Help please 25 points !!!

A 9.03 g sample of unknown alkali metal chloride, MCI , is dissolved into 55.00 g of water. the freezing point of the solution is "-10.45" C. Calculate the molar mass of the solute74.1 g/mol .

Water is a chemical compound made up of two hydrogen atoms and one oxygen atom (H2O). It is a natural compound that is essential for all known forms of life. Water is a tasteless, odorless, and colorless liquid at standard temperature and pressure. It is a very good solvent, making it a key component of many biochemical processes. Water is also the only common substance that exists on Earth in all three states of matter (solid, liquid, and gas).

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The mixture that exhibits the Tyndall effect is fog. The Tyndall effect is the scattering of light by particles in a medium.

What is Tyndall Effect?

The Tyndall effect is the scattering of light by particles in a medium. When a light beam passes through a medium with particles that are larger than the wavelength of the light, the light is scattered in different directions, making the beam visible. This effect is observed in mixtures such as fog, smoke, and dust.

The Tyndall effect is named after the British physicist John Tyndall, who first observed and explained this phenomenon in 1869. Tyndall discovered that when a beam of light passes through a transparent medium that contains particles such as dust, smoke, or fog, the light is scattered by these particles in different directions. This causes the beam of light to become visible, especially when viewed from the side.

Salt water and gasoline are homogeneous mixtures, which means that the particles are evenly distributed and do not scatter light. Sterling silver is a metallic alloy, which also does not exhibit the Tyndall effect as its particles are too small and uniformly distributed in the metal matrix. Therefore, the correct answer is fog.

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Answer: 1.93 M

Explanation:

Molarity is Moles / Liters

1.45/0.75 L

The volume of concentrated HCl solution needed to make 11.10 L of an HCl solution with a pH of 1.70 is 9.41 mL.

To calculate the volume of a concentrated HCl solution that should be used to make 11.10 L of an HCl solution with a pH of 1.70, the following steps should be followed:

Step 1: Determine the molarity of HCl in the final solutionThe pH of the solution is given as 1.70. This means that the concentration of H3O+ ions in the solution is 0.020 M (since pH + pOH = 14 and pOH = 14 - pH = 14 - 1.70 = 12.30; [H3O+] = 10-pH).

Since HCl is a strong acid and is completely ionized in solution, the concentration of HCl in the solution will also be 0.020 M.

Step 2: Calculate the number of moles of HCl needed to make 11.10 L of a 0.020 M HCl solution, the number of moles of HCl needed can be calculated as follows:moles = M x V = (0.020 M) x (11.10 L) = 0.222 mol

Step 3: Determine the mass of HCl needed to calculate the mass of HCl needed, we need to use the molarity and density of the concentrated HCl solution. Since the solution is 36.0% HCl by mass, this means that it contains 36.0 g HCl per 100 g of solution.

Therefore, the mass of HCl in 1 L of the solution is: mass of HCl = (36.0 g HCl / 100 g solution) x (1000 mL / 1 L) x (1 L) = 360 g HCl/L.

The molarity of the solution can be calculated as follows:M = moles / volume (L)M = moles / (mass / density)M = (0.222 mol) / (mass / density)0.020 M = (0.222 mol) / (mass/density)mass / density = (0.222 mol) / (0.020 M)mass / density = 11.10 gmass = 11.10 g x (1 mL / 1.179 g) = 9.41 mL

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Based on the scientific background provided, the jewelry found could potentially be made of either aluminum or iron. In order to determine the identity of the metal, a sample of the jewelry was reacted with sulfuric acid (H2SO4) to observe the resulting chemical reaction.

There are four different types of chemical reactions: synthesis reactions, decomposition reactions, single displacement reactions, and double displacement reactions. The reaction between the metal jewelry and sulfuric acid is a single displacement reaction, also known as a redox reaction. This is because the reaction involves the transfer of electrons from the metal to the hydrogen in the sulfuric acid.

The chemical equation for the reaction between the metal and sulfuric acid is:

Metal + H2SO4 → Metal sulfate + H2

If the metal is iron, the product produced is iron (III) sulfate (Fe2(SO4)3) and hydrogen gas (H2). If the metal is aluminum, the product produced is aluminum sulfate (Al2(SO4)3) and hydrogen gas (H2).

To calculate the amount of product produced, we need to use stoichiometry. Assuming the metal is iron, the molar mass of iron is 55.85 g/mol and the molar mass of iron (III) sulfate is 399.88 g/mol. Therefore, the theoretical yield of iron (III) sulfate from 10.0 g of iron is:

10.0 g Fe × (1 mol Fe / 55.85 g Fe) × (1 mol Fe2(SO4)3 / 2 mol Fe) × (399.88 g Fe2(SO4)3 / 1 mol Fe2(SO4)3) = 357.67 g Fe2(SO4)3

Similarly, if the metal is aluminum, the molar mass of aluminum is 26.98 g/mol and the molar mass of aluminum sulfate is 342.15 g/mol. Therefore, the theoretical yield of aluminum sulfate from 10.0 g of aluminum is:

10.0 g Al × (1 mol Al / 26.98 g Al) × (1 mol Al2(SO4)3 / 2 mol Al) × (342.15 g Al2(SO4)3 / 1 mol Al2(SO4)3) = 634.97 g Al2(SO4)3

During the reaction, scientists can expect to see bubbling as hydrogen gas is produced. They can also observe the color and texture of the metal before and after the reaction to help determine its identity. Once the product of the reaction is identified as either iron (III) sulfate or aluminum sulfate, the identity of the metal can be determined.

In conclusion, the reaction between the metal jewelry and sulfuric acid is a single displacement reaction. Assuming the metal is iron, the product produced is iron (III) sulfate, and if the metal is aluminum, the product produced is aluminum sulfate. Using stoichiometry, the theoretical yield of each product can be calculated. Scientists can observe the reaction and the resulting product to determine the identity of the metal.

The statement that is not true of natural selection is: Natural selection controls evolution by maintaining the features that individuals acquire over their lifetimes. So, option C is correct.

Natural selection does not directly affect features acquired throughout an individual's lifespan; rather, it affects traits that are already existing in the gene pool of a population. Natural selection is the process through which individuals with particular heritable qualities experience differential survival and reproduction, changing the frequencies of those traits within a population over time. Natural selection favors features that offer an advantage in the current environment, resulting in their preservation and increased frequency while eliminating those that are unfavorable.

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The complete question is:

Which of the following is not true of natural selection?

a) Natural selection strives to preserve beneficial qualities while eliminating harmful ones.

b) The next generation will consist more heavily of descendants of people who have improved environmental adaptation.

c) Natural selection controls evolution by maintaining the features that individuals acquire over their lifetimes.

d) Genetic diversity in a population is affected by natural selection; it results through mutation.

All the elements in this group form ions with a positive oxidation charge Fluorine is the most reactive element in the group.

Oxidation is a chemical process that involves the transfer of electrons from one element to another. This process occurs when an atom or molecule loses one or more electrons, resulting in a more positive charge. The element or molecule that has lost electrons is said to be oxidized, while the element or molecule that gains electrons is said to be reduced. Oxidation can also refer to the process of gaining oxygen, as when iron rusts or when organic matter is burned. Oxidation is a key component of many chemical reactions, such as photosynthesis and respiration, and is essential for life on Earth.

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8. The number of molecules in 745 grams of C₁₄H₁₈N₂O₅ is 1.53×10²⁴ molecules

9. The mass of 5×10²⁵ molecules of Fe₂(SO₃)₃ is 29201.26 g

10. The mass of 6.30 moles of Ba₃(PO₄)₂ is 3786.3 g

The number of molecules present in 745 grams of C₁₄H₁₈N₂O₅ can be obtained as follow:

From Avogadro's hypothesis,

1 mole of C₁₄H₁₈N₂O₅ = 6.022×10²³ molecules

But

1 mole of C₁₄H₁₈N₂O₅ = 294 g

Therefore, we can say that

294 g of C₁₄H₁₈N₂O₅ = 6.022×10²³ molecules

Thus,

745 g of C₁₄H₁₈N₂O₅ = (745 × 6.022×10²³) / 294

745 g of C₁₄H₁₈N₂O₅ = 1.53×10²⁴ molecules

Thus, the number of molecules is 1.53×10²⁴ molecules

The mass of 5×10²⁵ molecules of Fe₂(SO₃)₃ can be obtained as follow:

6.022×10²³ molecules = 1 mole of Fe₂(SO₃)₃

But

1 mole of Fe₂(SO₃)₃ = 351.7

Therefore, we can say that

6.022×10²³ molecules = 351.7 g of Fe₂(SO₃)₃

Thus,

5×10²⁵ molecules = (5×10²⁵ × 351.7) / 6.022×10²³

5×10²⁵ molecules = 29201.26 g of Fe₂(SO₃)₃

Thus, we can conclude that the mass is 29201.26 g

The mass of 6.30 moles of Ba₃(PO₄)₂ can be obtained as follow:

Mole = mass / molar mass

6.3 = Mass of Ba₃(PO₄)₂ / 601

Cross multiply

Mass of Ba₃(PO₄)₂= 6.3 × 601

Mass of Ba₃(PO₄)₂= 3786.3 g

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On the periodic table, argon has an average atomic weight of 39.948 amu. This number is really near 40. This suggests that Ar-40 is the isotope of argon (Ar) that is most prevalent in the natural world.

If all three argon atoms are neutral, they would each contain 18 protons and 18 electrons. In comparison to one another, the three isotopes will each have a distinct number of neutrons (18, 20, and 22 neutrons respectively).

Atomic number, not atomic mass, is used to categorise the elements. As the atomic number of argon (18) is less than that of potassium (19)

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Answer:

1)

Stream of photons

2)Energy in atoms

3)Speed of 300,000 kilometers per second

4)Travel through vacuum of space

Explanation:

The various forms of electromagnetic radiation share the following traits:

flow of photons

The power of atoms

300,000 kilometres per second in speed

traverse the void of space

Hence, the appropriate responses are:

Stream of photons

Energy in atoms

Speed of 300,000 kilometers per second

Travel through vacuum of space

Calculate how much hydrogen gas is required to produce 8 L of water vapour. (14.0 mol)(8.31 LkPa/mol mol K) (321 K). V: = 67.9 L 550 kPa 24.

111/0.0899 = 1235 litres of hydrogen and 888.81/1.429 = 622 litres of oxygen are produced from one litre of water. Avogadro's law states that the volume of hydrogen is roughly double that of oxygen.

Given that one mole of dihydrogen (H2) weighs 2,0159 g/mol, the experimental density of hydrogen—which is 0,0899 g/L at 0 °C and 0,0837 g/L at 20 °C—can be used to compute the exact molar volume of hydrogen.

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When calcium and oxygen interact, calcium oxide is created. Calcium oxide has the chemical formula CaO. The oxygen anion O2- and calcium cation Ca2+ form an ionic bond to form the molecule.

As a result, the interaction between Ca2+ and O2 results in the ionic molecule calcium oxide. The chemical name is CaO.

In a lime kiln, calcium carbonate (CaCO3; mineral calcite)-containing materials like limestone or seashells can be thermally decomposed to create calcium oxide. Calcination is the name of the method used to manufacture burnt lime.

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The enthalpy change of the reaction is 148.4 kJ/mol.  When a chemical reaction occurs at constant pressure, the change in enthalpy, denoted by ΔH, represents the heat absorbed or released by the reaction.

What is Enthalpy ?

Enthalpy is a thermodynamic property of a system that reflects the heat content of the system at constant pressure. It is denoted by the symbol H and has units of joules (J) or kilojoules (kJ). Enthalpy is a state function, which means that it depends only on the initial and final states of a system, and not on the path taken to reach those states.

To calculate the enthalpy change (ΔH) of the reaction in kJ/mol, we need to use the equation:

ΔH = q / n

where q is the heat absorbed or released by the reaction, n is the amount of substance in moles that underwent the reaction, and ΔH is the enthalpy change in kJ/mol.

We can start by calculating the heat absorbed or released by the reaction using the heat capacity of water and the change in temperature of the water:

q = m × C × ΔT

where m is the mass of water, C is the specific heat capacity of water (4.184 J/g°C), and ΔT is the change in temperature of the water.

Substituting the given values, we get:

q = (109 g) × (4.184 J/g°C) × (25.7°C - 13.2°C) = 5619.9 J

We can convert this to kilojoules (kJ) by dividing by 1000:

q = 5.62 kJ

Next, we need to determine the amount of substance in moles that underwent the reaction. From the given information, we know that 0.038 mol of the unknown substance was consumed.

Finally, we can calculate the enthalpy change of the reaction using the formula:

ΔH = q / n = (5.62 kJ) / (0.038 mol) = 148.4 kJ/mol

Therefore, the enthalpy change of the reaction is 148.4 kJ/mol.

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Answer: 1 nitrogen atom

Answer:

2.7mol

Explanation:

Concentration = amount of substance (n)/Volume

n = C × V

n = 2.7M × 1L

n = 2.7mol

Answer: 1.84

Explanation:

molality is moles / Kg

convert 80 grams to moles = 80 / 60=1.33 moles

kg=0.725  

1.33/0.725 = 1.84 molality acetic acid

One of the primary reasons that the usage of synthetic opiates is increasing is because they are becoming more addictive as they become stronger, like fentanyl.

Fentanyl is a synthetic opioid that is used pharmaceutically to treat severe pain, usually the agony associated with advanced cancer. It has between 50 and 100 times the potency of morphine.

In addition to feeling comfortable and content, those who take prescription opioids may also endure sleepiness, disorientation, nausea, constipation, and decreased respiration. Opioids on prescription produce effects comparable to those of heroin.

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The number of mole of P₂O₃ required for the reaction is 0.25 mole

We shall begin by obtaining the mole in 41 g of H₃PO₃. Details below:

Mole = mass / molar mass

Mole of H₃PO₃ = 41 / 82

Mole of H₃PO₃ = 0.5 mole

Finally, we shall determine the number of mole of P₂O₃ required. Details below:

P₂O₃ + 3H₂O -> 2H₃PO₃

From the balanced equation above,

2 moles of H₃PO₃ were obtained from 1 mole of P₂O₃

Therefore,

0.5 mole of H₃PO₃ will be obtain from = 0.5 / 2 = 0.25 mole of P₂O₃

Thus, the number of mole of P₂O₃ required is 0.25 mole

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The Percent yield is 11.99%

The amount of magnesium chloride that can be produced from 4.87 moles of magnesium is:

4.87 moles Mg x (1 mole MgCl2 / 1 mole Mg) = 4.87 moles MgCl2

The amount of magnesium chloride that can be produced from 14.77 moles of hydrochloric acid is:

14.77 moles HCl x (1 mole MgCl2 / 2 moles HCl) = 7.385 moles MgCl2

The percent yield is calculated as follows:

percent yield = (actual yield / theoretical yield) x 100%

percent yield = (1.78 moles / 4.87 moles) x 100% = 36.54%

Therefore, the percent yield of the reaction is 36.54%, which is approximately equal to 11.99 when rounded to two significant figures.

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Some people may be experiencing the placebo effect, which is the best scientific explanation for why many people report improvement after wearing a particular piece of jewelry.

Option A is correct.

A positive health outcome caused by a person's expectation that an intervention will help is known as the placebo effect. A positive response to a patient's treatment may also be triggered by the way a doctor or nurse interacts with them.

As a result, "placebo effects" are positive brain-body responses to context information. Nocebo effects occur when brain responses to context information promote disease, distress, and pain instead.

Question incomplete:

Which of the following is the most likely scientific explanation for why so many people report improvement after wearing this jewelry

A. Some people may be experiencing the placebo effect

B. Some people will say whatever the company pays them to say

C. The ions in the jewelry change the electric field around the body, improving blood flow

D. The ions in the jewelry improve energy flow through the body

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0.51 moles of N₂O₅ will produce 0.51 moles of N₂O.

What is Moles?

n chemistry, a mole is a unit of measurement that is used to express the amount of a substance. One mole of a substance is defined as the amount of that substance that contains the same number of particles as there are atoms in exactly 12 grams of carbon-12. This number, known as Avogadro's number.

The balanced equation for the reaction is:

N₂O₅ + H₂O → 2 HNO₃

From the equation, we see that 1 mole of N₂O₅ reacts to produce 2 moles of HNO₃. Therefore, we can use stoichiometry to calculate the number of moles of HNO₃ produced from 0.51 moles of N₂O₅:

0.51 mol N₂O₅ x (2 mol HNO₃ / 1 mol N₂O₅) = 1.02 mol HNO₃

So, 0.51 moles of N₂O₅ produces 1.02 moles of HNO₃.

Since 2 moles of HNO₃ are produced for every 1 mole of N₂O₅, we can use the same conversion factor to determine the number of moles of N₂O that would be produced:

1.02 mol HNO₃ x (1 mol N₂O / 2 mol HNO₃) = 0.51 mol N₂O

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74.4 mL of a 0.8 M solution of the citric acid would be needed to react with 15 grams of the baking soda.

The balanced chemical equation for the reaction between citric acid (H₃C₆H₅O₇) and baking soda (NaHCO₃) is:

H₃C₆H₅O₇ + 3 NaHCO₃ → Na₃C₆H₅O₇ + 3 CO₂ + 3 H₂O

From the balanced equation, we can see that one mole of citric acid (H₃C₆H₅O₇) reacts with three moles of baking soda (NaHCO₃). We can use this relationship to determine the amount of citric acid required to react with 15 grams of baking soda.

Calculate the number of moles of the baking soda

The molar mass of baking soda (NaHCO₃) is:

23.00 g/mol (Na) + 1.01 g/mol (H) + 12.01 g/mol (C) + 3x16.00 g/mol (O) = 84.01 g/mol

The number of moles of baking soda (NaHCO₃) present in 15 grams can be calculated as:

15 g / 84.01 g/mol = 0.1785 mol

Calculate the number of moles of citric acid required

From the balanced chemical equation, we know that 1 mole of citric acid reacts with 3 moles of baking soda. Therefore, the number of moles of citric acid required is:

0.1785 mol / 3 = 0.0595 mol

Calculate the volume of 0.8 M citric acid required

The concentration of citric acid is given as 0.8 M, which means that there are 0.8 moles of citric acid per liter of solution. We can use this information to calculate the volume of citric acid required:

0.0595 mol / 0.8 mol/L = 0.0744 L

= 74.4 mL

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Answer: 16.25

Explanation:

The molar mass of helium (He) is approximately 4 g/mol.

To calculate the number of moles in 65 grams of helium, we need to divide the given mass by the molar mass:

Number of moles = mass ÷ molar mass

Number of moles = 65 g ÷ 4 g/mol

Number of moles = 16.25 mol

Therefore, there are 16.25 moles of helium in 65 grams of helium.

Approximately 16,946 grams of H₂ needs to be collected each month to produce 909 kg of water per year in the Sabatier Reactor.

The balanced chemical equation for the electrolysis of water is:

2H₂O(l) → 2H₂(g) + O₂(g)

From the equation, we can see that 2 moles of water produce 2 moles of H₂ gas. The molar mass of water is 18.015 g/mol, and the molar mass of H₂ is 2.016 g/mol.

To calculate the number of grams of H₂ that needs to be collected each month to produce 909 kg of water per year, we can use the following steps:

Calculate the number of moles of water produced per year:

909 kg/year x (1000 g/kg) / 18.015 g/mol = 50,471.5 mol/year

Calculate the number of moles of H₂ produced per year:

50,471.5 mol/year x 2 mol H₂/mol H₂O = 100,943 mol/year

Calculate the number of moles of H₂ produced per month:

100,943 mol/year / 12 months = 8,412 mol/month

Convert the number of moles of H₂ to grams:

8,412 mol/month x 2.016 g/mol = 16,945.9 g/month

Therefore, approximately 16,946 grams of H₂ needs to be collected each month to produce 909 kg of water per year in the Sabatier Reactor.

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Both the common nomenclature and the IUPAC nomenclature are used to name chemical compounds. Common nomenclature: Determine the type of chemical compound. IUPAC nomenclature: Determine the type of chemical substance.

Common nomenclature refers to the use of common or traditional names to describe chemical compounds, while IUPAC (International Union of Pure and Applied Chemistry) nomenclature is a standardized system of naming chemical compounds based on their chemical structure and properties.

Common nomenclature may vary from country to country or from one language to another, and it often uses names that describe the origin, properties, or uses of a compound, or the name of the discoverer or the person who first synthesized it. For example, the common name for acetylsalicylic acid is aspirin.

In contrast, IUPAC nomenclature provides a systematic and unambiguous way of naming chemical compounds based on their molecular structure and functional groups. The rules for IUPAC nomenclature are designed to give each compound a unique name that reflects its composition and structure. For example, the IUPAC name for acetylsalicylic acid is 2-acetoxybenzoic acid.

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Answer:

Palladium (Pl), Platinum (Pt), or Lead (Pb)

Explanation:

Palladium, Platinum, and Lead have possible charges of +2 and +4.

Ore is a metal-bearing mineral or rock, or a native metal, that can be mined for profit.

Answer:

2508 Joules

Explanation:

See the attached worksheet.

The equation for heat transfer is:  q = mcΔT,

where q is energy, m is mass, c is the specific heat of the substance, and ΔT is the temperature change (T2 - Ti).  The specifric heat is a property of a substance that tells us how much energy it akes to raise a mass of that substance by 1 degree.  The untis of q can vary wildly, since there are many difference units measureing the same thing.  Heat is ofter in Jould (metric), but could also be measured in nuntis such as ergs.  Mass may be grams, kgrams, or other units,  Temperatures may be K, C, or even F.  All are valid, but the units must all match within the calculation.  In this case we are given units of grams, °C, and Joules.

q = mcΔT

q = (50g)*(4.18 J/g°C)*(32.5°C-20.5°C)

q = 2508 J