).

Decrease: 2-Propylpropanal is diminished with sodium borohydride to frame 2-propyl-1,3-propanediol (\(EA_{4}\)). The particular reagents expected for each step of the blend would rely upon the circumstances and the beginning material utilized. Notwithstanding, in light of the gave table, a few potential reagents that could be utilized are sodium ethoxide (EtONa), fluid sodium hydroxide (NaOH), and sodium borohydride (\(NaBH_{4}\)).

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The complete question is:

Show how to synthesize 2-propyl-1,3-propanediol using either the malonic ester synthesis or the acetoacetic ester synthesis and reagent(s) from the table provided below.

Indicate which synthesis is used by choosing between Malonic Ester or Acetoacetic Ester as the starting material.The starting material for this synthesis is: From the choices provided, list the reagent(s) in order that will accomplish this transformation. No more than 6 steps are required.List your answer as a single letter (single-step transformation) or a series of letters (multi-step transformation) with no commas separating them.

For example, "ai" corresponds to:

1. \(EtO^{-} Na^{+}\)

2. \(CH_{3} CH_{2} Br\)

The conclusion is that chloride does not emit light in visible range.

As per the image, we can see the differentiating factors are the metal ions. With different metals, the chloride salt gives different flame colour.

As we know, all the electrons absorb energy and emit it while returning from excited state to ground state. The wavelength of this emitted energy is perceived by us as colours.We can state that these colours are of metals and chloride ions themself do not emit colour in visible range.

Also, metal salts of chlorine are volatile. The metal chloride vapourises quickly and hence is suitable for the detection of metal ions.

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The image is attached in the diagram..

1 mol of Li₂CO₃ (aq) will dissociate into two Li⁺ ions and one CO₃²⁻ ion. When Li₂CO₃ dissolves in water, the molecules of the salt separate and the Li⁺ and CO₃²⁻ ions are formed.

The two Li⁺ ions become surrounded by water molecules, forming hydrated ions. The CO₃²⁻ ions are not hydrated, so they remain as free ions in solution. The ionic bonding between the Li⁺ and CO₃²⁻ ions is broken due to the strong polarizing power of the water molecules.

The Li⁺ and CO₃²⁻ ions then move freely in the solution due to the electrostatic repulsive forces between them. These ions also interact with the water molecules and the other ions present in the solution.

The Li⁺ and CO₃²⁻ ions are then further dispersed throughout the solution, forming a homogeneous solution of the salt.

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Boiling points,conductivity and colours contain only physical properties