No, not all pewter contains lead. Lead-free pewter is available and is made with a combination of tin, antimony, and copper.
What is Pewter?
Pewter is an alloy made primarily of tin, with small amounts of copper, antimony, and sometimes bismuth. It is a malleable metal with a silvery-grey color, and is commonly used to make decorative items and functional items such as plates, teapots, and figurines.
Lead-free pewter is a type of alloy metal made up of tin, antimony, and copper. This type of pewter does not contain any lead, making it a safe and non-toxic alternative to traditional pewter. Lead-free pewter is often used in the production of jewelry, ornaments, kitchenware, and even tableware. It is valued for its malleability, resistance to corrosion, and durability. Lead-free pewter is also more cost-effective than traditional pewter and is ideal for creating intricate designs and details.
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NH3 H3Ot NHA SO,2 CHCI3 Crude Sketch H H 2- H-N- H / H -O - H H- N - H CH H Calculations (# of valence electrons, # of bonds, etc. 5 + ( 1 X 3 ) 13 + 6 - 1 5+(1x4)-1 316) +2 + 6 = 8 = 8 = 26 = 8 Lewis Structure H +1 = H- O- H | H- N -H H : O' O: # electron groups, electron group geometry # of bonded atoms, molecular shape Resonance structures (if any) Polar or nonpolar
The compound NH₃ is tetrahedral in geometry and is non-polar. SO₂ is polar in nature and has a bend shape. CHCl₃ is tetrahedral and it is polar.
What are polar compounds?
Polar compounds are those having a permanent dipole moment. When the atoms bonded together have significant difference in electronegativity the electrons will attracts more to the highly electronegative atom and there occurs a net dipole moment results in polarity.
The ammonium ion NH₄⁺ is a tetrahedral molecule having no polarity. The dipole moments cancel each other due its tetrahedral nature. SO₂ is bend in geometry due to the presence of lone pair of electrons on oxygen atom. It is a polar compound.
The compound trichloromethane has a net dipole moment and it is polar with a tetrahedral structure.
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What is the mass in grams of 1.00 mol?
The value of the mole is equal to the number of atoms in exactly 12 grams of pure carbon-12. 12.00 g C-12 = 1 mol C-12 atoms = [tex]6.02*10^{23}[/tex] atoms.
The mole is a common unit of measurement in chemistry for the amounts of reactants and products in chemical processes. Previously, "mole of molecules" and "mole of atoms" were denoted by the terms gram-molecule and gram-atom, respectively. The quantity of dissolved material per unit volume of solution is known as a solution's molar concentration, and the unit generally used to describe this quantity is moles per litre(mol/L).
The ratio of a sample's mass to the substance's total mass is known as the molar mass of a material. The number of moles in the sample serves as a measure of the substance's quantity.
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Complete the mechanism for the reaction of pent-2-one with methoxide. In all three boxes add lone pair electrons and nonzero formal charges for the given species. In the first two boxes draw the curved arrow notation to illustrate how this reaction occurs.
The mechanism for the reaction of pent-2-one with methoxide. In all three boxes add lone pair electrons and nonzero formal charges for the given species is attached below in image.
What is methoxide ?Methoxides are organic salts having a CH3O anion in organic chemistry. These alkoxides are the most basic. Although other metal-cation compounds including lithium, rubidium, and caesium methoxide exist, sodium and potassium methoxide are the most commonly used.
In order to create a poly ether with a high molecular weight, it is utilized as an initiator of an anionic addition polymerization with ethylene oxide. Both sodium methoxide and its potassium-prepared equivalent are routinely employed as catalysts in the synthesis of biodiesel on a large scale.
Thus, The mechanism for the reaction of pent-2-one with methoxide. In all three boxes add lone pair electrons and nonzero formal charges for the given species is attached below in image.
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How is Mg different from MgO?
The primary distinction between magnesium as well as magnesium oxide is also that magnesium is indeed a chemical element and magnesium oxide is an ionic compound.
Although magnesium as well as magnesium oxide are related, they are not the same. Magnesium is indeed a base element, and magnesium oxide is indeed a magnesium derivative. This latter is also a magnesium compound and salt.
Magnesium is a chemical element with the atomic number (12) as well as symbol Mg. It is classified as just a metal as an element and has all of the features of metallic elements. It is strong and malleable, and it can't be broken down because it is already made up of atoms. Magnesium oxide, in contrast hand, is a compound formed when magnesium reacts with oxygen. It has a unique chemical formula (MgO) that results from an ionic bond. This bond, however, could be broken by chemical decomposition.
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What are the products of the following reactions? (A trace amount of acid is present in each case.)
A. cyclopentanone + ethylamine
B. cyclopentanone + diethylamine
C. acetophenone + hexylamine
D. acetophenone + cyclohexylamine
Carbonyl compounds are organic compounds that contain a carbonyl group (C=O). These include the ketones and aldehydes. Ketones are those that have two alkyl groups attached to the carbonyl carbon while aldehydes are those that contain an alkyl group and a hydrogen atom. These compounds can undergo addition reactions with primary and secondary amines which results in the formation of imines and enamines.
The products of the given reactions are shown in the completed equations given attachment.
Reactions A, C and D results in the formation of an imine since ethylamine, hexylamine and cyclohexylamine are all primary amines. Reaction B, on the other hand, produces an enamine since diethylamine is a secondary amine.
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What is the 2 4 hour rule?
You can safely keep freshly potentially dangerous foods, such as cooked meat and foods that contain meat, milk products, prepared vegetables and fruits cooked pasta and rice and cooked as well as processed foods containing eggs, at temperature changes in the danger zone, or between 5° C and 60° C, for up to 2 hours or 4 hours. This information is provided by the 2 Hour/ 4 Hour Rule.
Why should food businesses consider the 2-hour / 4-hour rule for food hygiene?Strong food safety precautions have been implemented as a result of reduction strategies that have been used to reduce the frequency of salmonella-related foodborne illnesses. These tactics are centered on the Food Standards Code, which also incorporates the alternative temperature control technique known as the "2-hour / 4-hour rule."
What are the 4 parts of the food standards Code?Flavor enhancers, food safety, labeling, and foods that require prior approval, such as genetically modified foods, are all covered by the Food Standards Code.
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Why is a molecule of co2 nonpolar even though the bonds between the carbon atom and the oxygen atoms are polar?.
A molecule of CO2 is a nonpolar molecule, even though the bonds between the carbon atom and the oxygen atoms are polar. This is due to the fact that the two polar bonds in the molecule cancel each other out.
The oxygen atoms in CO2 have a partial negative charge due to their higher electronegativity, while the carbon atom has a partial positive charge. These two polar bonds create a dipole moment in the molecule, but the two dipoles point in opposite directions and thus cancel each other out.
The fact that the two polar bonds cancel out each other is known as “molecular geometry”. This describes how the atoms of a molecule are arranged in space. In the case of CO2, the molecule has a linear arrangement of atoms, meaning that the two oxygen atoms are arranged on opposite sides of the carbon atom. This arrangement creates a symmetrical molecule, where the two dipoles of the polar bonds are facing each other and canceling each other out.
In addition to the cancellation of the dipole moments, the nonpolarity of CO2 is also due to its low polarity. The polarity of a molecule is determined by the difference in electronegativity between the atoms that make up the molecule. In the case of CO2, the difference between the electronegativities of the carbon and oxygen atoms is relatively low, meaning that the resulting molecule is nonpolar.
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Which is about the effect of the angle of insolation on the amount of heat a material absorbs?
The angle of insolation has the effect that the more the angle of insolation, the more the amount of heat absorbed by a material.
The impact of the insolation angle on the heat absorption rate of a substance can be explained by the following factors that affect how much sunlight is absorbed on Earth's surface:
The soil will be warmer because it will catch more direct light if somehow the angle of insolation is higher.The sun's rays' insolation angle is the angle at which the rays strike a specific spot on Earth.The elevation of the sun in the sky in reference to the observer is referred to as the angle of insolation. Angles of insolation start at 0 degrees.The Earth orbits the sun in an elliptical route rather than a perfect circle, thus some seasons of the year see Earth closer to the sun than others.The angle of insolation of the earth's axis: The earth's axis is inclined by 66 [tex]\frac{1}{2}[/tex] degrees with respect to its orbital plane.Read more about the Angle of insolation from:
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Answer: B and E
Explanation: I just did it
Two pieces of the same metal are placed on a table. The pieces of metal have the same density, mass, and texture. Which characteristic must be the only difference between the two samples?.
The characteristic must be the only difference between the two samples is B-they have different dimensions.
A metallic is a material that, whilst freshly prepared, polished, or fractured, suggests a lustrous appearance, and conducts energy and warmth exceptionally well. It become explicitly said withinside the query that the each samples are precisely portions of the equal metallic. If this is so, portions of the equal metallic should have the equal density, comprise the equal amount of depend, have the equal boiling factor and feature the equal quantity of depend in keeping with unit volume.
Thus, the correct option is B.
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Complete question:
Two pieces of the same metal or placed on the table with the piece of metal have the same density mass and texture which characteristic must be the only difference between the two samples
A-they contain a different amount of matter per unit volume
B-they have different dimensions
C-they are made up of a different type of matter
D-they have different boiling points
How do you calculate RMS?
RMS or Root Mean Square value can be calculated by taking the square root of arithmetic mean of squared observations.
It's formula for n values is given by
Xrms = √(x1²+x2²+..... Xn²) /N
What is RMS?RMS is root mean Square can be defined as square root of the mean square. It is the arithmetic mean of the squares of group of values. It can also be called as a quadratic mean and even called as varying function.
So basically by three main steps we can calculate Root mean square
1) To get squares of all the values
2) By calculating average of obtained squares
3) Taking the square root of the average
Thus, RMS or Root Mean Square value can be calculated by taking the square root of arithmetic mean of squared observations.
It's formula for n values is given by
Xrms = √(x1²+x2²+..... Xn²) /N
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what did the photoelectric experiment demonstrate?
The photoelectrons' kinetic energy increased with an increase in light frequency, and the current increased with a rise in light amplitude.
What is demonstrated by the photoelectric effect?
The current increased with a rise in light amplitude, and the kinetic energy of the photoelectrons increased with a rise in light frequency.
What does the photoelectric effect prove?
Light can be categorised as a wave because it demonstrates all three of the essential features of a wave—interference, diffraction, and polarisation.
The photoelectric effect, however, only makes sense if we consider light to be made up of tiny energy packets (particles) known as photons; in other words, the photoelectric effect proves that light is a particle.
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strontium 38sr90 has a half-life of 29.1 yr. it is chemically similar to calcium, enters the body through the food chain, and collects in the bones. consequently, 38sr90 is a particularly serious health hazard. how long (in years) will it take for 99.9778% of the 38sr90 released in a nuclear reactor accident to disappear?
The amount of 38Sr90 produced from a nuclear reactor accident that will take half lifetime to dissipate is 99.9778%.
How is the half-life time determined?The half-life of a reaction is the length of time required for the reactant concentration to decrease to half its initial value. A first-order reaction's half-life is a constant that is correlated with its rate constant: t1/2 = 0.693/k.
Why is the term "half-life" used?A radioactive element's half-life is the amount of time it takes for it to decay to half of its original value. It can be concluded from this that a source's activity has a half-life if it takes some time before it drops to half its starting value.
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How do you graph a parabola function?
To draw a parabola graph, we have to first find the vertex for the given equation.
This can be done by using x=-b/2a and y = f(-b/2a). Plotting the graph, when the quadratic equation is given in the form of f(x) = a(x-h)^2 + k, where (h, k) is the vertex of the parabola, is its vertex form.
parabola
A parabola is a plane curve which is mirror-symmetrical and is approximately U-shaped. It fits several superficially different mathematical descriptions, which can all be proved to define exactly the same curves.
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carbonate buffers are important in regulating the ph of blood at 7.40. if the carbonic acid concentration in a sample of blood is 0.0013 m, determine the bicarbonate ion concentration required to buffer the ph of blood at ph
The blood buffer has a pH of 7.4, whereas the blood sample has a carbonic acid content of 0.0013 M.
The chemical compound of hydrogen, carbon, and oxygen is known as carbonic acid (H2CO3).It is produced in minute quantities when water dissolves its anhydride, carbon dioxide (CO2). Two covalent double bonds bind the core carbon atom of carbon dioxide, also referred to as carbonic acid gas, to the two oxygen atoms.
Calculation:Calculating the concentration is as follows:pH = pKₐ + log HCO⁻₃/ H₂CO₃
7.4 = - log(4.3 × 10⁻₇)+ log HCO⁻₃/ 0.0013m
log HCO⁻₃/ 0.0013m = 7.4 - 6.37
log HCO⁻₃/ 0.0013m = 1.03
log HCO⁻₃/ 0.0013m = 10¹°⁰³
HCO⁻₃ = 1.3 ₓ 10⁻².
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The diagrams above show the ultraviolet absorption spectra for two compounds. Diagram 1 is the absorption spectrum of pure acetone, a solvent used when preparing solutions for an experiment. Diagram 2 is the absorption spectrum of the solute for which the absorbance needs to be measured to determine its concentration. When the student reads the absorbance of the solution at 280 nm, the result is too high. Which of the following is most likely responsible for the error in the measured absorbance?
answer choices
The student added too little solute to the acetone before measuring its absorbance.
The student rinsed the cuvette with the solution before filling the cuvette with the solution.
The student forgot to calibrate the spectrophotometer first by using a cuvette containing only acetone.
The wavelength setting was accidentally changed from 280 nm
to 300 nm before the student made the measurement.
The most likely mistake responsible for the error in the measured absorbance is that The student added too little solute to the acetone before measuring its absorbance.
Spectrophotometry is a branch of electromagnetic spectroscopy that deals with quantifying a material's reflection or transmission properties as a function of wavelength. Absorbance (A), also known as optical density, is the quantity of light absorbed by a solution (OD). Transmittance is the quantity of light that passes through a solution.
A spectrophotometer is a device that monitors the number of photons (light intensity) absorbed when a sample solution passes through it. The spectrophotometer may also be used to measure the quantity of a known chemical substance (concentrations) by measuring the intensity of light observed. Absorbance is the quantity of light of a specific wavelength that a given substance prevents from passing through it.
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a student has 0.24 ml of 0.125 m solution of barium hydroxide, ba(oh)2. her assignment is to titrate the solution to the equivalence point with exactly 6 ml of hydrochloric acid. what molarity should the acid solution be?
The molarity of a solution is the number of moles of the solute in one liter of the solution. That is, the molarity of 0.1 N oxalic acid is 0.05 M.
What is the acidic solution's concentration?Acidic solutions are those that include H3O+ ions in concentrations greater than 1 x 10-7 M.Basic substances are those with the H3O+ ion concentration is less to 1 x 10-7 M.
How is a 37% Hypotonic solution made?100 ml od solution to 37 ml of solute.To make a 0.1N HCL solution, add 8.3 ml or 37% HCL in 1 liter with D5W or NS.12 moles/L or 12 x 36.5 equals 438 g/L or 438 mg/ml in the formula 12M (37% HCL).
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Identify subatomic particles Question The prefix in subatomic tells us that subatomic particles are: Select the correct answer below:
O particles made of atoms
O the basic building blocks of atoms 2
O particles of similar size to atoms
O particles that power nuclear submarines FE Type here to search
Sub is going to be the prefix. The basic building blocks of atoms will be the right response.
It will be smaller than the bigger object in terms of composition. They will thus be smaller than an atom. Atoms are larger than subatomic particles. They are going to be the atom's building blocks. So the fundamental constituents of atoms will be the right response in this case. Protons, neutrons, and electrons—the particles that we know make up atoms—are also referred to as subatomic, of course. Thus, we refer to them as subatomic particles. They are the subatomic particles that go towards the creation of an atom. Okay, so that would be the proper response. that second response choice.
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When 100 g of sugar is dissolved in 100 mL of water there is no increase in volume what characteristic of matter is illustrated by this observation?
As the volume is expanded, it implies that the liquid's liquid particles have characteristics of having vast intermolecular gaps (water). Liquid water has open spaces between its particles, which are not securely connected.
For what purposes is dissolved?Traditionally, pictures that connect two scenes together are transitioned between using the dissolve editing technique. A dissolve is a progressive change from one image to the next as opposed to a direct cut from one shot to the next.
In what is water dissolved?Water allows substances to dissolve, including salt, sugar, and coffee. These things dissolve. Warm or hot water typically helps them dissolve more quickly and more effectively. Sand and pepper are soluble in hot water, but not at room temperature.
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How would the system change if the container were placed on a hot plate? some kinetic energy would be produced. Some kinetic energy would be destroyed. The kinetic energy of the molecules would increase. The kinetic energy of the molecules would decrease.
If a container is placed on a hot plate, the kinetic energy of molecules inside the container will increase.
It is a fundamental theory of thermodynamics that energy cannot be produced and neither be destroyed. So obviously from the fundamental theorem of thermodynamics, the first two options in the given question ( some kinetic energy would be produced and some kinetic energy would be destroyed ) are obviously wrong.
Since the container is placed on a hot plate, the heat energy will get transferred from the plate to the container, and hence the molecules inside the container will get heated and excited. Therefore the kinetic energy of molecules inside the container will increase.
So basically, in this case, the heat energy of the plate is converted to the kinetic energy of molecules inside the container.
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caffeine lewis structure
Answer:
Explanation:
Caffeine has a structure similar to purine. It is made of eight carbon, ten hydrogen, four nitrogen, and two oxygen atoms. Its chemical formula is C8H10N4O2.
draw lewis symbols for the most stable ion formed by: sodium, oxygen, calcium, and chlorine.
The Lewis structure of the most stable form of sodium, oxygen, calcium and chlorine.
Diagrams that show the chemical bonds between the atoms of a molecule are known as Lewis dot structures, also known as electron dot structures. Additionally, they show the total number of lone pairs found in each of the atoms that make up the molecule. Lewis structures, also known as electron dot structures or Lewis structures, are quite prevalent. According to Lewis, an acid is an electron pair acceptor and a base is an electron pair giver. One dot is included in a Lewis Electron Dot Formula along with the symbol of the element and each valence electron. The steps to explain the electron dot formula are listed below. Note down a skeletal structure using only the element symbols that shows a realistic bonding pattern.
Hence, Lewis structure depict possibilities of bonding.
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What is the chemical reaction between cornstarch and water?
Cornstarch and water comes under suspension mixture in which a solid solute dispersed into a liquid solvent .
When we press the mixture quickly, the starch molecules comes close together. Due to this the water to get trapped between chains of starch and create a semi-rigid structure.
There in reality is no chemical reaction which occurs between them as the cornstarch still remains cornstarch at the end of the reaction.
Just a very light bond is formed between them which can be broken easily.
The viscosity of the fluid is increased leading to addition of some other interesting properties to the substance.
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What are 3 ways you can determine if a compound is ionic or covalent?
We can determine whether a compound is ionic or covalent by comparing their bonds. If a compound will contain ionic bonds then they are ionic in nature whereas if it contains covalent bond they are covalent in nature.
The compounds formed of ionic bonds are made up of metals so they are metallic in nature as ionic compounds contain a metal bonded to a nonmetal.
They form crystals and typically have high melting and boiling point and are hard and brittle, and form electrolytes in water.
Whereas in case of covalent compounds they are made up of nonmetals bonded to one another. Covalent compounds have lower melting and boiling points as compared to ionic compounds they are softer in comparison and are electrical insulators.
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1) List the following sets of quantum numbers in order increasing energy:
I . n=4, / = 1, m/=1, ms = +1/2
II. n=3, /=2, m/= -1, ms = +1/2
III. n=4, / =0, m/ = 0, ms = +1/2
The increasing energy order of the quantum numbers is III < II < I.
What are quantum numbers?There are a total of four quantum numbers in atoms: primary quantum number (n)orbital angular momentum quantum number (l), magnetic quantum number (ml), electron spin quantum number (ms). However, other possibilities include angular momentum, spin, etc. Quantum numbers frequently specifically characterize the energy levels of electrons in atoms. Flavour quantum numbers, which are internal quantum numbers that determine a particle's kind and how it interacts with other particles using basic forces, are a significant family of quantum numbers. It is challenging to compile a list of all conceivable quantum numbers because any quantum system can have one or more quantum numbers.Here, the increasing energy order of the sets of quantum numbers is III < II < I.To learn more about quantum numbers, refer:
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Is chocolate being melted a physical or chemical change?
A solid material physically changing into a liquid is called melting. When brought to room temperature, chocolate can simply solidify because it doesn't undergo any chemical changes.
When chocolate melts, what changes?The average distances between the molecules of the chocolate increase as it melts because they spread out more. This is the reason why, after melting, they appear as liquids. Melting is typically thought of as merely a physical transformation. This is so that the chocolate's chemical composition is unaltered.
Is chocolate that is melting a physical thing?The transformation of a solid state into a liquid state is referred to as melting. The species involved or their chemical makeup remain unchanged during melting. Melting is therefore a physical characteristic.
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Which sets of structures are homologous?
Homologous structures are those that don't exactly appear alike or serve the same purpose but are structurally similar, indicating that they have a common ancestor. Examples of such structures are a bird's wing and a whale's flipper.
What homologous structures are there?The arms of primates and bats are two common examples of homologous structures in evolutionary biology. Genetically, these two structures are related even though they do not share the same function or appearance as their most recent common ancestor.
What are three homologous structural examples?Examples of homologous structures include the human arm, a bird or bat's wing, a dog's leg, a dolphin or whale's flipper, and a bird or a bat's wing. They are distinctive and possess despite having differing goals, they are comparable and possess similar qualities.
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how is a new element formed in a star
Nuclear fusion
Explanation:
What is the first step of enzyme action?
A substrate enters the energetic site of the enzyme. This bureaucracy the enzyme-substrate complicated.
The response then occurs, changing the substrate into merchandise and forming an enzyme merchandise complicated. The merchandise then go away the energetic site of the enzyme. The first step of an enzyme catalyzed response is catalytic turnover the binding of substrate via way of means of the enzyme the discharge of product dissociation of the ES complicated ES -> E + P. An enzyme-catalyzed response may be more or less divided into 3 stages: enzyme-substrate binding, "catalysis" and product release.
Thus, the first step of enzyme action is the binding of enzyme and substrate.
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Boron consists of two naturally occurring isotopes, 10B which has a mass of 10.012 a.m.u and 11B which has a mass of 11.009 a.m.u. The atomic weight of boron is 10.81 a.m.u. Calculate the percentage composition of each isotope.
The percentage composition of each isotope, given their various masses is:
Percentage of 10B is 20%Percentage of 11B is 80%How do I determine the percentage composition of each isotope?The percentage composition of each isotope can be obtained as follow:
Mass of 1st isotope (10B) = 10.012 amuMass of 2nd isotope (11B) = 11.009 amuAverage atomic mass of boron = 10.81 amuPercentage of 1st = A =?Percentage of 2nd (2nd%) = 100 - A =?Average atomic mass = [(Mass of 1st × 1st%) / 100] + [(Mass of 2nd × 2nd%) / 100]
10.81 = [(10.012 × A) / 100] + [(11.009 × (100 - A) / 100]
10.81 = 0.10012A + 11.009 - 0.11009A
Collect like terms
10.81 - 11.009 = 0.10012A - 0.11009A
-0.199 = -0.00997A
Divide both sides by -0.00997
A = -0.199 / -0.00997
A = 20%
Thus,
B = 100 - A
B = 100 - 20
B = 80%
From the above calculations, we can conclude that the percentage composition of each isotope is:
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Which solute will lower the freezing point of 1 kg of water to 3.72 C?
The solute that will lower the freezing point of 1 kg of water to 3.72 C is sodium chloride (NaCl).
A solute is any substance that is dissolved in a liquid to form a solution. It can be either a solid, a liquid, or a gas. Solutes are typically dissolved in a liquid to form a homogenous mixture, and the liquid itself is called the solvent. Examples of solutes include sugar, salt, and other minerals in water, as well as oxygen, nitrogen, and carbon dioxide in air. As solutes are dissolved, the concentration of the solute in the solvent increases, resulting in a decrease in the amount of solvent present.
When a substance such as NaCl is dissolved in water, the freezing point of the water is lowered. This is due to the fact that the solute molecules interfere with the hydrogen bonding of the water molecules, which makes it harder for them to form a crystalline structure as the temperature decreases, thus reducing the freezing point.
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