explain what is meant by an exothermic reaction and write balanced equation for any two exothermic changes

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Answer: butter melts

Explanation:

Answer:

Explanation:

To determine the freezing temperature of a solvent and solute mixture, you will need to use the freezing point depression equation. This equation allows you to calculate the change in freezing point of a solvent caused by the addition of a solute.

The freezing point depression equation is:

ΔTf = Kf x molality

where:

ΔTf is the change in freezing point of the solvent in degrees Celsius

Kf is the freezing point depression constant for the solvent, which is a specific value for each solvent and is usually provided in a table or chart

molality is the concentration of the solute in the solvent, expressed in mol/kg

To use this equation, you will need to know the volume and density of the solvent and solute, as well as the molecular weight of the solute. You can then use these values to calculate the molality of the solute in the solvent.

For example, let's say you have a mixture of 100 mL of water (solvent) and 10 g of salt (solute). The density of water is 1 g/mL and the molecular weight of salt is 58.44 g/mol.

To calculate the molality of the salt in the water, you can use the following steps:

Calculate the mass of the solvent: 100 mL x 1 g/mL = 100 g

Calculate the molality of the solute: 10 g / 58.44 g/mol = 0.171 mol

Calculate the molality of the solvent: 0.171 mol / 100 g = 0.00171 mol/g

Once you have calculated the molality of the solute in the solvent, you can use the freezing point depression equation to calculate the change in freezing point of the solvent caused by the addition of the solute.

For water, the freezing point depression constant (Kf) is 1.86 °C/m. Therefore, the change in freezing point caused by the addition of the salt to the water would be:

ΔTf = 1.86 °C/m x 0.00171 m = 0.00316 °C

This means that the freezing temperature of the solvent and solute mixture would be 0.00316 °C lower than the freezing temperature of pure water, which is 0 °C. Therefore, the freezing temperature of the mixture would be -0.00316 °C.

I hope this helps! Let me know if you have any questions or need further clarification.

After the substrate binds to the active site of the enzyme, the enzyme-substrate complex may undergo a conformational change, which brings the substrate closer to the catalytic site of the enzyme.

This conformational change is often necessary for the chemical reaction to occur, as it positions the substrate in the proper orientation for the reaction to take place. The conformational change may be induced by the binding of the substrate to the active site, or it may be a result of the substrate interacting with specific amino acid residues within the active site. The conformational change of the enzyme can also help to stabilize the intermediate species formed during the reaction, which helps to increase the rate of the reaction.

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The Answer is Lead tetrachloride, PbCl4 is the molecular formula for lead tetrachloride, also known as lead(IV) chloride. It is a yellow, oily liquid that is stable below 0 degrees Celsius and decomposes at 50 degrees Celsius.  

It is tetrahedral in structure, with lead as the central atom. The covalent bond length of Pb-Cl is 247 pm, and the bond energy is 243 kJmol. Lead tetrachloride can be synthesised by reacting lead(II) chloride PbCl2 with hydrochloric acid HCl in the presence of chlorine gas (Cl2), yielding chloroplumbic acid H2PbCl6. By adding ammonium chloride, it is converted to the ammonium salt (NH4)2PbCl6 (NH4Cl). Finally, concentrated sulfuric acid H2SO4 is added to the solution to separate out the lead tetrachloride.

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The reaction that describe an acid an acid- base neutralization reaction is

[tex]Be(OH)2 + H2SO4 = BeSO4 +2 H2O[/tex]

Neutralization reaction involve an acid  and a base reaction whereby the acid  neutralization the base for the reaction above Be(OH)2 is  the base while it is the acid  thus [tex]H2SO4[/tex] neutralizes  Be(OH)2 to form BeSO4 and [tex]H2O.[/tex]

Reactants: Na = 2, O = 2, H = 2, Cu = 1, Cl = 2;

Products: Na = 2, Cl = 2, Cu = 1, O = 2, H = 2

[tex]NaOH + CuCL2 — > NaCl + Cu(OH)2[/tex]

The balanced equation can be achieved by doing the following:

There are 2 oxygen and 2 hydrogen atom on the right side. This is balanced by putting 2 in front of NaOH as shown below:

[tex]2NaOH + CuCL2 — > NaCl + Cu(OH)2[/tex]

Therefore, The reaction that describe an acid an acid- base neutralization reaction is

[tex]Be(OH)2 + H2SO4 = BeSO4 +2 H2O[/tex]

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Answer: [tex]C_2H_5[/tex]

The amount, in grams, of magnesium that must react with phosphoric acid to produce 100 L of hydrogen gas would be 108.38 grams.

Magnesium reacts with phosphoric acid to produce hydrogen gas and magnesium phosphate according to the following balanced equation:

[tex]3Mg + 2H_3PO_4 -- > Mg_3(PO_4)_2 + 3H_2[/tex]

The mole ratio of the magnesium that reacts to the hydrogen gas that is produced is 1:1.

If, 1 mole of a gas = 22.4 L, then 100 L of hydrogen gas would be equivalent to:

100/22.4 = 4.46 mols

Since the mole ratio is 1:1, the mole of magnesium that will produce 100 L of hydrogen gas will also be 4.46 moles.

Mass of 4.46 moles magneisum = 4.46 x 24.3

                                                       = 108.38 grams

In other words, the amount of magnesium that must react with phosphoric acid in order to produce 100 L of hydrogen gas would be 108.38 grams.

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The density of ammonia gas in a 4.32 l container at 837 torr and 45.0 °c is 0.717 g/L.

Ammonia is a colorless gas that has a strong suffocating odour. It easily dissolves in water, forming an ammonium hydroxide solution that can cause irritation and burns. Approximately 80% of the ammonia produced by industry is used as fertiliser in agriculture. Ammonia is also used as a refrigerant gas, to purify water, and to make plastics, explosives, textiles, pesticides, dyes, and other chemicals.

Molar mass: 17.031 g/mol

The boiling point is -33.34 °C.

The density is 0.73 kg/m3.

Given,

V = 4.32 L

P = 837 torr = 1.101 atm

R = 0.082 atm.L / mol.K

T = 45 + 273.15 = 318.15 K

Formula:

PV = nRT

Moles of NH3 = n = PV/RT

⇒                      = 1.101 x 4.32 / (0.082 x 318.15)

⇒                          = 0.182 mol

Molar mass of NH3 = 17 g/mol

Mass = molar mass x moles

⇒                   = 17 x 0.182

   ⇒                    = 3.10 g

Density = mass / volume

⇒              = 3.10 / 4.32

⇒                  = 0.717 g/L

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The rank solutions from smallest basicity to greatest is

[tex]C_{5}H_{5}NHNO_{2}[/tex] - [tex]NaCHO_{2}[/tex] - [tex]C_{2}H_{5} NH_{3}I[/tex] - NaI - NaOH

Sаlt cаn be аcidic, bаsic аs well аs neutrаl. NаOH hаs the leаst аcidity becаuse it is bаse аnd it gives hydroxyl ions in wаter. Higher is the pH of аny substаnce, lesser will be its аcidity. Lower pH vаlue indicаtes thаt the given substаnce is аcidic.

[tex]NaCHO_{2}[/tex] - It is a basic salt of a weak acid (HCOOH) + strong base (NaOH)

[tex]C_{2}H_{5} NH_{3}I[/tex] - It is an acidic salt of a weak base (Ethyl Amine) + strong acid (NaOH)

NaOH - It is a strong base itself

[tex]C_{5}H_{5}NHNO_{2}[/tex] - It is a weakly acidic salt of  very weak bases (pyridine) + moderately

NaI - It is a neutral sort of strong as HI.

Your question is incomplete, but most probably your full question can see in the Attachment.

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A potassium atom's ground state electron configuration is 1s2, 2s2, 2p6, 3s2, 3p6, 4s1.

An atom's electron configuration is a picture of how electrons are arranged in relation to orbital shells and subshells. Consequently, this is potassium's electron configuration.

Making Electron Configurations in Writing. Write the energy level (the period) first, then the subshell that needs to be filled, and finally the superscript, which indicates how many electrons are in that subshell. The atomic number, Z, is the sum of all the electrons.

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Casting pewter involves tremendous temperatures, which makes it potentially highly dangerous.  Wearing safety gear like the kind pictured below is required, and taking all reasonable safety precautions is crucial.

Gases or scents that are toxic or offensive may be released during burning or thermal breakdown. Unusual Explosion and Fire Risks: When molten, water reacts violently with it.

Despite significant variations, 96% tin and 4% copper make up the majority of modern pewter. It is a soft metal, allowing for simple shaping with both hand and machine tools. A low melting point makes it suitable for casting (230 degrees, roughly).

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Reduction of pyruvate through a reduction reaction results in the formation of lactate.

When sufficient quantity of oxygen is not available for the cell, then pyruvate undergoes a reduction reaction that results in the production of Lactate. This process is called as anaerobic metabolism.

Conversion of pyruvate into lactate during the process of redox reaction oxidizes NADH to NAD+ . This happens because every glucose molecule that will be converted into pyruvate, two NADH molecules are produced and there is need for the NADH molecules to be oxidized back to NAD+ so that to ensure the continuity and maintenance of the glycolysis.

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The direct capture of a free electron by a neutral atom is the easiest technique to create negative ions.

How is an ion made to be negatively charged?

Positive ions made by a positive ion source can be double-charged-exchanged to create negative ions,

or negative ions can be directly extracted from a negative ion source.

creation of negative ions.

Negative ions and other energy levels below the vacuum level can be inhabited by adding an electron to an atom or molecule.

The atom has a net negative charge of e despite not being stable.

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Ionic compounds are defined as the compounds that are made up of ions that form charged particles when an atom (or group of atoms) gains or loses electrons. Some important properties of ionic compounds are discussed below.

Ionic compounds are basically formed between elements that are metals and elements that are nonmetals. For example, let's take the metal calcium (Ca) and the nonmetal chlorine (Cl) form the ionic compound calcium chloride (CaCl₂). In this ionic compound, two negative chloride ions (anions) are present for each positive calcium ion (cations).

Properties of ionic compounds are given as:

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A hybridization to each interior atom in cytosine is as follows Carbon (C): sp3, Nitrogen (N): sp3, Oxygen (O): sp2, Hydrogen (H): s-character.

In the molecule cytosine, the central carbon atom (C) is bonded to three atoms (H, N, and C) and has one lone pair of electrons, resulting in a trigonal pyramidal geometry and sp3 hybridization. The nitrogen atom (N) is bonded to three atoms (C, H, and C) and has one lone pair of electrons, resulting in a trigonal pyramidal geometry and sp3 hybridization. The oxygen atom (O) is bonded to two atoms (C and H) and has two lone pairs of electrons, resulting in a bent geometry and sp2 hybridization. The hydrogen atoms (H) are bonded to one atom (C or N) and have no lone pairs of electrons, resulting in a linear geometry and s-character hybridization.

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The molar enthalpy of vaporization is 374.9 J/mol.

We know that at the boiling point of a substances, the vapor pressure of the substance would become equal to the atmospheric pressure of the substance.

We know that;

ln(P2/P1) = -ΔHvap/R(1/T2 - 1/T1)

P2 = final pressure

P1 = initial pressure

ΔHvap = molar enthalpy of vaporization

T2 = Final temperature

T1 = initial temperature

ln(75/760) = -ΔHvap/8.314(1/15.2 - 1/64.6)

-2.3 =  -ΔHvap/8.314(0.066 - 0.015)

-2.3 =  -0.051ΔHvap/8.314

ΔHvap = -2.3  * 8.314/ -0.051

ΔHvap = 374.9 J/mol

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465 grams of sugar If so, 300 grams of water ought to be able to tell you 3*155 grams of sugar. In 300 grams of water, there are 465 grams of sugar (3 x 155).

Traditionally, the dissolve editing method is used to segue between images that link two scenes together. Instead of a direct cut from one shot to the next, a dissolve gradually transitions from one image to the next.

Salt, sugar, and coffee are among the things that can dissolve in water. These objects disintegrate. Usually, they dissolve more easily and fast in warm or hot water. In hot water, but not at room temperature, sand and pepper are soluble.

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Diagram 2 best represents the speed of the particles of a gas at a fixed temperature because the particles have a variety of different speeds.

What is speed?

In everyday use and kinematics, the velocity of an object (commonly denoted by v) is the rate of change of position over time, or the rate of change of position per unit time. So it's a scalar quantity. The average velocity of an object within a time interval is the distance traveled by the object divided by the duration of the interval [2] The instantaneous velocity is the limit of the average velocity as the duration of the time interval approaches zero. Velocity is not the same as speed.

Velocity is the dimension of distance divided by time. The SI unit for speed is meters per second (m/s), but the most common everyday speed units are kilometers per hour (km/h) or miles per hour (mph) in the US and UK. ). Knots are widely used in air and sea travel.

Diagram 2 best represents the speed of the particles of a gas at a fixed temperature because the particles have a variety of different speeds.

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Look below. When two amino acids are joined together, or when two amino acids condense, a dipeptide is created. Condensation occurs between the amine group of one amino acid and the acid group of another.

What is the photosynthesis chemical formula?

The carboxyl group on one amino acid and the amino group on the other combine to create a link, which results in the creation of a water molecule. What do you name a dipeptide that has been split into two amino acids?

The dipeptide is broken down into two ionised amino acids in the hydrolysis reaction depicted here with the addition of a water molecule. One amino acid receives a negative charge and an oxygen atom, whereas the second amino acid receives two hydrogen atoms.

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The product of the -4 4-3 H-50 Li And And H = Li And _O, And I © Li is the diagram in option B.

One or more hydrogen ions, H+, are exchanged between species that may be neutral (molecules, such as water, H2O), or electrically charged (ions, such as ammonium, NH4+, hydroxide, OH, or carbonate, CO32), in an acid-base process.

The hydroxide of acid and metal for acid and metal neutralization. Oxide of metal and acid. A neutralizing reaction occurs when an acid and a base interact. This reaction yields a salt and water as byproducts.

Therefore, the correct option is B.

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The question is incomplete. Your most probably complete question is given below: the image of the options is added.

Instead, Cupid fell in love with Psyche and married her just on condition that she would never see him face.

Venus, a goddess of love, is the mother of Cupid in Roman mythology.He was the son to Aphrodite and was known by the Greek name Eros.In spite of his mother's jealousy over Psyche's beauty, Cupid reportedly fell deeply in love with her.

According to one story, Cupid had a partner by the name of Psyche who lived a very lonely existence because no other women liked her and no male gods were interested in her until she found Eros.

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The largest buffering capabilities of monoamino monocarboxylic acids are found in the two pH ranges closest to their two pK′ values, namely pH 2.3 and pH 9.7.

Buffer capacity measures a solution's ability to tolerate pH fluctuations by either absorbing or desorbing H+ and OH- ions. The effect of adding an acid or base to a buffer system on pH change can be considerable or modest, depending on both the starting pH and the buffer's ability to resist pH change.

A good buffer combination should include roughly equal amounts of both components. As a general rule, a buffer solution is no longer helpful when one component of the buffer pair is less than around 10% of the other.

If the buffer capacity is increased by tenfold, the buffer solution may absorb ten times more strong acid or base before experiencing a noticeable pH shift. When an acid or basic is introduced to a solution, a buffer maintains a reasonably constant pH.

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Each molecule of water contains 2 H and 1 O atom = 3 atoms, so there are approximately [tex]1.8 * 10^{24}[/tex] atoms in a mole of water.

In the International System of Units, the mole (symbol mol) is the unit of substance amount (SI). The amount of substance is a measurement of how many elementary entities of a given substance are present in an object or sample.

An elementary entity can be an atom, a molecule, an ion, an ion pair, or a subatomic particle such as an electron, depending on the substance. For example, despite having different volumes and masses, 10 moles of water (a chemical compound) and 10 moles of mercury (a chemical element) contain equal amounts of substance, and the mercury contains exactly one atom for each molecule of water.

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Cooking temperature can reach above 150 degrees F kill salmonella. Salmonellosis is caused primarily by contaminated cooked foods as well as insufficient cooking. Contamination of prepared meats occurs as a result of contact with unwashed surfaces or utensils after use with raw material.

Salmonellosis is an infectious disease caused by the bacteria Salmonella, which lives in the intestines of animals, which include birds. Salmonella is typically transmitted to humans through the consumption of foods heavily polluted with animal feces. In the United States, approximately 40,000 incidents of salmonellosis have been reported each year.

Salmonella bacteria enter the body through the stomach as well as colonize the large and small intestines after being consumed. Bacteria infiltrate and multiply in the intestinal mucosa. Bacteria can enter the gastrointestinal tract's lymphoid tissues and spread to the blood system.

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Lewis structure for CI4 is finding the total amount of valence electrons is the first step.

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An atom having principal quantum number, n = 3 can have a maximum of :2n²= 2(3)²=18  electrons

Principal quantum number denotes the energy and size of the orbital. It is represented by the symbol "n". It can have positive values viz. 1,2,3,4,5...,etc. The orbitals having the same value of principal quantum number forms a shell.

In a given atom, for a shell having principal quantum number "n", the maximum number of electrons that can be occupied is 2n².

Out of these electrons, half of them will have principal quantum number -1/2 and other half will have +1/2.

So, when n=3 , out of 18 electrons, 9 electrons will have spin quantum number -1/2 and rest 9 electrons will have spin quantum number +1/2.

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The hybridization of the carbon atom that is double bonded to an oxygen atom is: A. sp.

To determine the hybridization of an atom in a molecule, we can follow these steps:

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Anode in a bath of molten cryolite heated to between 950 and 1000 °C is part of an electrolytic reduction cell for the manufacture of metal.

The Faraday constant F represents the charge of a mole of electrons (96485 C/mol), and since each mole of water requires two moles of electrons, the minimum voltage required for electrolysis is roughly 1.23 V. This voltage decreases when electrolysis is performed at a high temperature.

Therefore, during electrolysis, the rate of the reaction increases as voltage is raised. The nature and material of the electrode, the presence of oxidizing and reducing chemicals in the electrolyte, and electrode potential are the parameters that affect the electrolysis process.

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Answer:

Atomic theory

Explanation:

The atomic model is a representation of the atom.

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