Answer:
13.5g
Explanation:
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 138.8g of aluminium is needed to react with 640g of iron oxide.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
Mathematically, the balanced equation can be written as
3Fe[tex]_2[/tex]O[tex]_3[/tex] + 4Al [tex]\rightarrow[/tex] Al[tex]_2[/tex]O[tex]_3[/tex] + 6Fe
number of moles of iron oxide= 640/159.6
=4.01
number of moles of aluminium =(4/3)×4.01
=5.34moles
mass of aluminium =5.34×26
=138.8g
Therefore, 138.8g of aluminium is needed to react with 640g of iron oxide.
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why do we adjust coefficients when balancing chemical equations and not subscripts?
Answer:
By changing the coefficients you change the amount you have of certain compounds in the equation, whereas changing the subscript would change what compounds are actually in the equation because it would change the ratio of how many atoms of each element are in a compound.
For Example:
Outside of Balancing Equations, [tex]NO_{2}[/tex] (Nitrite) and [tex]NO_{3}[/tex] (Nitrate) are different because one forms a strong acid while the other forms a weak acid based on how many oxygen atoms are added to the compound. So in a chemical equation, if you change the subscripts, you change the entire compound so your reaction may be with a weak acid instead of a strong acid and give you a different product. Meanwhile, changing the coefficient changes the amount of the compound you have for the reaction in order to maintain the Conservation of Mass Law.
in a battery that uses a licoo2 cathode approximately 50% of the lithium migrates from the cathode to the anode on charging. in a battery that uses a limn2o4 cathode what fraction of the lithium in limn2o4 would need to migrate out of the cathode to deliver the same amount of lithium to the graphite anode?
Answer:
92.4%
Explanation:
Assume 100g of the cathode material. The LiCoO2 cathode has 7.09 g of Li. If half of Li migrates during charging, 3.55g Li migrates. 100g of the LiMn2O4 cathode contain 3.84g of Li. The fraction of lithium in LiMn2O4 that would need to migrate out of the cathode to deliver the same amount of lithium to the graphite anode:
(3.55g/ 3.84g ) * 100% = 92.4%
From electrolysis, 92.4% would need to migrate out of the cathode to deliver the same amount of lithium to the graphite anode.
What is electrolysis?
Electrolysis is a technique that uses direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. The voltage that is needed for electrolysis to occur is called the decomposition potential.
Assume 100 g of the cathode material. The LiCoO₂ cathode has 7.09 g of Li. If half of Li migrates during charging, 3.55 g Li migrates. 100 g of the LiMn₂O₄cathode contain 3.84 g of Li. The fraction of lithium in LiMn₂O₄ that would need to migrate out of the cathode to deliver the same amount of lithium to the graphite anode:(3.55 g/ 3.84 g ) × 100% = 92.4%
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Part C
Next Emmerson pours dark blue–colored water on the soil around the well. The pictures show how his model looked over time. What do you observe?
Answer:
I obseve that the water is turnign a little green in the begining but when the water hit the gravel and dirt it became realy blue
Explanation:
Mark brainliest idc
Answer:
I observe that the water started off by turning green and the higher the water went the more blue it had gotten.
Explanation: lazy answer but if you want an answer here you go:)
What is function of phylloclade
In some plants such as Cactuses, the stem is flattened and green and carries out the function of the leaf. Such a stem, adapted for the manufacture of food is called phylloclade. The leaves here are reduced or modified into spines to lessen the transpiring surface.
Explain how food is transformed to energy for our bodies.
How does an electric generator work?
Answer:
A conductor coil (a copper coil tightly wound onto a metal core) is rotated rapidly between the poles of a horseshoe type magnet. ... The magnetic field will interfere with the electrons in the conductor to induce a flow of electric current inside it.
4. Which elements have a completely full outermost energy level?
Answer:
Helium (He), neon (Ne), and argon (Ar), as group 18 elements, have outer electron shells that are full or satisfy the octet rule. This makes them highly stable as single atoms. Because of their non-reactivity, they are called the inert gases or noble gases.
Explanation:
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do you think organisms who live in the artic would survive in the desert? Do you think organisms in the desert would survive in the artic? Why or why not?
Answer:
I'd say probably not
Explanation:
Organisms have evolved to survive and thrive in particular environmental conditions, specifically focusing on food supply, temperature, terrain, etc.. Therefore, desert animals would not be equipped with the insulation to survive in cold climates like the artic, and would freeze to death, and artic animals would most likely die from heat exhaustion in the desert. Additionally, fish, which is a main food source for articles animals, are not available in the desert, and it's the same case for desert animals in the artic. Finally, those organisms' enzymes and proteins, which make up their being and are the reason they can function, are only optimal in the temperature range in which they normally live; therefore, switching to such drastically different climate would result in their enzymes denaturing and their cell and eventual organism death.
what is the strongest type of intermolecular forces present between a stearic acid molecule and a water molecule?
The bond and the force present between molecules is called intermolecular force. A hydrogen bond is present between the stearic acid and a water molecule.
What are hydrogen bonds?Hydrogen bonds are the intermolecular force that forms a dipole-dipole interaction with an electronegative atom in the presence of the lone pair of electrons.
In stearic acid, [tex]\rm C_{18}H_{36}O_{2}[/tex], hydrogen bonding exists between the oxygen and the hydrogen atom of the molecule.
Therefore, a hydrogen bond is present between stearic acid and the water molecule.
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Did you know that
1-7=0
Answer:
No I didn’t
Explanation:
why would someone need to find the relative density of an object?
Answer:
The relative densities of an object and the liquid it is placed in determine whether that object will sink or float. An object that has a higher density than the liquid it's in will sink. An object that has a lower density than the liquid it's in will float.
Explanation:
Hope it helps!
The relative densities of an object and the liquid it is placed in determine whether that object will sink or float. An object that has a higher density than the liquid it's in will sink. An object that has a lower density than the liquid it's in will float.
This principle is fundamental to understanding why objects float or sink in fluids and are commonly observed in everyday situations. For example, ships and boats float on water due to their design and the distribution of weight, while heavy materials like metal sink in water because their density is greater than that of water.
Therefore, The concept of relative densities and buoyancy has significant applications in various fields, including shipbuilding, architecture, swimming, and understanding the behavior of objects in liquids.
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count the atoms in the following example
Need answer ASAP
Answer:
32 atoms.
Explanation:
4 x 2 = 8 +
4 x 3(O3) = 12 +
4 x 3(SO3) = 12; 32
Calcule la molaridad de una solución acuosa de ácido sulfúrico (H₂SO₄) que se preparó al mezclar, en un recipiente aforado, 4 moles del ácido con suficiente agua hasta completar 8 litros de solución. *
0.4
0.6
0.3
0.5
Considerando la definición de molaridad, la molaridad de una solución acuosa de ácido sulfúrico (H₂SO₄) es 0.5 [tex]\frac{moles}{litro}[/tex].
La molaridad es una medida de la concentración de un soluto en una disolución que se define como el número de moles de soluto que están disueltos en un determinado volumen.
La molaridad de una solución se calcula dividiendo los moles del soluto por el volumen de la solución:
[tex]Molaridad=\frac{numero de moles de soluto}{volumen}[/tex]
La Molaridad se expresa en las unidades [tex]\frac{moles}{litro}[/tex].
En este caso, sabes que una solución acuosa se preparó al mezclar 4 moles del ácido con suficiente agua hasta completar 8 litros de solución. Entonces, sabes que:
número de moles de soluto= 4 molesvolumen= 8 litrosReemplazando en la definición de molaridad:
[tex]Molaridad=\frac{4 moles}{8 litros}[/tex]
Resolviendo:
Molaridad= 0.5 [tex]\frac{moles}{litro}[/tex]
Finalmente, la molaridad de una solución acuosa de ácido sulfúrico (H₂SO₄) es 0.5 [tex]\frac{moles}{litro}[/tex].
Aprende más:
https://brainly.com/question/17647411?referrer=searchResultshttps://brainly.com/question/21276846?referrer=searchResultsConsider the following chemical reaction.
3 Zn(C₂H₃O₂)₂(aq) + 2 Na₃PO₄(aq) → 6 NaC₂H₃O₂(aq) + Zn₃(PO₄)₂(s)
A chemist makes a solution of zinc acetate by dissolving 20.5 g Zn(C₂H₃O₂)₂ in 105 mL H₂O. What is the concentration of this zinc acetate solution?
The concentration of the zinc acetate, Zn(C₂H₃O₂) solution is 1.067 M
We'll begin by calculating the number of mole in 20.5 g of Zn(C₂H₃O₂)₂Mass of Zn(C₂H₃O₂)₂ = 20.5 g
Molar mass of Zn(C₂H₃O₂)₂ = 65 + 2[(12×2) + (3×1) + (16×2)]
= 65 + 2[59]
= 183 g/mol
Mole of Zn(C₂H₃O₂)₂ =?Mole = mass / molar mass
Mole of Zn(C₂H₃O₂)₂ = 20.5 / 183
Mole of Zn(C₂H₃O₂)₂ = 0.112 mole Finally, we shall determine concentration of Zn(C₂H₃O₂). This can be obtained as follow:Mole of Zn(C₂H₃O₂)₂ = 0.112 mole
Volume = 105 mL = 105 / 1000 = 0.105 L
Concentration of Zn(C₂H₃O₂)₂ =?Concentration = mole / Volume
Concentration of Zn(C₂H₃O₂)₂ = 0.112 / 0.105
Concentration of Zn(C₂H₃O₂)₂ = 1.067 MTherefore, the concentration of the zinc acetate, Zn(C₂H₃O₂) solution is 1.067 M
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kinetic energy increases as velocity ___
Answer:
square of it's speed
Explanation:
Answer:
kinetic energy increases as the square of its speed.
A sample of damp air in a 1.00 L container exerts a total pressure of 741.0 torr at 20 oC; but when it is cooled to -10 oC, the water vapor freezes to ice with neglegible pressure giving a pressure of 607.1 torr. How many molecules of water were present in the gas
From the information presented in the question, the number of molecules present of water present is obtained 2.41 × 10^21 molecules.
From the information we have;
Volume of the damp air = 1 L
Pressure of the damp air = 741.0 torr or 0.975 atm
Temperature of the gas = 20 oC + 273 = 293 K
R = 0.082 atm LK-1mol-1
Number of moles = ?
n =PV/RT
n = 0.975 × 1/0.082 × 293
n = 0.041 moles
Volume of water vapor = 1 L
Temperature of water = -10 oC + 273 = 263 K
Pressure of the gas = 607.1 torr or 0.799 atm
R = 0.082 atm LK-1mol-1
n= PV/RT
n = 0.799 × 1/ 0.082 × 263
n = 0.037 moles
Number of moles of water = 0.041 moles - 0.037 moles = 0.004 moles
If 1 mole = 6.02 × 10^23 molecules
0.004 moles = 0.004 moles × 6.02 × 10^23 molecules/1 mole
= 2.41 × 10^21 molecules
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What is true about the light shown above?
A. All of the light is refracted
B. All of the light is reflected
C. Some of the light is refracted, and some of the light is reflected
D. None of the light is refracted or reflected
Answer:
The answer is D. None of the light is refracted or reflected.
Explanation:
Just trust :)
Fill in blank.
Normal force is always ____
to the surface you object is resting on.
perpendicular
parallel
opposite
skewed
oncepts
4 List What are some of the physical properties
of stars?
Answer:
Brightness. Two characteristics define brightness: luminosity and magnitude. ...
Color. A star's color depends on its surface temperature. ...
Surface Temperature. ...
Size. ...
Mass.
Explanation:
there
What happens to the molecules that make up a chocolate chip as it is heated in the oven?
Answer:As thermal energy is transferred to the chocolate, its molecules vibrate faster and faster. Eventually they vibrate fast enough that they start to slide past each other and move around. As this happens, the chocolate changes from a solid to a liquid.
Explanation:
Answer:
it becomes
Explanation:
as a soggy liquid
that is how it becomes
liquid and little thick
as it is heated
hope it helps you
thank you
Which statement best describes the difference between a substance with a pH of 2.0 versus a substance with a pH of 4.0?
a
(1 point)
O The substance with a pH of 2.0 would have 100 times as many hydrogen ions per volume of water.
o The substance with a pH of 4.0 would have 100 times as many hydrogen ions per volume of water.
O The substance with a pH of 4.0 would have twice as many hydrogen ions per volume of water.
O The substance with a pH of 2.0 would have twice as many hydrogen ions per volume of water.
Answer:
The answer is the first one.
Explanation:
The lower a pH level the higher the the number hydrogen ions present in the acid's container.
ph = - log(H)
4 = - log(H)
- 4 = log(h)
10^-4 = H+
1 * 10^-4 = H +
ph = - log(H)
ph = 2
- 2 = log(H)
10^-2 = H
1*10^-2 = h
Something the power - 2 is 100 times greater than something with the power of -4
Answer:
the guy above is correct
Explanation:
I need help with the question below
Answer:
the answer is Crystal structures
how might rising atmospheric co2 concentrations lower the ph of the oceans?
Explanation:
As CO2 concentrations rise, excess CO2 is absorbed by the oceans. CO2 in the oceans can react chemically with water to form acid. ... The difference in pH units between two acidic solutions is three.
The gain of electrons by an element or ion in a reaction is called __.
A. fractionation
B. Disproportionation
C. Oxidation
D. Reducing
Answer:
Reduction
Explanation:
took the test
2. For each of the six elements aluminium (Al), boron (B), nitrogen (N), oxygen (O) phosphorus (P), sulfur (S), write down:
a. the period of the periodic table to which it belongs.
b. its group number in the periodic table.
c. its proton number (atomic number).
d. the number of electrons in one atom.
e. its electronic configuration.
f. the number of outer-shell electrons in one atom.
g. Which of the above elements would you expect to have similar properties?
Elements in the same group of the periodic table tend to have similar chemical properties
What is the periodic table?For Al;
a. Period: Period 3
b. Group: Group 13
c. Proton Number (Atomic Number): 13
d. Number of Electrons: 13
e. Electronic Configuration: 1s² 2s² 2p⁶ 3s² 3p¹
f. Number of Outer-Shell Electrons: 3
g. Similar Properties: Boron (B)
For Boron (B):
a. Period: Period 2
b. Group: Group 13
c. Proton Number (Atomic Number): 5
d. Number of Electrons: 5
e. Electronic Configuration: 1s² 2s² 2p¹
f. Number of Outer-Shell Electrons: 3
g. Similar Properties: Aluminium (Al)
For Nitrogen (N):
a. Period: Period 2
b. Group: Group 15
c. Proton Number (Atomic Number): 7
d. Number of Electrons: 7
e. Electronic Configuration: 1s² 2s² 2p³
f. Number of Outer-Shell Electrons: 5
g. Similar Properties: Phosphorus (P)
For Oxygen (O):
a. Period: Period 2
b. Group: Group 16
c. Proton Number (Atomic Number): 8
d. Number of Electrons: 8
e. Electronic Configuration: 1s² 2s² 2p⁴
f. Number of Outer-Shell Electrons: 6
g. Similar Properties: Sulfur (S)
For Phosphorus (P):
a. Period: Period 3
b. Group: Group 15
c. Proton Number (Atomic Number): 15
d. Number of Electrons: 15
e. Electronic Configuration: 1s² 2s² 2p⁶ 3s² 3p³
f. Number of Outer-Shell Electrons: 5
g. Similar Properties: Nitrogen (N)
For Sulfur (S):
a. Period: Period 3
b. Group: Group 16
c. Proton Number (Atomic Number): 16
d. Number of Electrons: 16
e. Electronic Configuration: 1s² 2s² 2p⁶ 3s² 3p⁴
f. Number of Outer-Shell Electrons: 6
g. Similar Properties: Oxygen (O)
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If you have a ring that contains 1.94 g of gold, how many atoms of gold are there in the ring?
Review the information from the documents you read for this assignment. Use what you learned to answer the following question. What were the major effects of a dust storm? Give your answer in at least four sentences.
Answer:
what people experienced during a dust storm
how people reacted to a dust storm
what people did after a dust storm
Explanation:
i passed
Answer:
what people experienced during a dust storm
how people reacted to a dust storm
what people did after a dust storm
Explanation:
Properties of gases are dependent upon the pressure, temperature, and volume of the container they are in, as well as the number of gas particles. true or false
Answer:
False
Explanation:
Those would affect physical properties not chemical properties.
which molecule or ion has a trigonal planar geometry around its central atom?
Answer:
Structure of boron trifluoride, an example of a molecule with trigonal planar geometry.
Explanation:
48. Categorize each of the elements in problem 47 as a
representative element or a transition metal
Will give brainliest :)
Answer:
The correct answer is a transition metal.
Explanation:
Hope it helps.
Comments:
Hearts and RatesMark me as Brainliest AnswerFollow MeAll the given elements are representative elements as they have valence electrons present in p -orbital except option a which has valence electron d-orbital and hence is not a representative element.
It is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.
Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.
The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.
Thus, all the given elements are representative elements as they have valence electrons present in p -orbital except option a which has valence electron d-orbital and hence is not a representative element.
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