Xe and Pb are atomic elements. I₂ and Br₂ are molecular elements. CaCl₂ and Al₂S₃ are ionic compounds and NO₂ and H₂S are molecular compounds.
Atomic elements are the elements which cannot be broken down further and combine together to form molecules. Among the substances given to us, Xenon (Xe) and Lead (Pb) can be categorised as atomic elements. Molecular elements are formed when the same elements combine with each other. I₂ and Br₂ are molecular elements.
Ionic compounds are consist of ions bound together. CaCl₂ and Al₂S₃ are ionic compounds. Molecular compounds are formed up of two or more elements and NO₂ and H₂S are molecular compounds.
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What is the similarities of polar covalent bonds and nonpolar covalent bonds?
Answer:
Explanation:
Polar covalent bonds and nonpolar covalent bonds are similar in that they both involve the sharing of electrons between atoms in a covalent bond. In both types of bonds, the atoms involved share electrons in order to achieve a full valence electron shell, which gives the bond its stability.
Both polar and nonpolar covalent bonds have a covalent character, meaning they are formed by the sharing of electrons between atoms, as opposed to the transfer of electrons which is seen in ionic bonds. Also, both type of bonds are strong chemical bonds, which means they have a high bond energy, meaning they require a lot of energy to break.
Determine the number of neutrons, protons, and electrons for a bromide ion that has a mass number of 77, and a charge of −1.
Answer: For the bromide ion with a mass number of 79 and a charge of -1, there are 36 electrons, 35 protons, and 44 neutrons present for the element that has a mass
For the element that has a mass number of 56 and 30 neutrons
Explanation:
A 0.95 m aqueous solution of an ionic compound with the formula MX has a freezing point of −3.0 °C. Calculate the van’t Hoff factor (i) for MX at this concentration.
The van't Hoff factor for MX in its aqueous solution at the given concentration is 1.7.
How to calculate the factorThe solution given is an aqueous solution of an ionic compound whose formula is MX. If MX is dissolved in water, it will dissociate almost completely into [tex]M^{+}[/tex] and [tex]X^{-}[/tex] ions. The particles of solute in the solution are [tex]M^{+}[/tex], [tex]X^{-}[/tex] and trace quantities of any unassociated MX. As a result, there are more solute particles in total concentration in the solution following MX's dissociation than there were in the solution prior to MX's dissociation.A colligative feature, depression in freezing point depends on the quantity of solute particles but is unaffected by the type of particles.
The van't Hoff factor is integrated into the formula for colligative qualities like depression in freezing point in order to account for the effective number of solute particles after association or dissociation of molecules of a substance in its solution.The relation between depression in freezing point (Δ[tex]T_{f}[/tex]) and concentration of the compound before dissociation or association in the solution:
Δ[tex]T_{f}[/tex] = [tex]i[/tex] × [tex]K_{f}[/tex] × [tex]m[/tex]Where [tex]i[/tex] is van't Hoff factor, [tex]K_{f}[/tex] is molal depression constant and [tex]m[/tex] is molality of the compound present in the solution.Freezing point of pure water [tex]T^{0} _{f}[/tex] = 273 KFreezing point of given solution [tex]T_{f}[/tex] = [tex]3.0^{0} C[/tex] = 273 K - 3 = 273 KDepression in freezing point Δ[tex]T_{f}[/tex] = [tex]T_{f} ^{0}[/tex] - [tex]T_{f}[/tex] = 273 K - 270 K = 3therefore Δ[tex]T_{f}[/tex] = 3 KConcentration of MX in the solution is [tex]m = 0.95 M[/tex]Molal depression constant for the solvent (water) is [tex]K_{f} =1.86 K/m[/tex] (m is the molal concentration)We have, Δ[tex]T_{f} = i[/tex] ×[tex]K_{f}[/tex] x [tex]m[/tex]Van't Hoff factor [tex]i=[/tex] Δ[tex]T_{f}[/tex]/[tex]K_{f}[/tex] x [tex]m[/tex][tex]i= \frac{3 K}{1.8K/m X 0.95m}[/tex][tex]i=[/tex] 1.7
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Explain why the formula shown below is incorrect for the compound potassium chloride:
Formula: KCL
The formula KCL is not the correct formula for the compound potassium chloride. Potassium chloride is a compound made up of potassium and chlorine ions, and its chemical formula is KCl.
Write a balanced chemical equation to represent the following chemical reaction.
potassium iodide + lead(II) nitrate âLead(II) iodide + potassium nitrate
Answer:
KI + Pb(NO3)2 -> PbI2 + KNO3
Explanation:
The balanced chemical equation for the reaction of potassium iodide with lead(II) nitrate to form lead(II) iodide and potassium nitrate is:
KI + Pb(NO3)2 -> PbI2 + KNO3
In this equation, the coefficients in front of the compounds indicate the number of moles of each substance that are needed to balance the equation. This means that there are equal numbers of atoms of each element on both sides of the equation.
Step 1:?(slow)Step 2:NO3(g)+CO(g)→NO2(g)+CO2(g (fast)Overall:NO2(g)+CO(g)→NO(g)+CO2(g)A two-step reaction mechanism is proposed for a gas-phase reaction, as represented above. Which of the following correctly identifies both the chemical equation for step 1 and the rate law for the overall reaction?
The step that determines rate is the one that moves most slowly in a series of non-elementary reactions.
Reaction of CO(g) with NO2(g)
CO(g) + NO2(g) ? NO(g) + CO2(g)
At low temperatures, the experimentally determined rate law expression is:
Rate = k [NO2]2
A two step reaction mechanism is suggested
Step 1 SLOW NO2(g) + NO2(g) ? NO3(g) + NO(g)
Step 2 FAST CO(g) + NO3(g) ? CO2(g) + NO2(g)
CO(g) + NO2(g) ? NO(g) + CO2(g)
The step that determines rate is the one that moves most slowly in a series of non-elementary reactions. The rate-determining step is the initial reaction since it happens slowly. We can get the rate law from this.
Additionally, because the specie is not present in the overall reaction equation, it can only be an intermediate that was created in step 1 and depleted in step 2.
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What is the percentage composition of each element in dinitrogen monoxide, N2O?
Percentage composition of nitrogen and oxygen are 63.6% and 36.3% respectively. This word refers to the overall mass percentage of each element contained in a compound.
What is percentage composition?The ratio of each element's quantity to the sum of all the individual components present in the compound, multiplied by 100, is what determines any compound's percentage composition.
Any compound's percent composition expresses its makeup in terms of all the components that are present. The chemical analysis reveals the relevance of this composition calculation. The concentration of such an element in a mixture or component in a combination is expressed using the idea of mass percentage composition.
percentage composition of nitrogen= (28/44)×100=63.6%
percentage composition of oxygen=(16/44)×100=36.3%
Therefore, percentage composition of nitrogen and oxygen are 63.6% and 36.3% respectively.
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for each pair of elements, first write the ions that they form. then predict the ionic compound formed when combined.
The ionic compound that occurs between each pair of elements has the following formula:
[tex]Al_2} S_{3}[/tex]AIN [tex]k_{2} o[/tex]MgO [tex]BaF_{2}[/tex][tex]Be_{3} N_{2}[/tex]The formula of the ionic compound of each pair is:
(a)Aluminum and Sulfur:
Aluminum sulfide, commonly known as [tex]Al_{2} S_3}[/tex], is created when aluminum and sulfur are combined. Its molar mass is 150.158 g/mol. Al has an oxidation state of +3, while the sulfur in [tex]Al_{2} S_{3}[/tex]is in a -2 oxidation state.
[tex]Al_2} S_{3}[/tex] = [tex]Al^{+3}[/tex] + [tex]S^{-2}[/tex]
(b) Aluminum and Nitrogen:
Solid aluminum nitride is known as aluminum nitride (AlN). It's an electrical insulator with a high thermal conductivity of up to 321 W/. (mK).
AlN = [tex]Al^{+3}[/tex] + [tex]N^{+3}[/tex]
(c) Potassium and oxygen
When potassium and oxygen combine, a substance known as potassium oxide is created. The chemical name for it is [tex]K_{2} O[/tex]. Due to its high level of reactivity, potassium is never found in its free form. It is straightforward for it to react with oxygen atoms to produce [tex]K_{2} O[/tex]because of its +1 valency.
( K₂ )⁺¹ + O²⁻ → K₂O
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The complete question follows
Write a formula for the ionic compound that forms between each pair of elements.
Acetylene gas (C2H2) used in welding, produces an extremely hot flame when it burns
in pure oxygen according to the reaction
2 C₂H₂(g) +5 O₂(g) → 4CO₂(g) + 2 H₂O(g).
How much H₂O is produced when 40000 g of
C₂H₂ burns completely?
Answer in units of g.
The mass of H₂O produced when 40000 g of C₂H₂ burns completely is 27692.3 g.
What is the mass of water produced when 40000 g of C₂H₂ burns completely in the air?The mass of water produced when 40000 g of C₂H₂ burns completely in the air is determined from the mole ratio as given in the equation of the reaction as follows;
Equation of reaction: 2 C₂H₂(g) + 5 O₂(g) → 4 CO₂(g) + 2 H₂O(g)
The molar mass of C₂H₂ = 26 g
The molar mass of water = 18 g
The mole ratio of C₂H₂ to H₂O is 1 : 1
The mass of water produced = 40000/26 * 18 g
The mass of water produced = 27692.3 g
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Calculate the value of Dell H Kj upon kg for the following reaction using the list thermochemical reaction equation 2N2 + O2 form 2n2o DELLH equals to?second equation to end to 2NH3 + 3 N 2 O forM 4N2 + 3h2o DELL H equals to -1010KJ third equation for 4NH3 + 3 O2 form 2 N2 + 6h2oh DELL H equals to -1531 kj
The enthalpy for the reaction, N[tex]_2[/tex](g) + 1/2 O[tex]_2[/tex](g) →N[tex]_2[/tex]O(g) is +81.5. among all the given options, the correct option is option A.
What is enthalpy?The amount of heat inside a system is measured as enthalpy. This heat is used to cause a process to occur. Enthalpy is indeed a thermodynamic quantity since every system that involves heat is referred to be a thermodynamic system.
Additionally, it is important to remember that each system has a number of players. These individuals each have their own pressure and volume. We already know that the ratio of a system's pressure to its volume is constant.
N[tex]_2[/tex](g) + 1/2 O[tex]_2[/tex](g) →N[tex]_2[/tex]O(g)
i)2 NH[tex]_3[/tex](g) + 3 N[tex]_2[/tex]O(g) → 4N[tex]_2[/tex](g) + 3 H[tex]_2[/tex]O(l) ∆H°/kJ= -1010 KJ
ii)4 NH[tex]_3[/tex](g) + 3 O[tex]_2[/tex](g) → 2 N[tex]_2[/tex](g) + 6 H[tex]_2[/tex]O(l) ∆H°/kJ = -1531 KJ
Multiply second equation with 4 and first equation with 2. Now substract third equation from fourth equation.
N[tex]_2[/tex](g) + 1/2 O[tex]_2[/tex](g) →N[tex]_2[/tex]O(g) ΔH=+81.5
Therefore, the enthalpy for the reaction, N[tex]_2[/tex](g) + 1/2 O[tex]_2[/tex](g) →N[tex]_2[/tex]O(g) is +81.5.
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your computer should be password-protected. your best protection against losing your data is to back up your files to your hard drive. firewalls inspect data transmitted between a computer and external recipients to prevent unsolicited data exchanges. with cloud storage, you can retrieve your data anytime from anywhere in the world. a thief must physically steal your computer to gain access to its files and data. there is no way to track your smartphone once it is lost.
Your best protection against losing your data is to back up your files to your hard drive. Firewalls inspect data transmitted between a computer and external recipients to prevent unsolicited data exchanges
What is password-protection?
Password protection is an access control technique that helps keep important data safe from hackers by ensuring it can only be accessed with the right credentials. Password protection is one of the most common data security tools available to users—but they are easily bypassed if not created with hackers in mind.Password protection is a security process that protects your computer from unauthorized access via authentication and verification processing. In simple words, your online information is protected using a unique password – only an authorized user with the correct password can view the content.Passwords provide the first line of defense against unauthorized access to your computer and personal information. The stronger your password, the more protected your computer will be from hackers and malicious software. You should maintain strong passwords for all accounts on your computer.To learn more about data refers to:
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Please help on 1.15!! A, b, and/or c!
The answers to the following calculations with the proper number of significant figures and with the correct units are: (a) 8.00 kg, (b) 22.6 g, (c) 3.45 cm³
What is significant figures?
Significant figures are a way to express the accuracy of a measurement. They are the digits that are known accurately plus one last uncertain digit. This last uncertain digit is estimated based on the precision of the measuring instrument. Significant figures are used to communicate the precision of a measurement to other scientists. The number of significant figures in a measurement is dependent on the measuring instrument used.
The answer should have two significant figures, since the least precise measurement, 12.90 kg, has two significant figures. The answer should have three significant figures, since the least precise measurement, 0.64 g, has three significant figures. The answer should have three significant figures, since the least precise measurement, 0.859 cm³, has three significant figures.
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Name TWO things chemical and nuclear reactions have IN COMMON/SHARE.
Answer:
Both chemical and nuclear reactions involve changes in the arrangement of atoms or subatomic particles.
Both chemical and nuclear reactions result in the release or absorption of energy.
Chemical and nuclear reactions are both types of reactions that involve a change in the composition of matter. Here are two things that they have in common/share:
1. Conservation of mass: Both chemical and nuclear reactions follow the law of conservation of mass. This means that the total mass of the reactants is equal to the total mass of the products. In other words, mass cannot be created or destroyed during a chemical or nuclear reaction.
2. Energy changes: Both chemical and nuclear reactions involve a release or absorption of energy. Chemical reactions typically involve the breaking and forming of chemical bonds, which releases or absorbs energy. Nuclear reactions involve the splitting or combining of atomic nuclei, which releases or absorbs much larger amounts of energy. In both cases, the energy change can be measured and analyzed.
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help with rate order of reaction pls
The rate of reaction depends on only one of the species.
What is order of reaction?The order of a reaction is a measure of the dependence of the reaction rate on the concentration of reactants.
A reaction of zero order has a rate that is independent of the concentration of reactants, while a reaction of first order has a rate that is directly proportional to the concentration of one reactant, and so on. The overall order of a reaction is the sum of the orders of the reactants in the rate equation.
In this case, we can see that the rate of reaction depends on only one reactant.
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what molecule is most consistent with the following? what molecule is most consistent with the following? i ii iii iv v
The molecule in question is C12H22O2. This can be determined by using the information provided about the number of carbon, hydrogen, and oxygen atoms present in the molecule.
The chemical formula for the molecule is determined by listing the elements present in the molecule and their respective number of atoms.
The chemical formula for this molecule is C12H22O2. Using this information, it is possible to determine that the molecule is composed of 12 carbon atoms, 22 hydrogen atoms, and 2 oxygen atoms. The molecule with this chemical formula is known as "dodecanoic acid" and it is a straight-chain carboxylic acid.
It is also known as Lauric acid, which is found in many natural fats and oils and is a common ingredient in soaps and cosmetics. It is a white, waxy solid with a faint, characteristic odor. It is used in the manufacture of a wide variety of products, such as soaps, lubricants, and surfactants.
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What is the chemical formula and structure of the molecule that is composed of 12 carbon atoms, 22 hydrogen atoms, and 2 oxygen atoms?
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metal x replaces the ions of metal y from solution, but it cannot replace the ions of metal z from solution. the order these metals should have in the activity series (from top to bottom) is
The order these metals should have in the activity series (from top to bottom) is z,x,y.
An activity series is a list of elements in order of decreasing reactivity. Elements at the top of the activity series are more reactive than those at the bottom. Since metal x can replace the ions of metal y from solution but not those of metal z, it means that metal x is more reactive than metal y but less reactive than metal z. Therefore, the order of these metals in the activity series would be z (most reactive), y (least reactive), x (more reactive).
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Which of the following processes start with a material that is in a fluid or semi fluid state and solidifiesthe material in a cavity: (a) casting, (b) forging, (c) machining, (d) molding,(e) pressing, and, (f) turning?
The processes of (a) casting, (d) molding, and (e) pressing all begin with a fluid or semi-fluid material and solidify it in a hollow.
What is casting?The term "casting" describes the process of creating a solid item by pouring a liquid into a mould and letting it set.
This technique is frequently used in metallurgy to create metal components, but it can also be applied to other industries like ceramics and polymers. The material used to create the mould is often one that can endure both high temperatures and the pressure of the liquid being poured into it. To speed up the solidification process, the liquid is frequently heated to a high temperature.
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What functional group is found in an aldehyde?
O A. Carbonyl
OB. Hydroxyl
O C. Ester
O D. Amino
Answer:
The answer is A. Carbonyl.
Carbonyl functional group is found in an aldehyde. Therefore, option (A) is correct.
What are the functions of carbonyl groups?A functional group with the formula C=O that is composed of a carbon atom double-bonded to an oxygen atom and is divalent at the C atom is known as a carbonyl group in organic chemistry.
The function of the carbonyl group is to break up the bonds in the carbon chain. The electronegative oxygen molecule will in general draw in additional electrons than the carbon it is attached to inside the carbonyl gathering.
There are many aromatic carbonyl compounds. Substances which incorporate carbonyls incorporate the compound answerable for the smell of vanilla and cinnamon.
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surface chemists design metal alloys for specific functions in everyday life. which of the following does not demonstrate a benefit of using an alloy? A. Goldd is mixed with copper or silver to make a less expensive form that can be used in jelwery. B. Smalleer atoms of one metal are incorporated into the structure of larger metal atoms to reduce malleability andimprove strength of the structure. C. Densities of metals are closely matched to increase desirable properties without increased cost. D. The canductivity has been eliminated due to the stronger bonding of the different types od metals.
The statement that does not demonstrate a benefit of using an alloy is the conductivity has been eliminated due to the stronger bonding of the different types of metals. The answer is D.
Alloys are mixtures of two or more metals that are designed to have specific properties for a particular application. A common example of alloy used in jewelry is where gold is mixed with copper or silver to create a less expensive material with the same appearance as pure gold.
Another example for the use of alloy is where smaller atoms of one metal are incorporated into the structure of larger metal atoms to reduce malleability and improve strength of the structure. Another benefit of alloy is that the densities of metals are closely matched to increase desirable properties without increased cost. In most of the alloys, the conductivity is retained or even increased due to the combined properties of the different types of metals.
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Your question seems to be missing, but I suppose the question was:
"surface chemists design metal alloys for specific functions in everyday life. which of the following does not demonstrate a benefit of using an alloy?
A. Gold is mixed with copper or silver to make a less expensive form that can be used in jewelry.
B. Smaller atoms of one metal are incorporated into the structure of larger metal atoms to reduce malleability and improve strength of the structure.
C. Densities of metals are closely matched to increase desirable properties without increased cost.
D. The conductivity has been eliminated due to the stronger bonding of the different types of metals."
An experiment at Sandia National Labs in New Mexico is performed at 758.7 mm Hg. What is this pressure in atm?
40 points
Answer:
0.9997 atm.
Explanation:
To convert pressure from millimeters of mercury (mm Hg) to atmospheres (atm), you can use the conversion factor 1 atm = 760 mm Hg.
To convert 758.7 mm Hg to atm, you can divide the pressure in mm Hg by 760:
758.7 mm Hg / 760 mm Hg/atm = 0.9997 atm
So the pressure in atm is approximately 0.9997 atm.
According to the unit conversion of pressure, the pressure in atmospheres is 0.998 atmospheres.
What is pressure?Pressure is defined as the force applied on an object perpendicular to it's surface per unit area over which it is distributed.Gauge pressure is a pressure which is related with the ambient pressure.
There are various units by which pressure is expressed most of which are derived units which are obtained from unit of force divided by unit of area . The SI unit of pressure is pascal .
It is a scalar quantity which is related to the vector area element with a normal force acting on it.It is distributed over solid boundaries and across arbitary sections of fluid normal to the boundaries at every point.
As 1 atmosphere= 760 mm Hg , thus, 758.7 ×1/760=0.998 atmospheres.
Thus, the pressure in atmospheres is 0.998 atmospheres.
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acetyl-coa brings carbon atoms to the citric acid cycle. these carbon atoms are passed through many intermediary steps. for example, there are
Acetyl-CoA brings carbon atoms to the citric acid cycle. These carbon atoms are passed through many intermediary steps. For example, there are 4 carbon atoms (C) present in oxaloacetate.
About Acetyl-coaA molecule important in metabolism and is useful in many biochemical reactions is called Acetyl-coa . The main function of this molecule is to provide as many carbon atoms which are in the acetyl group to the citric acid cycle to be oxidized to obtain energy, and synthesize a neurotransmitter named acetylcholine which is obtained by a chemical reaction with the help of the enzyme choline acetyltransferase and a by-product in the form of coenzyme A.
Generally, the metabolism of fatty acids will produce acetyl-CoA for the citric acid cycle. In the liver, when the circulation of fatty acids is too high, the production of acetyl CoA from reduction of fat will exceed the energy needed by the cells of the body and will form a ketone group. The high ratio of ketone groups in the blood circulation can cause ketosis or ketoacidosis.
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Exercise 1. Calculate the volume of a sample of ammonia (NH3) at 0°C and 1.00 atm if the sample occupies a volume of 0.25 L at 27°C and 0.850 atm.
The volume of a sample of ammonia at 0°C and 1.00 atm is approximately 0.232 L.
How to find the volume of a sample of ammonia (NH3)?
The relationship between the volume and temperature of a gas is described by Charles's law, which states that the volume of a gas is proportional to its temperature, provided that the pressure and number of moles of the gas remain constant.
Mathematically, this can be expressed as:
V1 / T1 = V2 / T2
Where V1 and T1 are the initial volume and temperature, and V2 and T2 are the final volume and temperature.
Given:
Initial volume = 0.25 L
Initial temperature = 27°C = 27 + 273.15 = 300 K
Initial pressure = 0.850 atm
Final temperature = 0°C = 273.15 K
Final pressure = 1.00 atm
To convert from one pressure to another, we can use the ideal gas law:
P1V1 = P2V2
Where P1 and V1 are the initial pressure and volume, and P2 and V2 are the final pressure and volume.
Rearranging, we can find the final volume:
V2 = P1V1 / P2
V2 = (0.850 atm) * (0.25 L) / (1.00 atm)
V2 = 0.213 L
Finally, using Charles's law, we can find the volume of the sample at 0°C and 1.00 atm:
V2 / T2 = V1 / T1
V2 / 273.15 = V1 / 300
V1 = (V2 * 300) / 273.15
V1 = (0.213 L) * (300 K) / (273.15 K)
V1 = 0.232 L
So, the volume of a sample of ammonia at 0°C and 1.00 atm is approximately 0.232 L.
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ammonium dihydrogen phosphate, formed from the reaction of phosphoric acid with ammonia, is used as a crop fertilizer as well as a component of some fire extinguishers. what are the mass percentages of nitrogen and phosphorus in the compound? round each of your answers to significant figures.
The mass percentage of the nitrogen is 24.34 % and the mass percentage of phosphorus is 26.95 %.
The formula for the ammonium dihydrogen phosphorus is NH₆PO₄.
The molar mass of ammonium dihydrogen phosphate = 115 g/mol
The molar mass of nitrogen = 28 g/mol
The molar mass of phosphorus = 31 g/mol
The mass percentage of nitrogen = (1 × 28 / 115 ) × 100 %
= 24.34 %
The mass percentage of phosphorus = ( 1 × 31 / 115 ) × 100 %
= 26.95 %
Thus, the mas percentage of nitrogen is 24.34 % and phosphorus is 26.95 %.
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What volume of a 25% (W/V) solution of HNO3
The volume of a 25% solution of HNO3 that is needed to contain 12.6g of HNO3 is: 50.4 ml .
How to find the volume of a 25% solution of HNO3?Based on the information given the 25%(w/v) implies that 25 g of HNO3 contains in 100 ml of the solution.
Now let find the volume of a 25%(w/v) solution of HNO3 that is needed to contain 12.6 g HNO3
Volume needed = 12,6×100/25
Volume needed = 50.4 ml of solution required
Therefore we can conclude the volume needed is 50.4ml .
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The complete question is:
What volume of a 25% solution of HNO3 is needed to contain 12.6g of HNO3?
19. Radioactive copper-64 decays with a half-life of 12.8 days.
a. What is the value of k in s-¹?
b. A sample co rains 28.0 mg 64-Cu. How many decay events will be produced in the first second? Assume the atomic mass of 64-Cu is 64.0 u.
c. A chemist obtains a fresh sample of 64-Cu and measure radioactivity. She then determines that to do an experiment, the radioactivity cannot fall below 25% of the initial measured value. How long does she have to perform the experiment?
The chemist has 14.4 days to perform the experiment.
What is the value of k in s-¹?The value of k in s-¹ is 0.0530.The number of decay events in the first second is 5.5 x 1012.The value of k in s-¹ is equal to the natural logarithm of two (ln2) divided by the half-life (T1/2) of 12.8 days. Therefore, k = ln2/12.8 days = 0.04968 s⁻¹.The number of decay events produced in the first second can be calculated using the equation N = N0e^(-kt), where N0 is the initial number of atoms of the radioactive isotope, k is the decay constant, and t is the time interval in seconds.Since the atomic mass of 64-Cu is 64.0 u and the mass of the sample is 28.0 mg, the number of atoms in the sample can be calculated by dividing the mass of the sample by the atomic mass of the isotope, which gives us N0 = 28.0 mg/64.0 u = 0.4375 x 10^24 atoms.Substituting this value for N0 and the value for k (0.04968 s⁻¹), we get N = 0.4375 x 10^24 e^(-0.04968s⁻¹) = 0.4375 x 10^24 e^(-0.04968) = 4.355 x 10^23. Therefore, the number of decay events produced in the first second is 4.355 x 10^23.The chemist has to perform the experiment before the radioactivity of the sample falls below 25% of the initial measured value. This can be calculated by rearranging the equation N = N0e^(-kt) to get t = (ln(N/N0))/k.Substituting the initial number of atoms (N0) and the decay constant (k) and solving for t, we get t = (ln(0.25N0))/0.04968 = (ln(0.25 x 0.4375 x 10^24))/0.04968 = 15.6 days. Therefore, the chemist has 15.6 days to perform the experiment.To learn more about half-life experiment refer to:
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using figures 5.21, 5.22, and the text, describe the structure and function of g-protein coupled receptors and ligand-gated ion channels.
TheThe function of GPCRs is highly diverse, recognizing a wide range of ligands, including photons, small molecules, and proteins. Ion channels are pores in the cellular membrane that allow ions to pass in and out of the celThe function of GPCRs is highly diverse, recognizing a wide range of ligands, including photons, small molecules, and proteins. Ion channels are pores in the cellular membrane that allow ions to pass in and out of the cell.
The function of GPCRs is highly diverse, recognizing a wide range of ligands, including photons, small molecules, and proteins. Ion channels are pores in the cellular membrane that allow ions to pass in and out of the cell.GPCRs contain seven transmembrane helices (gray), three extracellular loops (ECLs) and an amino terminus (orange), and three intracellular loops (ICLs) and a carboxyl terminus (purple).The transmembrane domain consists of the transmembrane helices, as well as the extracellular and intracellular loops.Ligand-gated ion channels (LGICs) are integral membrane proteins that contain a pore which allows the regulated flow of selected ions across the plasma membrane. Ion flux is passive and driven by the electrochemical gradient for the permeant ions.To know more about Proteins:-
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Please help on 1.15!!
The equation, in its most basic form, asserts that energy and mass (matter) are interchangeable; they are various manifestations of the same thing. Both energy and mass can become one another under the correct circumstances.
The universe contains how much matter and energy?Dark energy, which makes up the remaining 68.5 percent of the universe, is a mystery factor that appears to be speeding up the universe's expansion.The equation, in its most basic form, asserts that energy and mass (matter) are interchangeable; they are various manifestations of the same thing. Both energy and mass can become one another under the correct circumstances.Dark energy, which makes up the remaining 68.5 percent of the universe, is a mystery factor that appears to be speeding up the universe's expansion.The equation, in its most basic form, asserts that energy and mass (matter) are interchangeable; they are various manifestations of the same thing. Both energy and mass can become one another under the correct circumstances.The complete question is,
"Mass times light speed squared equals energy."
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C3H8 + 5O2 --> 3CO2 + 4H2O
Assume if we combust 1.3L of propane(C3H8). How much CO2 will be produced?
4.5 L
3.9 L
2.7 L
22.4 L
The amount of carbondioxide that will be produced if 1.3L is combusted is 3.9L (option B).
How to calculate volume using stoichiometry?Stoichiometry refers to the study and calculation of quantitative (measurable) relationships of the reactants and products in chemical reactions (chemical equations).
According to this question, propane gets combusted in air to produce carbondioxide and water as follows:
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
Based on the above equation, 1 mole of propane produces 3 moles of carbondioxide.
This suggests that 1.3L of propane will produce 3.9L of carbondioxide.
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Does the phrase “you are what you eat” make scientific sense according to your knowledge of enzymes and transport?
The phrase “you are what you eat” does not make scientific sense according to the knowledge of enzymes and transport because foods are broken down by enzymes into small subunits which are common to all biomolecules.
What is the role of enzymes in the digestive system?The role of enzymes in the digestive system is based on breaking down food into smaller components during metabolic activities.
Therefore, with this data, we can see that the role of enzymes in the digestive system is to degrade biomolecules that are ingested into common subunits.
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based on the pie chart, which of the following approaches would likely yield the biggest benefits for reducing nitrogen inputs into the chesapeake bay?
Based on the pie chart, Local governments work with farmers to implement strategies to minimize nitrogen runoff from farm fields would likely yield the biggest benefits for reducing nitrogen inputs into the chesapeake bay.
In order to control the transport of nitrogen from source regions to surface waters, managing agriculture and other human activities on the landscape usually entails reducing nitrogen applications and/or making changes to improve the efficiency of natural elimination of nitrogen. The transfer of nitrogen in particle form from the land surface to surface waters may be restricted by management techniques intended to reduce runoff and soil losses, such as riparian buffers, contour tillage, or manure or fertiliser injection.
The efficiency of management strategies for lowering nitrogen transfer from the land surface to surface waters is constrained by a number of factors and mechanisms. In anoxic riparian areas, nitrate may be converted to nitrogen gas, although it frequently moves past riparian areas to reach locations where streams discharge . Nitrogen losses may be significant where a thin surficial aquifer restricts groundwater to shallow flow paths, but minimal where a thicker surficial aquifer permits deeper groundwater flow. Variable hydrogeologic conditions on the Eastern Shore contribute to variable nutrient retention in riparian buffers.
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Based on the pie chart, which of the following approaches would likely yield the biggest benefits for reducing nitrogen inputs into the Chesapeake Bay?