2. What is the concentration in mol dm-3 of a solution which contains 3 moles of a given solute in 0.25dm³ (250cm³) of solution.​

The statement "Substances which have a very low solubility in water are likely to have a positive/negative ∆Hsol" is generally true, with some exceptions. ΔHsol refers to the enthalpy change associated with the dissolution of a substance in water. If the value of ΔHsol is negative, then the process of dissolving the substance in water releases energy (i.e., it is exothermic), and the substance is said to be soluble in water. Conversely, if ΔHsol is positive, then the process of dissolving the substance in water requires energy (i.e., it is endothermic), and the substance is said to be insoluble or only slightly soluble in water.

Substances that have a very low solubility in water are typically hydrophobic (water-repelling), and their intermolecular forces of attraction are stronger than their forces of attraction to water molecules. Therefore, it requires a significant amount of energy to break these intermolecular forces and allow the substance to dissolve in water, resulting in a positive ΔHsol. However, there are some exceptions, such as some salts, which have a high lattice energy and are highly soluble in water despite having a positive ΔHsol.

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Silicon is not an element of set 18. The correct answer to this question is b.

An element is a substance that cannot be broken down into simpler substances through chemical reactions. Each element is identified by a unique atomic number, which represents the number of protons in its nucleus. The set of 18 elements includes helium, neon, and krypton, but not silicon.

Any one of the seven chemical elements that compose Group 18 (VIIIa) of the periodic table is referred to as a noble gas. Helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson are the constituent elements (Og).

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The net ionic equation that provides a concise representation of the chemical change occurring when the aqueous solutions of potassium phosphate and magnesium nitrate are combined is, PO4³⁻(aq) + 3Mg²⁺(aq) → Mg3(PO4)2(s)

When aqueous solutions of potassium phosphate (K3PO4) and magnesium nitrate (Mg(NO3)2) are combined, a double displacement reaction occurs.

This results in the formation of solid magnesium phosphate (Mg3(PO4)2) and a solution of potassium nitrate (KNO3).

To write the net ionic equation for this reaction, we need to consider the species that undergo a change in their chemical state.

In this case, the solid magnesium phosphate is insoluble in water and forms a precipitate.

The potassium nitrate, being a soluble compound, dissociates into its constituent ions in solution.

The complete ionic equation for the reaction can be written as follows:

3K⁺(aq) + PO4³⁻(aq) + 3Mg²⁺(aq) + 6NO3⁻(aq) → Mg3(PO4)2(s) + 6K⁺(aq) + 6NO3⁻(aq)

To simplify the equation and highlight the species involved in the chemical change, we can write the net ionic equation by removing the spectator ions (ions that do not participate in the reaction):

PO4³⁻(aq) + 3Mg²⁺(aq) → Mg3(PO4)2(s)

This net ionic equation focuses on the essential components of the reaction, showing that phosphate ions (PO4³⁻) from the potassium phosphate solution react with magnesium ions (Mg²⁺) from the magnesium nitrate solution to form solid magnesium phosphate.

Overall, the net ionic equation provides a concise representation of the chemical change occurring when the aqueous solutions of potassium phosphate and magnesium nitrate are combined, emphasizing the formation of solid magnesium phosphate and the absence of spectator ions.

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The reaction's increased heat generates a greater enthalpy.

The reaction CaCl2(s)---> CaCl2(aq) has an enthalpy of formation of -252.5 kJ.

Enthalpy, or the amount of heat required to change a substance's state, rises in this reaction as it moves from a solid to a liquid state, increasing the amount of disorder.

The disorder and entropy will both increase if the reaction generates more heat and transitions to a liquid state, increasing the enthalpy in the process.

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Egg whites are simply made frothy by adding air during the whipping process. It's a physical shift as they are still eggs whites—a material that has not changed. Yet in a chemical transformation.

To put it another way, a chemical always consists of the same "substance." There are some substances in nature, like water. Other chemicals, including chlorine, are produced

All of these things are made of chemicals, some organic and others manmade, including air, water, iron, fuel, clothes, stones, equipment, plastics, plants, and food. Chemicals can be made up of several distinct chemicals or they might be specific chemical molecule like water. Nitrogen, carbon, water, carbon dioxide, and other substances are all present in air.

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Answer: 2 and 4

Explanation:

Detergent, ethanol, and salt can all play important roles in extraction processes, depending on the specific type of biomolecule being extracted and the purification needs.

Detergent, ethanol, and salt can all play important roles in different types of extraction processes. Here's an overview of how each of them can be used:

Detergent: Detergents are often used to extract proteins or other biomolecules from biological samples. Detergents are able to solubilize membrane-bound proteins by disrupting the lipid bilayer of the cell membrane. This allows the proteins to be extracted into a solution. Detergents can also help to break apart protein complexes, making it easier to isolate individual proteins.

Ethanol: Ethanol is commonly used as a solvent in extractions because it can dissolve a wide range of organic compounds, including lipids and proteins. Ethanol can also be used to precipitate DNA or RNA from a solution. When added to a solution of DNA or RNA, ethanol causes the nucleic acids to clump together and form a visible precipitate, which can then be collected and further purified.

Salt: Salt is often used in DNA and RNA extractions to help remove proteins and other impurities from the sample. When salt is added to a solution, it can cause proteins to denature and precipitate out of the solution. The salt can then be removed along with the precipitated proteins. In addition, salt can help to bind DNA or RNA to a solid support, such as a column or a membrane, making it easier to isolate the nucleic acid from other components of the sample.

In summary, detergent, ethanol, and salt can all play important roles in extraction processes, depending on the specific type of biomolecule being extracted and the purification needs. Detergents are useful for solubilizing proteins, ethanol can dissolve a wide range of organic compounds, and salt can help to remove impurities and bind DNA or RNA to a solid support.

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Solubility, odor, and color are physical properties; they can all be discerned without having to subject a substance to a chemical change. Flammability, on the other hand, is a chemical property. Thus, choices A, B, and C would be correct examples of physical properties.

The synthesis of nylon requires solutions of 5% hexamethylenediamine and 5% adipoyl chloride. This polymer will form between layers of the solutions. To remove the nylon, one can choose to dissolve it in the 5% hexamethylenediamine or in the 5% adipoyl chloride.

Nylon, a synthetic polymer, is produced from the combination of adipoyl chloride and hexamethylenediamine. This process is called the synthesis of nylon. Nylon is a highly flexible material that is resistant to wear and tear, as well as chemical and heat degradation. The synthesis of nylon requires solutions of 5% hexamethylenediamine and 5% adipoyl chloride, respectively, for the two reactants to be mixed together.

The reaction between these two chemicals is exothermic, which means that it releases heat. The heat generated in the reaction drives the reaction forward, resulting in the formation of nylon. The chemical formula for nylon is (-CO-NH-)n, where n is a large number that reflects the degree of polymerization. To remove the nylon, it is soaked in an acid solution. The acid dissolves the nylon, separating it into its constituent components, which can then be purified and reused.

The most commonly used acid for this process is hydrochloric acid. The process of removing nylon from its solvent is called the "acid-catalyzed hydrolysis of nylon." Nylon is used in a variety of applications, including textiles, packaging materials, and electrical components, among others. Its properties make it ideal for use in applications that require durability, strength, and flexibility. Nylon's physical properties, including its resistance to heat and chemical degradation, make it ideal for use in applications such as electrical insulation, packaging materials, and textiles.

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Mass percent is given by:

We will firstly use the desnity to calculate the mass of the solution:

Now that we have the mass of the solution we are able to calculate the mass percent:

Answer: Mass percent is 10.6%

Answer:

Question One:

A kitchen recipe and a chemical equation are similar in that both involve the combination of specific ingredients in a specific manner to produce a desired outcome. However, there are some key differences between the two.

In a kitchen recipe, the ingredients are usually listed in a descriptive, qualitative manner, often with rough measurements (e.g. "one cup of sugar"). The recipe may also include instructions for preparation, such as cooking or mixing, that are not included in a chemical equation.

A chemical equation, on the other hand, represents a chemical reaction using quantitative, symbolic representations of the reactants and products. The reactants are listed on the left-hand side of the equation and the products on the right-hand side. The coefficients in a chemical equation indicate the number of molecules or moles of each substance participating in the reaction.

Overall, a kitchen recipe and a chemical equation both serve as guides for a process that involves the combination of ingredients, but the nature of the information and the type of outcome being described are different.

Question Two:

Balancing an equation could not directly apply to a kitchen recipe. A kitchen recipe does not have the same level of precision or quantitative detail as a chemical equation. Additionally, a kitchen recipe is more focused on taste and appearance, whereas a chemical equation must be balanced in terms of mass and charge to accurately represent the reaction. While the principles of measuring and combining ingredients in a recipe may be similar to balancing an equation, the end goals and criteria for success are quite different.

Explanation:

1. Both a kitchen recipe and a chemical equation provide a sequential set of instructions that guide the process to achieve a specific result, but while a recipe guides the preparation of food with descriptive language, a chemical equation represents a chemical reaction using chemical symbols and formulas.

2. Balancing an equation does not apply to a kitchen recipe because recipes focus on taste and presentation, allowing flexibility and adaptation.

1. A kitchen recipe and a chemical equation share some similarities but also have distinct differences. Both involve a set of instructions or steps to produce a desired outcome, but they serve different purposes and use different language and symbols.

Similarities:

a) Both a kitchen recipe and a chemical equation provide a sequential set of instructions that guide the process to achieve a specific result.

b) Ingredients/Reactants: In both cases, there is a list of ingredients (in a recipe) or reactants (in a chemical equation) that are combined to produce the final product.

Differences:

a) Purpose: The primary purpose of a kitchen recipe is to guide the preparation of food, focusing on taste, texture, and presentation. On the other hand, a chemical equation's purpose is to represent a chemical reaction, focusing on the transformation of reactants into products and the conservation of mass and charge.

b) Language and Symbols: Kitchen recipes typically use descriptive language, measurements (cups, teaspoons, etc.), and cooking times, whereas chemical equations use chemical symbols and formulas to represent elements and compounds, along with coefficients to balance the equation.

2. Balancing an equation, as it is done in chemical reactions, is not applicable to kitchen recipes. The concept of balancing an equation is specific to chemical reactions and is based on the fundamental laws of conservation of mass and charge.

In kitchen recipes do not involve chemical reactions, and there are no strict conservation laws to follow. The focus of a recipe is to create a dish with a specific taste, texture, and presentation, rather than ensuring the conservation of mass or other chemical properties.

Recipes are designed to be flexible, allowing adjustments based on personal preferences, dietary restrictions, and ingredient availability. Balancing a kitchen recipe, as in a chemical equation, would not have any meaningful significance or practical application in the culinary context. Instead, recipes are intended to be adaptable and creative, leaving room for individual tastes and culinary experimentation.

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The ion that is incorrectly named is C) Cs+ cesium(l) ion.

Caesium is a chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-golden alkali metal with a melting point of 28.5 °C (83.3 °F), which makes it one of only five elemental metals that are liquid at or near room temperature. Caesium has physical and chemical properties similar to those of rubidium and potassium.

Caesium(1+) is a caesium ion, a monovalent inorganic cation, a monoatomic monocation and an alkali metal cation.

The correct name for Cs+ is cesium ion, without specifying the oxidation state as "l". The oxidation state of an ion is not typically indicated in the name of the ion. Cesium is a Group 1 element and forms a monovalent cation with a charge of +1. Therefore, Cs+ is simply referred to as the cesium ion.

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The formula when converting g/mL to mg/L is to multiply the mass / volume value by 1e+6

When we do this we come up with 1,730,000

This however, should be written as either 1.73⋅10^5 or 1.73E+5.

Answer:

false

Explanation:

The particles are held together too strongly to allow movement from place to place but the particles do vibrate about their position in the structure. With an increase in temperature, the particles gain kinetic energy and vibrate faster and more strongly

Answer

-52.2 Joules

Explanation

Given that;

Mass of krypton, m = 12.3 g

Temperature change, ΔT = 22.2°C - 39.3°C = -17.1°C

The specific heat of gaseous krypton, c = 0.248 J/g°C.

What to find:

The energy change, Q.

Step-by-step solution:

The energy change, Q can be determined using:

Q = mcΔT

Putting the values of the given parameters into the formula, this yields:

Therefore the energy change = -52.2 Joules

Answer:

2.5e-5

Explanation:

The oxidation number of nitrogen in the nitrate ion (NO₃⁻) is +5. To determine the oxidation number, we assign a hypothetical charge to each element in the compound based on its electronegativity and known rules.

In NO₃⁻, oxygen is assigned an oxidation number of -2, since it typically exhibits a -2 charge in most compounds. Since there are three oxygen atoms in NO₃⁻, the total charge from the oxygen atoms is -6.

The overall charge of the nitrate ion is -1, so the sum of the oxidation numbers of all the atoms in the ion must equal -1. Therefore, to balance out the charge, nitrogen must have an oxidation number of +5.

We can calculate this by using the equation:

(+5) + (-6) = -1

Hence, the correct answer is b. +5.

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Answer:

dissolve

Explanation:

When it dissolves , no chemicals are formed and it is considered as a physical property.

Answer:

what is it ???? I need help to

Answer:

Dermal tissue of the stems and leaves is covered by a waxy cuticle that prevents evaporative water loss. Stomata are specialized pores that allow gas exchange through holes in the cuticle. Unlike the stem and leaves, the root epidermis is not covered by a waxy cuticle which would prevent absorption of water.

Explanation:

Answer:Gas is the answer

The approximate amount of water used in the reaction is 1000 g. Student B is correct.

From the equation of the reaction, the mole ratio of the H2 produced and the H2O separated is 1:1.

mole of H2 produced = mass/molar mass

                                        = 112/2

                                           = 56 moles

This means that 56 moles of H2O was also separated.

Mass of 56 moles of H2O = 56 x 18

                                           = 1,008 g

Also from the equation of the reaction, the mole ratio of O2 produced to water separated is 1:2.

Mole of O2 produced = 888/32

                                       = 27.75 moles

Equivalent mole of H2O = 27.75 x 2

                                        = 55.5 moles

Mass of 55.5 moles of H2O = 55.5 x 18

                                               = 999 g

Thus, the approximate amount of water used in the reaction must have been 1000 g. Student B is correct.

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c. No, it is not enthalpy favored since the chemical system gains energy.

If the temperature of the water lowers while ammonium nitrate dissolves in it, the process is endothermic and heat is absorbed by the system.

Through the process of dissociation into its individual ions, ammonium nitrate readily dissolves in water. Because it was created from a strong acid (HF) and a weak base (NH3), this salt has an acidic character (HNO3). This reaction is extremely exothermic and it happens quickly.

A spontaneous reaction favors one that favors the creation of products in the environment in which it is taking place. A campfire that is roaring is an exothermic example of a spontaneous reaction. 

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The substance that is an electrolyte is: potassium

In chemistry an electrolyte is known as a substance or compound that has the capacity of being an electrical conductor when it is dissolved into a solution with water. Some examples of electrolytes are: potassium, common salt (NaCl), calcium.

In chemistry a solution is known as a homogeneous mixture of two or more components called:

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Red is the color reaction of vitamin E with n-butyl alcohol since it is an acid-base reaction where vitamin e acts as an acid and n-butyl alcohol is a base.

Tocopherols are a class of fat-soluble substances that make up vitamin E. It can dissolve in fats and oils if it is fat-soluble. Alcohol's toxic effects can be lessened by vitamin E, which is also an effective possible treatment for liver oxidative damage brought on by alcohol. A white liquid with a vinous smell is n-BuOH. It has a scent that is somewhat reminiscent of fuse1 oil. When vitamin E scavenges peroxyl radicals, it creates vitamin E radical, which can then be reduced by vitamin C or other reducing substances to regenerate vitamin E or further oxidised into -tocopheryl quinone. A biomarker of vitamin E's antioxidant activity is -tocopheryl quinone.

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Answer:

the answer is B Astroid Belt

Answer:

CH4

Explanation:

A= CH4

Answer:

It vaporizes.

Explanation:

When a substance absorbs heat energy and doesn't increase its temperature, that means it's going through a change of phase.

The next change of phase for a liquid is turning to a gas, so it vaporizes.

The new volume is 2*n*R*T1/8.40, where n and T1 are known values.

What is volume?
Volume is a measurement of three-dimensional space that is occupied. Numerous imperial or US customary units, as well as SI-derived units (like the cubic metre and litre), are frequently used to quantify it numerically (such as the gallon, quart, cubic inch). Volume and length (cubed) have a symbiotic relationship. The volume of a container is typically thought of as its capacity, not as the amount of space it takes up. In other words, the volume is the amount of fluid (liquid or gas) that the container could hold.

The ideal gas law equation is PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the absolute temperature.
We are given P1 = 8.40 atm, V1 = ?, T1 = ?, and we want to find V2. We know that P2 = P1/2, and T2 = 2*T1.
We can rearrange the ideal gas law equation to solve for V2.
V2 = (n*R*(2*T1))/(P1/2)
V2 = (n*R*(2*T1))/(8.40/2)
V2 = 2*n*R*T1/8.40
Therefore, the new volume is 2*n*R*T1/8.40, where n and T1 are known values.

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Answer: 67.23 L

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number \(6.023\times 10^{23}\) of particles.

To calculate the number of moles, we use the equation:

\(\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}\)

Putting in the values we get:

\(\text{Number of moles of methane}=\frac{48g}{16g/mol}=3moles\)

1 mole of methane occupies = 22.4 L

Thus 3 moles of methane occupy = \(\frac{22.4}{1}\times 3=67.23L\)

Thus volume of 48 grams of methane gas is 67.23 L

Answer:

your should probably be warming the acid

Explanation:

because when you are it is disappearing

Answer:

Warming the acid

Explanation:

This is because when the acid is heated, the particle of the acid gain more energy (kinetic to be more precise) causing more collisions to occur, colliding even more with the particles of the magnesium ribbon. This increases the rate of disappearance of the magnesium ribbon.