A common laboratory reaction is the neutralization of an acid with a base. When 31.8 mL of 0.500 M HCl at 25.0°C is added to 68.9 mL of 0.500 M NaOH at 25.0°C in a coffee cup calorimeter (with a negligible heat capacity), the temperature of the mixture rises to 28.2°C. What is the heat of reaction per mole of NaCl (in kJ/mol)? Assume the mixture has a specific heat capacity of 4.18 J/(g·K) and that the densities of the reactant solutions are both 1.07 g/mL. Enter your answer to three significant figures in units of kJ/mol.

Answer:

301.15 K

Explanation:

while zinc is an important mineral with numerous functions in the body, it is not true that grains are the most reliable food source of zinc. A balanced diet that includes a variety of foods can provide adequate zinc intake for most people.

How to solve the problem?

The statement that is NOT true of zinc is "Grains are the most reliable food sources of zinc." While grains can be a source of zinc, they are not necessarily the most reliable source.

Zinc is an essential mineral that plays important roles in many biological processes, including immune function, protein synthesis, wound healing, and DNA synthesis. It is involved in various enzymatic reactions, and acts as a cofactor for many enzymes. Zinc is also important for proper growth and development, especially during childhood and adolescence.

Excess zinc intake can lead to decreased copper absorption, as both minerals compete for absorption in the intestines. This can lead to copper deficiency, which can cause anemia neutropenia, and other health problems. Therefore, it is important to maintain a balance between zinc and copper intake.

While grains can be a source of zinc, other foods such as meat, seafood, and dairy products are also good sources. Vegetarians and vegans may need to pay particular attention to their zinc intake, as plant-based sources of zinc may be less bioavailable than -based sources. Zinc supplements can also be used to prevent or treat deficiencies, but should be used with caution as excessive intake can have negative health effects.

In summary, while zinc is an important mineral with numerous functions in the body, it is not true that grains are the most reliable food source of zinc. A balanced diet that includes a variety of foods can provide adequate zinc intake for most people.

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Explanation:  C) the air temp. at the top is lower

The volume of the gas at STP would be 23.93 liters.

The volume of gas at STP (Standard Temperature and Pressure), we need to use the Ideal Gas Law, which states that PV = nRT, where P is pressure, V is volume, n is the number of moles of gas, R is the gas constant, and T is temperature. First, we need to calculate the number of moles of gas in the initial sample. We can use the formula n = PV/RT, where P is the initial pressure, V is the initial volume, R is the gas constant, and T is the initial temperature.
n = (2.31 atm) x (25.15 L) / [(0.0821 L atm/mol K) x (201 + 273.15 K)]
n = 1.067 moles

Now, we can use the molar volume of gas at STP, which is 22.4 L/mol, to calculate the volume of gas at STP.
V = n x 22.4 L/mol
V = 1.067 moles x 22.4 L/mol
V = 23.93 L
Therefore, the volume of the gas at STP would be 23.93 liters.

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Sorry so what I think u should do is ask your teach or look up on how to do this problem

The 2 isotopes of Nitrogen are Nitrogen-14  and Nitrogen-15 .

Isotopes are atoms with the same number of protons and different number of neutrons. Even though they have nearly identical chemical properties, they differ in mass which affects their physical properties.

As you know, the atomic number of nitrogen is = 7.

Isotopes are forms of elements that have the same atomic number (Z) but different mass numbers because they have different numbers of neutrons (A).

Now,

Atomic number = number of protons

Isotopes have the same atomic number.

Atomic number for both isotopes = 7. However, the mass numbers of the two isotopes are different.

In other words, the mass number = the number of (protons + electrons).

Therefore, nitrogen-14 has a mass number of 14 and nitrogen-15 has a mass number of 15.

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Answer:

it is outside the nucleus  F

it has a positive charge  T

it has no mass  F

it has a negative charge  F

it is inside the nucleus  ...it is part OF the nucleus.

it is the same as the atomic number  T

it is the same as the number of neutrons  F

75% of the isotopes have a mass ima just guess cuz i dunno about this one...i think it matters on the atom element.

Explanation:

Answer:

A chromosome is a thread-like structure present in the nucleus  that is made up of a single molecule of DNA and proteins, carrying some or all genetic materials of an organism. A chromatid is an identical half of a duplicated chromosome

Explanation:

The Orion constellation which can be seen all around the world is positioned upon its celestial equator and it is among the noticeable and distinctive constellations in the sky. It is thought to be a Greek Mythology named after a hunter.

The Orion Nebula forms from dust, hydrogen as well as other ionized gases.

The tale and myth of Orion have various variations and explanations but one of the most popular ones is that Orion declared himself as the topmost and strongest hunter in the world.

Therefore, we can conclude that the constellation Orion made using a telescope are Myth.

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Answer:

The density of water is 1g/mL

Answer:

d=m/

Explanation:

d is density, m is mass, v is volume

Given: m =10.4g, v=12.2mL

substituting in equation,

d=10.4/ 12.2

d=0.8524g/mL

To learn more about density:

The density of the liquid is 0.852 g/mL.

To calculate the density of the liquid, we need to use the formula:

Density = Mass / Volume

Given that the mass of the liquid is 10.4 g and the volume is 12.2 mL, we can substitute these values into the formula:

Density = 10.4 g / 12.2 mL

Simplifying this expression, we find:

Density = 0.852 g/mL

Density is a physical property of a substance and is defined as the amount of mass per unit volume. In this case, the density tells us that for every milliliter of the liquid, there is 0.852 grams of mass. The units of grams per milliliter (g/mL) indicate that the density is a ratio of mass to volume.It is important to note that the density of a substance can vary with temperature, so this value is only valid under the conditions at which the measurement was made. Additionally, the density can provide valuable information about the identity of a substance, as different substances have different densities.

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Types of luminous flames:

1. Yellow Luminous Flame

2. Smoky Luminous Flame

3. Orange Luminous Flame

4. Blue Luminous Flame

Luminous flames are characterized by their visible glow, which is caused by the incomplete combustion of fuel. The presence of soot particles in the flame causes the emission of light. There are different types of luminous flames, which can be classified based on their fuel composition and burning conditions. Here are some common types of luminous flames:

1. Yellow Luminous Flame: This is the most common type of luminous flame, often seen in open fires, candles, and gas stoves. It appears yellow due to the presence of soot particles in the flame. Yellow flames indicate incomplete combustion of hydrocarbon fuels, such as methane, propane, or natural gas. The high carbon content in these fuels leads to the formation of soot, which emits visible light.

2. Smoky Luminous Flame: This type of flame is characterized by a significant amount of black smoke and soot production. It is commonly observed in poorly adjusted or malfunctioning burners or engines. The excessive presence of unburned fuel in the flame results in incomplete combustion and the emission of dark smoke particles.

3. Orange Luminous Flame: An orange flame indicates a higher combustion temperature compared to a yellow flame. It is often seen in more efficient burners or when burning fuels with a higher carbon content, such as oil or diesel. The higher temperature helps in burning more of the carbon particles, reducing the amount of soot and making the flame appear less yellow.

4. Blue Luminous Flame: A blue flame is typically associated with complete combustion. It indicates efficient burning of fuel, resulting in minimal soot formation. Blue flames are commonly observed in gas burners or Bunsen burners. The blue color is a result of the combustion of gases, such as methane, in the presence of sufficient oxygen.

It's important to note that the luminosity of a flame can vary depending on factors such as fuel-air mixture, combustion temperature, and the presence of impurities. Achieving complete combustion and minimizing the production of soot is desirable for efficient and cleaner burning processes.

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it's helpful

you can try this answer

Like charges repel each other, while opposite charges attract each other. This principle is one of the fundamental aspects of electrostatics. According to Coulomb's law, the force between two charged particles is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

As the distance between two charged particles decreases, the force between them increases. This is because the closer the particles are, the stronger the electric field they create, leading to a stronger force of interaction.

On the other hand, as the magnitude of the charges decreases, the force between the particles also decreases. This is because the force is directly proportional to the product of the charges. If one or both of the charges are smaller, the force they exert on each other will be weaker.

In summary, according to Coulomb's law, decreasing the distance between charged particles increases the force between them, while decreasing the magnitude of the charges decreases the force. This understanding of the relationship between charge, distance, and force is crucial in explaining the behavior of charged particles and the interactions between them.

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Phosphatidylserine is a type of phospholipid that is mainly found in cell membranes. Its structure is made up of two fatty acid chains, a phosphate group, a serine molecule, and a glycerol molecule.

The fatty acid chains are hydrophobic, meaning they repel water, while the phosphate group and serine molecule are hydrophilic, meaning they attract water.

The glycerol molecule acts as a bridge that connects the two fatty acid chains to the phosphate group and serine molecule.
The structure of phosphatidylserine is important for its function in the cell membrane.

Because of the hydrophobic and hydrophilic components of its structure, phosphatidylserine is able to form a lipid bilayer, which is a barrier that separates the inside of the cell from the outside environment.

The hydrophilic heads of the phosphatidylserine molecules face outward and interact with water, while the hydrophobic tails face inward and repel water.
Phosphatidylserine also plays a role in cell signaling and apoptosis, which is programmed cell death.

It acts as a signaling molecule by binding to proteins that are involved in cellular pathways.

In addition, phosphatidylserine is translocated to the outer leaflet of the cell membrane during apoptosis, which signals to immune cells that the cell is ready to be removed.
In conclusion, the structure of phosphatidylserine is made up of two fatty acid chains, a phosphate group, a serine molecule, and a glycerol molecule. Its hydrophobic and hydrophilic components allow it to form a lipid bilayer in cell membranes, and it also plays a role in cell signaling and apoptosis.

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Answer:

1) Element is a pure substance consisting only of atoms that all have the same numbers of protons in their nuclei.

2) a) Element is a pure substance

  b) It is homogeneous

3) Bromine

4) Elements and compounds are pure chemical substances found in nature. The difference between an element and a compound is that an element is a substance made of same type of atoms, whereas a compound is made of different elements in definite proportions. Examples of elements include iron, copper, hydrogen and oxygen.

5) The law of definite proportions

Explanation:

This is all i know, bro

Answer:

C. To determine how efficient reactions are.

D. To determine how much reactant they need.

Explanation:

When you are doing a reaction, you are hoping for a percent yield to close of 100%. You make the reaction and determine how many product you obtain. If you know the percent yield of a reaction you can calculate the amount of reactant you need to obtain a determined amount of product.

Having this in mind:

A. To balance the reaction equation.  false. To calculate percent yield you need to balance the reaction before. You don't use percent yield to balance the reaction

B. To determine how much product they will need.  false. You determine how much product you obtain after the reaction. How much product you need is independent of percent yield

C. To determine how efficient reactions are.  true. A way to determine efficience of a reaction is with percent yield. An efficient reaction has a high percent yield.

D. To determine how much reactant they need. true. If you know percent yield of a reaction you can know how many reactant you must add to obtain  the amount of product you want.

Answer:

The heat and pressure can rearrange the minerals in the rocks

Answer:

+1

Explanation:

Na₂O₂

NOTE: the oxidation number of oxygen is always –2 except in peroxides where it is –1.

Thus, we can obtain the oxidation number of sodium (Na) in Na₂O₂ as illustrated below:

Na₂O₂ = 0 (oxidation number of ground state compound is zero)

2Na + 2O = 0

O = –1

2Na + 2(–1) = 0

2Na – 2 = 0

Collect like terms

2Na = 0 + 2

2Na = 2

Divide both side by 2

Na = 2/2

Na = +1

Thus, the oxidation number of sodium (Na) in Na₂O₂ is +1

Hexane is an alkane with six carbon atoms.

Hexane is an organic substance having the chemical formula C6H14. It is a straight-chain alkane containing six carbon atoms. When pure, it is an odorless, colourless liquid with a boiling point of roughly 69 °C (156 °F). It is a broadly applicable non-polar solvent that is quite safe, mainly unreactive, affordable, and easily evaporable.

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Answer:

197.07 K

Explanation:

To solve this problem we can use the PV=nRT equation, where:

We input the data:

And solve for T:

Answer:

Before we can sketch the Lewis structures of molecules, we must first understand the octet rule. The octet rule asserts that when atoms combine to create compounds, electrons are gained, lost, or shared among them, resulting in a stable electron configuration defined by eight valence electrons as a result. These rules are used in conjunction with the main-group components of the second period.

Explanation:

Hope it helps:)

A combustion reaction is a type of chemical reaction that involves the rapid combination of fuel (typically a hydrocarbon) with oxygen, resulting in the release of energy in the form of heat and light.

Combustion reactions are often characterized by the presence of a flame and the production of carbon dioxide (CO₂) and water (H₂O) as products.

In the given balanced combustion reaction:

C₂H₂ + 5O₂ → 4H₂O + 2CO₂

The stoichiometric ratio indicates that 1 mole of C₂H₂ reacts with 2 moles of CO₂ produced. Therefore, if 4.44 moles of C₂H₂ react, we can calculate the moles of CO₂ produced using the ratio:

Moles of CO₂ = (4.44 mol C₂H₂) × (2 mol CO₂ / 1 mol C₂H₂)

Moles of CO₂ = 8.88 mol

Therefore, 8.88 moles of CO₂ will be produced in the combustion reaction.

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Answer:

-3.19x10³ J

Explanation:

Since the surroundings absorbed 3.19 × 10³ J (or 3190 J) of heat, the system, or the dissolution reaction, must have lost the same amount of heat. The heat for the system, then, is -3.19 × 10³ J (or -3190 J). We know this is true because of the first law of thermodynamics, "heat is a form of energy, and thermodynamic processes are therefore subject to the principle of conservation of energy".

According to law of conservation of energy, if 31.5 J of heat is gained than same amount of heat is lost .

According to law of conservation of energy, it is evident that energy is neither created nor destroyed rather it is restored at the end of a chemical reaction .

Law of conservation of mass and energy are related as mass and energy are directly proportional which is indicated by the equation E=mc².Concept of conservation of mass is widely used in field of chemistry, fluid dynamics.

Law needs to be modified in accordance with laws of quantum mechanics under the principle of mass and energy equivalence.This law was proposed by Julius Robert Mayer in the year 1812.

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Answer:

Scoopula

Explanation:

For transfer of small solids to a piece of glassware, we will use Scoopula because it is a scoop utensil in the form of a spatula used mainly used in chemistry laboratory to transfer solids: to a weigh paper for the solids to be weighed; to a cover slip for measurement of the solids melting point; to a graduated cylinder; to a watch glass from a flask or even beaker through scraping.

Answer:

0.084 moles of H₂O

Explanation:

RAM of Mg = 24, of H = 1, of O = 16

Mg(OH)₂ + 2HCI --> MgCl2 + 2H₂O

Mole of Mg(OH)₂ = mass/MolarMass

= 1/24 = 0.042mol

From the equation,

1 mole of Mg(OH)₂ = 2 moles of H₂O

0.042mol of Mg(OH)₂ = 2 × 0.042 of H₂O

= 0.084 moles of H₂O

Answer:

chemical reactions

Explanation:

the synthetic substance is resulted from preparation of substance at laboratory

Answer:

chemical reactions

Explanation:

Some types of solids that are insoluble in water are:

Many solids are insoluble in water, meaning they do not dissolve in water to a significant extent. Here are some examples of common solids that are generally insoluble in water:

Metals: Most metals, such as gold, silver, platinum, and copper, are insoluble in water.

Non-Metallic Elements: Many non-metallic elements, such as carbon (in the form of graphite or diamond), sulfur, phosphorus, and iodine, are insoluble in water.

Metal Oxides: Some metal oxides, particularly those of less reactive metals, are insoluble in water. Examples include aluminum oxide (Al2O3), iron(III) oxide (Fe2O3), and lead(II) oxide (PbO).

Metal Carbonates: Most metal carbonates are insoluble in water. Examples include calcium carbonate (CaCO3), lead(II) carbonate (PbCO3), and copper(II) carbonate (CuCO3).

Metal Sulfides: Many metal sulfides are insoluble in water. Examples include lead(II) sulfide (PbS), silver sulfide (Ag2S), and mercury(II) sulfide (HgS).

Insoluble Salts: Certain salts have limited solubility in water. Examples include silver chloride (AgCl), lead(II) iodide (PbI2), and calcium sulfate (CaSO4).

It's important to note that while these solids are generally insoluble in water, they may exhibit some solubility to a small extent. The solubility of a solid in water can vary depending on factors such as temperature, pressure, and the presence of other solutes.

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9moles of N2

Given the reaction represented by the equation:

Given the following parameters

• Moles of ammonia = 18 moles

According to stoichiometry, 1 mole of nitrogen produces 2 moles of ammonia. Therefore the moles of nitrogen required is given as:

Hence the moles of nitrogen required to produce 18 mol of ammonia is 9moles

Answer:

SUPER MARIOLWEJHRTÑWQEGTPWIQETGQWKÑEJGBKSDLJBGKSJDLGB

Explanation: