The change in enthalpy for the reaction of 4.00 g of CH4(g) burning in excess oxygen according to the reaction: CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g); H°rxn = –802.2 kj is 200.6 kJ.
Calculate the number of moles of CH4(g) using the molar mass of CH4(g):
4.00 g CH4(g) / 16.04 g/mol = 0.2494 mol CH4(g)
Use the balanced chemical equation to determine the ratio of moles of CH4(g) to the change in enthalpy:
1 mol CH4(g) : -802.2 kJ
Use the ratio to calculate the change in enthalpy for the given amount of CH4(g):
0.2494 mol CH4(g) x (-802.2 kJ / 1 mol CH4(g)) = -200.6 kJ
Therefore, the change in enthalpy for the reaction of 4.00 g of CH4(g) burning in excess oxygen is -200.6 kJ.
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Does extracellular fluid include interstitial fluid?
Yes, interstitial fluid is included in the extracellular fluid.
Extracellular fluid refers to all the fluid that is outside of cells and includes both interstitial fluid and plasma. Interstitial fluid is the fluid that surrounds individual cells and fills the spaces between tissues. Plasma, on the other hand, is the fluid component of the blood that carries nutrients, hormones, waste products, and other substances throughout the body.
Together, interstitial fluid and plasma make up the extracellular fluid compartment, which is important for maintaining fluid balance and supporting the exchange of substances between cells and their environment. The extracellular fluid compartment is constantly in flux, with fluid moving in and out of it as needed to maintain homeostasis.
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A chemical equation is a statement using chemical __ that express both the identities and the relative __ of the reactants and products involved in a chemical or physical change
Answer:
the answer is here
Explanation:
if 0.75 grams of benzophenone was allowed to react with 0.20 grams of sodium borohydride, what is the percent yield if 0.42 grams of diphenylmethanol was produced?
The actual yield of diphenylmethanol was 0.42 grams. 0.75 grams of benzophenone was reacted with 0.20 grams of sodium borohydride to produce diphenylmethanol.
The percent yield is a measure of how efficient a chemical reaction is at producing the desired product. It is calculated by comparing the actual yield of the product to the theoretical yield, which is the amount of product that would be produced if the reaction proceeded perfectly. The percent yield can be calculated using the formula:
percent yield = (actual yield / theoretical yield) x 100%
The balanced equation for this reaction is:
C13H10O + 4H3B→C13H14O + 4B(OH)3
The molar mass of benzophenone is 182.2 g/mol, and the molar mass of diphenylmethanol is 198.3 g/mol. Using the stoichiometry of the balanced equation, the theoretical yield of diphenylmethanol can be calculated:
0.75 g benzophenone * (1 mol benzophenone / 182.2 g benzophenone) * (1 mol diphenylmethanol / 1 mol benzophenone) * (198.3 g diphenylmethanol / 1 mol diphenylmethanol) = 0.81 g diphenylmethanol
Therefore, the percent yield of the reaction can be calculated as:
percent yield = (0.42 g / 0.81 g) x 100% = 51.9%
The percent yield of this reaction is relatively low, indicating that there may have been some loss of product or incomplete conversion of reactants. Factors such as side reactions, impurities, and incomplete mixing can all contribute to a lower yield.
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What is the chemical formula for water?
Answer:
H2O
Explanation:
Answer:
H2O
Explanation:
The chemical formula for water is H2O, meaning it is made up of 2 hydrogen atoms and 1 oxygen atom.
What is the purpose of using the refractometer in today's experiment?
To determine the solubility of D-limonene in liquid CO
To determine the refractive index of D-limonene and characterize the sample.
To determine the specific rotation of D-limonene.
To determine the chirality of D-limonene.
To determine the enantiomeric excess (% ee) of D-limonene.
The purpose of using the refractometer in today's experiment is to determine the refractive index of D-limonene and characterize the sample.
A refractometer is a laboratory instrument that measures the refractive index of a substance, which is a measure of how much the substance bends light. Refractometers are commonly used in various fields such as chemistry, physics, biology, and agriculture, to determine the composition, concentration, and purity of a sample.
In this experiment, the refractometer is being used to determine the refractive index of D-limonene, which is a clear liquid hydrocarbon that is commonly used as a solvent and flavoring agent. The refractive index of D-limonene can provide information about the purity and composition of the sample, and it can also be used to identify the substance.
The refractive index is determined by measuring the angle of refraction of a beam of light passing through the sample. The angle of refraction is then used to calculate the refractive index of the substance. The refractive index of a substance is dependent on its chemical composition and can be used to distinguish between different compounds.
the refractometer is an important instrument for characterizing the properties of a sample, and in this experiment, it is being used to determine the refractive index of D-limonene and provide information about the purity and composition of the sample.
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what is the relationship between absorbance and concentration?
The concentration of a chemical influences absorbance. A substance's absorbance relates to its concentration. This is true because the quantity of light absorbed depends on the number of molecules with which light interacts.
The relationship between the absorbance and the concentration (c) of the sample solution employed in the experiment is straightforward. The width of the cuvette (l), which is equal to the length of the light path (l), has a direct relationship with absorbance. They are negatively correlated; as concentration rises, absorbance falls. Using Lambert's Beer Law, it is demonstrated that given a clear but colored solution, the relationship between absorbance and concentration is directly proportional. Increased particle density increases light absorption.
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indentify the type of scientific knowledge represented by each statement law ,theory, hypothesis
1. All objects fall to the ground at the same rate regardless of their mass. Law: This is a statement of Newton’s law of gravity, which states that the force of gravity is equal for all objects regardless of their mass.
What is the gravity law of Newton?According to Newton's law of gravity, every particle in the cosmos is drawn to every other particle with a force that is inversely proportional to the square of the distance between them and directly proportional to the product of their masses. Sir Issac Newton created this law of gravity in 1687. According to this law, the gravitational force is always attracting and works along the line connecting the two particles. In the formula F=Gm1m2/r2, where G is the universal gravitational constant, m1 and m2 are the masses of the two interacting particles, and r is the distance between them, the gravitational force's magnitude is given.
This law has been used to explain the motion of the planets, moons, and other celestial bodies and is thought to be crucial to comprehending the motion of bodies in the universe.
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Question
In the diagram, which letter represent the transition from solid to liquid?
Responses
A. A
B. B
C. C
D. D
The letter represent the transition from solid to liquid E. E.
What is the transition ?Transition is a process of change from one state or condition to another. It is a fundamental element of life, as it allows us to move forward, adapt, and develop. Transition can be physical, emotional, spiritual, or even intellectual. It can involve a change in environment, relationships, beliefs, roles, or responsibilities. Transition can be gradual, or it can happen suddenly. It can be difficult and require a lot of effort, or it can be relatively easy. Transition can be a positive experience, or it can be a difficult experience. Regardless of the form it takes, transition is a necessary part of life and growth.
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a piece of charcoal is found to contain 30% of the carbon 14 that it originally had. when did the tree die from which the charcoal came? use 5600 years as the half-life of carbon 14
The time when the tree die from which the charcoal came is 1.02×10⁻⁴ years. if half-time of carbon-14 is 5600years.
An amount is dependent upon exponential decay on the off chance that it diminishes at a rate relative to its ongoing worth. Emblematically, this interaction can be communicated by the accompanying differential equation, where N is the amount and λ (lambda) is a positive rate called the dramatic rot steady, crumbling consistent, rate steady, or change consistent: dN/dt=-λN. The answer for this situation (see deduction beneath) is: N(t)=N₀e⁻[tex]\frac{k}{t}[/tex], where N(t) is the amount at time t, N₀ = N(0) is the underlying amount, that is to say, the amount at time t = 0.
We know that exponential decay is given
A[tex]_t[/tex] = A₀ e⁻[tex]\frac{k}{t}[/tex] where K is decay constant.
We firstly find decay constant by using the half life-time
We know that t=ln2/k where t is half life time .Since,t=5600years given
=>5600=ln2/k
=>k=(ln2/5600)years
Now,it is given that at any particular instant amount of charcoal remain is 30 % of initial amount.
So, (30/100)A₀=A₀e⁻[tex]\frac{k}{t}[/tex]
Here,k=(ln2/5600)years
=>30/100=e⁻ [tex]\frac{ln2/5600}{t}[/tex]
Taking ln on both sides of equation,we get
=>ln(30/100)=ln(e⁻ [tex]\frac{ln2/5600}{t}[/tex])
=>ln30-ln 100= - ln2/5600t
=>3.40 - 4.60 = -0.693/5600t
=> - 1.205 = -0.693/5600t
=>t=0.693/ (1.205×5600)
=>t=0.693 / 6748years
=>t=0.000102years or 1.02×10⁻⁴ years.
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which of the following substances is least likely to dissolve in water? question 4 options: ch3(ch2)8ch2oh o double bonded with ch3(ch2)9ch ccl4 hoch2ch2oh chcl3
[tex]CCl_4[/tex] is the least soluble in water because it is a non-polar molecule that lacks a significant dipole moment and therefore does not interact well with polar water molecules.
The term "dissolve" describes a substance's capacity to combine uniformly with another substance, usually a liquid like water. In order for a substance to dissolve in water, its molecules must engage in molecular interactions with the water molecules that enable the two substances to combine. In most cases, this entails the creation of hydrogen bonds between the molecules of the solute and the water, enabling the solute to be encircled by water molecules and dispersed uniformly throughout the solution. The polarity, molecular makeup, and intermolecular interactions of a substance, among other things, affect its capacity to dissolve in water.
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The actual question is:
Which of the following substances is least likely to dissolve in water?
[tex]CHCl_3[/tex], [tex]CCl_4[/tex], [tex]CH_3(CH_2)_8CH_2OH[/tex], [tex]HOCH_2CH_2OH[/tex], [tex]CH_3(CH_2)_9COH[/tex]
A reaction and its experimentally determined rate law are represented above. A chemist proposes two different possible mechanisms for the reaction, which are given below.
Mechanism 1
X2 → 2 X (slow)
X + Y2 → XY2 (fast) X + XY2 → X2Y2 (fast)
Mechanism 2
X2 → 2 X (slow)
X + Y2 → XY + Y (fast) X + XY → X2Y (fast)
X2Y + Y → X2Y2 (fast) Based on the information above, which of the following is true?Both mechanism 1 and 2 are consistent with the rate law.Only mechanism 2 is consistent with the rate law.Neither mechanism 1 nor mechanism 2 is consistent with the rate law.Only mechanism 1 is consistent with the rate law
As mechanism 2 matches the given rate law, the correct answer is: only mechanism 2 is consistent with the rate law.
To determine which mechanism is consistent with the experimentally determined rate law, we need to check if the predicted rate law for each mechanism matches the given rate law.
The given rate law is: rate = k [X][Y₂]
Mechanism 1:
The slow step is the formation of X radicals from X₂, which is a bimolecular reaction. The intermediate X formed in the first step then reacts with Y₂ to form XY₂, and this intermediate reacts with X to form the final product X₂Y₂. Since the rate-determining step involves only X₂, we can assume that the rate law is determined by the concentration of X₂ only, and the rate law for mechanism 1 is therefore: rate = k[X₂]. This does not match the given rate law, so mechanism 1 is not consistent with the rate law.
Mechanism 2:
The slow step is again the formation of X radicals from X₂. The intermediate XY formed in the second step then reacts with Y to form X₂Y, and this intermediate reacts with Y to form the final product X₂Y₂. The rate-determining step involves X₂, XY, and Y, so we can write the rate law for mechanism 2 as:
rate = k [X₂][XY][Y].
Simplifying this rate law using the equilibrium constant for the fast equilibrium XY₂ ⇌ XY + Y₂, we can rewrite it as:
rate = k [X₂][Y₂]/K
This matches the given rate law, so mechanism 2 is consistent with the rate law.
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what type of bonding creates a substance that has the ability to conduct electricity when solid?
Metallic bonding is a common characteristic of a material that may conduct electricity when it is solid. The movement of electrical power or charge is known as electricity.
Metallic bonding is the kind of bonding that results in a material with the capacity to conduct electricity when it is solid. The valence electrons of metal atoms become delocalized and free to roam about the crystal lattice during metallic bonding, forming a "sea" of electrons. As they are able to transfer electricity through solid materials, these delocalized electrons are what give solid materials their electrical conductivity. Copper, aluminium, and gold are a few examples of metals that display metallic bonding and electrical conductivity in the solid form. A fundamental component of the natural world, electricity is also one of the most extensively utilised energy sources.
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what is the oxidation state of an individual sulfur atom in so32− ?
The oxidation state of an individual sulfur atom in SO32- (sulfite ion) is +4.
The oxidation state of an element in a chemical species is a measure of the degree of oxidation (loss of electrons) or reduction (gain of electrons) of that element in the species. In general, the oxidation state of an element in a neutral compound is zero, while in an ion, it is equal to the charge on the ion.
In the sulfite ion, SO32-, the sulfur atom has an oxidation state of +4. This means that it has lost four electrons compared to its neutral state.
The three oxygen atoms in the ion have an oxidation state of -2 each, so their total contribution to the charge on the ion is -6. To balance this, the sulfur atom must have a charge of +6, which is achieved by assigning an oxidation state of +4 to the sulfur atom.
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which example involves a colligative property? responses pouring salt on an icy sidewalk to make it free of ice pouring salt on an icy sidewalk to make it free of ice transferring some of a concentrated solution into a dilute solution transferring some of a concentrated solution into a dilute solution bringing a carbonated beverage to room temperature bringing a carbonated beverage to room temperature heating a pure solvent to boiling
Pouring salt on an icy sidewalk to make it free of ice is an example of a colligative property. Colligative properties are properties of solutions that depend on the concentration of solute particles, but not on their identity.
Four common colligative properties are:
Freezing point depression: The freezing point of a solution is lower than the freezing point of the pure solvent.Boiling point elevation: The boiling point of a solution is higher than the boiling point of the pure solvent.Osmotic pressure: The pressure required to prevent osmosis, the flow of solvent from a region of low solute concentration to a region of high solute concentration, across a semipermeable membrane.Vapor pressure lowering: The vapor pressure of a solution is lower than the vapor pressure of the pure solvent.Pouring salt on an icy sidewalk to make it free of ice is an example of freezing point depression. The salt dissolves in the water on the surface of the ice and forms a solution. The presence of salt in the water lowers the freezing point of the water, causing it to melt even at temperatures below the normal freezing point of pure water. This effect is due to the increased number of solute particles in the solution, which interferes with the formation of the crystal lattice of ice.
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match the following aqueous solutions with the appropriate letter from the column on the right. fill in the blank 1 1. 0.22 m bas a. lowest freezing point fill in the blank 2 2. 0.19 m niso4 b. second lowest freezing point fill in the blank 3 3. 0.20 m nh4br c. third lowest freezing point fill in the blank 4 4. 0.34 m ethylene glycol(nonelectrolyte) d. highest freezing point
0.22 M BaS -> d. highest freezing point0.19 M NiSO4 -> c. third lowest freezing point0.20 M NH4Br -> b. second lowest freezing point0.34 M Ethylene Glycol (nonelectrolyte) -> a. lowest freezing point
When a solute is added to a solvent, it lowers the freezing point of the solution. The extent to which the freezing point is lowered depends on the concentration of the solute particles in the solution. A higher concentration of solute particles leads to a greater decrease in the freezing point, resulting in a lower freezing point. The freezing point of a solution is directly proportional to the concentration of solute particles. Among the given solutions, the ethylene glycol solution will have the lowest freezing point as it is a nonelectrolyte and will not dissociate into ions in solution. The rest of the solutions contain electrolytes and will dissociate into ions in solution, increasing the concentration of solute particles and decreasing the freezing point. The highest freezing point will be observed in the BaS solution, which has the highest concentration of solute particles, while the NH4Br solution has a lower concentration of solute particles and will have the second lowest freezing point. The NiSO4 solution will have a slightly lower concentration of solute particles and will have the third lowest freezing point.
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can you substitute confectioners sugar for granulated sugar.true/false
The answer is true, confectioners sugar can be substituted for granulated sugar but it may not always be an exact 1:1 substitution.
Confectioners sugar (also known as powdered sugar or icing sugar) can be substituted for granulated sugar in some recipes, but it may not always be an exact 1:1 ratio substitution.
Confectioners sugar is a very fine powder that contains cornstarch, which is added to prevent caking. Due to its fine texture, it can dissolve quickly in recipes and can add a slightly different texture to baked goods. It can also affect the sweetness level of the recipe as it usually contains cornstarch or other additives, which can also influence the texture of the final product.
In general, substituting confectioners sugar for granulated sugar works best in recipes that don't require the sugar to dissolve completely, such as frosting or glazes. For recipes that require the sugar to dissolve, such as in baking or making meringues, it's best to use granulated sugar.
So, the answer is "True", but the substitution may not be appropriate for all recipes.
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which best describes the pka of a weak acid? choose one: a. pka values change over the course of a titration. b. the pka value depends on the concentration of the molecule present. c. the pka value depends on the ph. d. the pka is an intrinsic property of a molecule in question and depends on how tightly bound the acidic h is.
For a weak acid, the [tex]pk_a[/tex] value is an intrinsic property of the molecule and depends on how tightly bound the [tex][H^+][/tex] is.
In chemistry, an intrinsic property is a property of a substance that is independent of the amount of the substance present. Such properties are mainly dependent on chemical composition and structure.
The [tex]pk_a[/tex] value is the negative base 10 logarithm of the acid dissociation constant ([tex]k_a[/tex]) of a solution.
[tex]pk_a=-log_{10}(k_a)[/tex].
As the acid dissociation constant ([tex]k_a[/tex]) of a solution is an intrinsic property, hence the [tex]pk_a[/tex] value is also an intrinsic property.
The acid dissociation constant ([tex]k_a[/tex]) of a solution depends on the fact that if the acidic hydrogen [tex][H^+][/tex] is tightly bounded, then the value of [tex]k_a[/tex] will be decreased, which leads to the increase in the value of [tex]pk_a[/tex].
Hence, for a weak acid, the [tex]pk_a[/tex] value is an intrinsic property of the molecule and depends on how tightly bound the [tex][H^+][/tex] is.
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What can an element in activity series replace?
An element in activity series can replace the more reactive elements Because of this, the single replacement reaction occurs.
The activity series is defined as a list of elements in decreasing order of their reactivity. In a single replacement reaction, a given element is capable of replacing an element that is below it in the activity series. It can be used to predict if a reaction will occur. This reactions only occur when the element that is doing the replacing is more reactive than the element that is being replaced. It is useful to have a list of elements in order of their relative reactivities. The activity series defined as a list of elements in decreasing order of their reactivity. Since metals replace other metals while nonmetals replace other nonmetals and elements replace elements they each have a separate activity series.
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which of the gases has the fastest‑moving molecules, on average, at a given temperature?
HBr
NO2
C2H6
They all have same average speed
C2H6 is the gas having the fastest‑moving molecules, on average, at a given temperature because of its lower molecular mass
With the chemical formula C 2H 6, ethane is an organic chemical substance. Ethane is a colourless and odourless gas at ordinary temperature and pressure. Ethane is separated from natural gas on an industrial scale, and it is produced as a by-product of the petrochemical process used to refine crude oil.
The mass of a certain molecule is its molecular mass, which is expressed in daltons. Because different isotopes of an element 30.07 g in 1 mole C2H6 are present in different molecules of the same chemical, their molecular weights might vary. As a result, we state that ethane has a molar mass of 30.07 g/mol (grammes per mole).
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The voltage produced by the colorimeter is __________ to the absorbance of the sample and ____________ to the light intensity.A) Directly proportional, indirectly proportionalB) Directly proportional, directly proportionalC) Indirectly proportional, indirectly proportionalD) Indirectly proportional, directly proportionalE) None of the above
E) None of the above is the correct answer. The voltage produced by the colorimeter is logarithmically related to the absorbance of the sample and proportional to the light intensity.
The study of measuring the concentration of a coloured substance in a solution is known as colorimetry. A colorimeter is a tool that is sensitive to light. It is used to gauge the amount of light that passes through a liquid sample both transmittance and absorption. During colour measurement, the fluctuation in electromagnetic radiation's intensity in the visible wavelength area of the spectrum as a result of transmission or reflection by an object or solution is counted. Such a test can help determine the concentration of chemicals since the amount and colour of light that is absorbed or transmitted relies on the properties of the solution, including the number of particles in it.
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liquid water is more dense than ice because a. a liquid h 20 molecule has more mass than an ice h 20 molecule b. a chemical change occurs when ice melts that causes the mass of water to increase c. when ice melts there is an increase in the amount of water molecules d. there are a greater number of h 20 molecules per unit of volume in liquid water than ice
The correct answer is "d. there are a greater number of H2O molecules per unit of volume in liquid water than ice."
The density of a substance is defined as its mass per unit volume. In general, liquids are more dense than solids because the molecules in a liquid are more closely packed together and have more freedom to move than the molecules in a solid. When ice (a solid) melts to form liquid water, the water molecules are no longer held in a fixed arrangement and can move more freely. This increased mobility results in a more compact packing of the molecules, leading to an increase in the density of the liquid water compared to ice.In other words, there are more H2O molecules per unit of volume in liquid water than in ice, making liquid water more dense than ice.
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What are the components in cassiterite
Answer:
Minerals and rocks
Cassiterite is a tin oxide mineral (SnO2) and the principal source for tin metal (79.6% Sn). The color is shining black, brownish-black (Fig. 1.34), reddish brown, gray, red, white, and rarely colorless. The crystal system is tetragonal with very common twinning.
how do mafic and felsic minerals and rocks differ from each other?
Mafic and felsic minerals and rocks are both types of igneous rocks, which form when magma or molten rock cools and crystallizes.
Mafic minerals and rocks are composed of dark-colored minerals, such as olivine, pyroxene, amphibole, and biotite. These minerals tend to be high in magnesium and iron, and are relatively low in silica. As a result, mafic rocks are denser and heavier than felsic rocks.
Felsic minerals and rocks, on the other hand, are composed of light-colored silicate minerals, such as quartz, feldspar, and muscovite. These minerals are high in silica and low in magnesium and iron. As a result, felsic rocks are less dense and lighter than mafic rocks. Felsic rocks often form in more explosive volcanic eruptions, while mafic rocks form in quieter eruptions. Finally, felsic rocks tend to have a light-colored or white appearance, while mafic rocks are typically dark gray or black.
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Which best describes Lenny’s error?
In Step 1, he should have found the square root of 400 J instead of squaring 8 m/s.
In Step 1, he should have multiplied 8 m/s by 2 instead of squaring it.
In Step 2, he should have divided 64 m2/s2 by 400 J instead of dividing 400 J by 64 m2/s2.
In Step 3, he should have multiplied 6.25 J per m2/s2 by 2 instead of dividing it by 2.
In Step 3, he should have multiplied 6.25 J per m2/s2 by 2 instead of dividing it by 2 best describes Lenny’s error. Therefore, option D is correct.
What is kinetic energy ?The term kinetic energy is defined as the energy that it possesses due to its motion. It is also defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.
The object contain an kinetic energy,
Given Mass of an object = 400 J
Energy moving at a velocity = 8 m/s.
Ek = 1/2 mv²
= 400J = 1/2 × m 64
= 400J/ 64= 1/2 m
= 6.25 × 2
= 12.25kg
So, In the step 3 ,he should have multiplied 6.25 J per m²/s² by 2 instead of dividing it by 2.
Thus, option D is correct.
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Your question is incomplete, most probably your question was
Lenny wrote the steps he used to find the mass of an object with 400 J of energy moving at a velocity of 8 m/s.
1. Find the square of 8 m/s, which is 64 m2/s2.
2. Divide kinetic energy, 400 J, by 64 m2/s2, which is 6.25 J per m2/s2.
3. Divide 6.25 J per m2/s2 by 2 to get a mass of 3.125 kg.
Which best describes Lenny’s error?
A. In Step 1, he should have found the square root of 400 J instead of squaring 8 m/s.
B. In Step 1, he should have multiplied 8 m/s by 2 instead of squaring it.
C. In Step 2, he should have divided 64 m2/s2 by 400 J instead of dividing 400 J by 64 D. m2/s2.
In Step 3, he should have multiplied 6.25 J per m2/s2 by 2 instead of dividing it by 2.
a saline solution was made by dissolving 1.69 g sodium chloride in 200 ml distilled water. what is the concentrtation of salt in this soution
a saline solution was made by dissolving 1.69 g sodium chloride in 200 ml distilled water,then the concentration of salt in the solution is 8.45 g/L.
To find the concentration of salt in the solution, we need to divide the amount of salt (in grams) by the volume of the solution (in liters).
First, we need to convert the volume from milliliters (mL) to liters (L):
200 mL = 0.2 L
Next, we can calculate the concentration of salt:
concentration = amount of salt / volume of solution
concentration = 1.69 g / 0.2 L
concentration = 8.45 g/L
Therefore, the concentration of salt in the solution is 8.45 g/L.
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a chef plans to mix vinegar with italian dressing. the italian dressing contains vinegar. the chef wants to make milliliters of a mixture that contains vinegar. how much vinegar and how much italian dressing should she use?
chef should use 478.04 ml of Italian dressing and 21.96 ml of vinegar to make 500 ml of a mixture that contains 2% vinegar
To solve this , we need to use the concept of the concentration of the solution.
Let's assume that the concentration of vinegar in the Italian dressing is C1 and that the chef wants to make V milliliters of a mixture that contains vinegar.
Let's also assume that the concentration of vinegar in the final mixture is C2.
To find out how much vinegar and Italian dressing the chef should use, we can use the following formula:
C1V1 + C2V2 = C2V
where V1 is the volume of the Italian dressing that the chef should use, and V2 is the volume of vinegar that the chef should use.
We know that the concentration of vinegar in the Italian dressing is C1, so the concentration of the other ingredients in the Italian dressing is 1 - C1.
Let's assume that the chef wants to use x milliliters of Italian dressing and y milliliters of vinegar.Using the formula above, we can set up the following equation:
C1 * x + 1 * y = C2 * V
x + y = V
We have two equations and two unknowns, so we can solve for x and y.
y = (C2 - C1) * V / (1 - C1)
x = V - y
Substituting the values of C1, C2, and V, we get:
y = (0.05 - 0.02) * 500 / (1 - 0.02) = 21.96 ml
x = 500 - 21.96 = 478.04 ml
Therefore, the chef should use 478.04 ml of Italian dressing and 21.96 ml of vinegar to make 500 ml of a mixture that contains 2% vinegar.
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1. how many molecules of phosphorus pentachloride are present in 8.70 grams of this compound ? molecules.
There are approximately 2.52 x 10^22 molecules of phosphorus pentachloride present in 8.70 grams of this compound.
As per the question given,
To determine the number of molecules of phosphorus pentachloride present in 8.70 grams of this compound, we need to use the following steps:
Determine the molar mass of PCl5, which is the sum of the atomic masses of one mole of P and five moles of Cl:
M(P) = 30.97 g/mol
M(Cl) = 35.45 g/mol
M(PCl5) = 30.97 + 5(35.45) = 208.23 g/mol
Convert the given mass of PCl5 to moles using its molar mass:
moles of PCl5 = 8.70 g / 208.23 g/mol = 0.0418 mol
Convert the number of moles of PCl5 to molecules using Avogadro's number, which is 6.022 x 10^23 molecules/mol:
molecules of PCl5 = 0.0418 mol x 6.022 x 10^23 molecules/mol = 2.52 x 10^22 molecules
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when the bromothymol blue solution turned from blue to yellow what did that tell us about the ph of the solution?
Because the pH of amniotic fluid is usually > 7.2, bromothymol turns blue when it comes into contact with the fluid leaking from the amniotic membrane. The pH of the vagina is usually acidic, so blue indicates the presence of amniotic fluid.
Bromothymol blue is a pH indicator. It is mainly used in applications where substances with a relatively neutral pH (approximately 7) must be measured. It is commonly used to measure the presence of carbonic acid in a liquid. It is usually sold in solid form as the sodium salt of an acid indicator.
Bromothymol blue can be used to monitor photosynthetic activity or as an indicator of respiration (turns yellow when CO2 is added). A common demonstration of the properties of the BTB pH indicator involves exhaling into a neutral BTB solution through a tube. The solution changes color from green to yellow as CO2 is absorbed into the solution by breathing to form carbonic acid. Therefore, the BTB is commonly used in science classes to prove that the more muscles involved, the higher the CO2 emission.
It can also be used in laboratories as a dye for biological preparations. At this point the bromothymol is already blue and uses a few drops of BTB on the waterslide. Mix the sample with the blue BTB solution and fix it on a glass slide with a coverslip. It is sometimes used to identify cell walls or nuclei under a microscope.
Bromothymol is used in obstetrics to detect premature rupture of the amnion. Since the pH of amniotic fluid is typically > 7.2, bromothymol turns blue when it comes in contact with amniotic fluid. The pH of the vagina is usually acidic, so blue indicates the presence of amniotic fluid. The test may be false positive in the presence of other alkaline substances such as blood or semen, or in the presence of bacterial vaginosis.
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Select the gas with the highest average kinetic energy per mole at 298 K.
a. carbon dioxide
b. all have the same kinetic energy
c. hydrogen
d. water
e. oxygen
c. hydrogen. A gas's average kinetic energy is related to its temperature. To determine which gas has the highest average kinetic energy per mole at 298 K, we must examine each gas's.
molar mass as well as its associated speed distribution. The following equation gives the root-mean-square (RMS) speed of a gas RMS speed is sqrt((3RT) / M). where R denotes the gas constant, T is the temperature in Kelvin, and M denotes the gas's molar mass. We can use this equation to compute the RMS speed of each gas at 298 K and compare it to see which gas has the highest average kinetic energy per mole. a. The molar mass of carbon dioxide is 44.01 g/mol. Its average speed at 298 K is: RMS speed = sqrt((3 * 8.31 J/(mol*K) * 298 K) / 44.01 g/mol) = 408 m/s b. All gases have the same kinetic energy, regardless of their molar mass, so this answer is incorrect. c. Hydrogen has a molar mass of 2.02 g/mol. Its RMS speed at 298 K is: RMS speed = sqrt((3 * 8.31 J/(mol*K) * 298 K) / 2.02 g/mol) = 1,926 m/s/.
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03 which type of silicate has the greatest proportion of oxygen atoms shared by pairs of adjacent tetrahedra
The most oxygen atoms shared by pairs of neighbouring tetrahedra are found in double chain silicates, which is the most common kind of silicate.
This particular silicate consists of silicon atoms bound to other silicon atoms in a chain with oxygen atoms, with oxygen atoms forming the corners of the tetrahedra. As compared to other forms of silicates, these chains share oxygen atoms with neighbouring chains, leading to a higher percentage of oxygen atoms shared by pairs of adjacent tetrahedra. Due to the lack of connectedness between their tetrahedral units, other silicate types, such as sheet silicates and framework silicates, have a lower percentage of oxygen atoms shared by pairs of neighbouring tetrahedra. Because of this, double chain silicates have a tendency to be more dense and structurally complicated than other silicate kinds.
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