Answer:
78.8%
Explanation:
The equation of the reaction is;
2 Al(s) + Fe2O3(aq) ------> Al2O3(aq) + 2Fe(s)
Number of moles in 20g of Al= 20g/27 g/mol = 0.74 moles
From the reaction equation;
2 moles of Al yields 2 moles of Fe
0.74 moles of Al yields 0.74 moles of Fe
Hence;
Mass of Fe produced = 0.74 moles of Fe * 56 g/mol
Mass of Fe produced = 41.44 g of Fe (This is the theoretical yield of Fe)
percent yield = actual yield/ theoretical yield * 100
actual yield = 32.67 grams of iron
percent yield = 32.67 g/41.44 g * 100
percent yield = 78.8%
Partial pressure of oxygen dissolved in blood is 50 mm Hg. That means that:
1. It exerts a force per cm^2 equal to that of a column of mercury with 1 cm^2 base and 50 mm height
2. It would be in equilibrium with gaseous oxygen that is at partial pressure of 50 mm Hg
3. Both (1) and (2)
4. Neither (2) or (2)
Answer:
The answer is "Option 2".
Explanation:
In this question, the balance with a partial 50 mm Hg pressure of gassing oxygen.In this, the base value is given in the cm that is incorrect because it is measured in mm.In this, the partial pressure of gas in the liquid is equal to the pure pressure of the gas.Magnesium metal reacts with oxygen gas
What is the initial appearance of Magnesium metal?
When Magnesium comes in contact with Oxygen, it reacts with Oxygen causing a layer of Magnesium Oxide on the metal. If Magnesium is burnt, it will cause a bright white light creating Magnesium Oxide.
The initial appearance of Magnesium is a ribbon with a layer of Magnesium Oxide.
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How long will it take a 500-W heater to raise the temperature of 400 g of water from 15.0 °C to 98.0
°C?
Explanation:
E=(98-15)×400×4.2
E=139440J
t=E/P
E=139440/500=278.88s
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What causes the recognition of an element from its energy signature?
O
A. Each element emits radiations at random frequencies.
B. Each element emits energy that can be transformed into sound.
C. Each element emits electromagnetic waves that travel faster than light.
D. Each element emits electromagnetic waves at a unique set of wavelengths.
Answer:
I'm so sorry if this is wrong but I think its B
What is Climate Change and how can it effect plants?
Answer:
Climate change will make plants—and us—thirstier. The combined effects of increased CO2 levels and warmer temperatures will increase water consumption by vegetation. That will lead to water declines in streams and rivers like the Ashepoo River in South Carolina
Explanation:
80 POINTS
Batteries, motors, and generators all demonstrate what concept?
Newton's Laws
Wave Speed
Conservation of Energy
Chemical Reactions
1. How many moles of carbon are in 2.25 * 10^22 atoms of carbon ?
Answer:
atoms of C? 2.25 x 1022 atoms C x 1 mole C = 0.037 mol C
Explanation:
How many moles of C are in 2.25 x 1022 atoms of C?
Taking into account the definition of Avogadro's number, 0.037 moles of carbon are 2.25×10²² atoms of carbon.
Definition of Avogadro's NumberAvogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023×10²³ particles per mole. Avogadro's number applies to any substance.
Amount of moles of carbons
In this case, you can apply the following rule of three: if 6.023×10²³ atoms are contained in 1 mole of carbon, then 2.25×10²² atoms are contained in how many moles of copper?
amount of moles of carbon= (2.25×10²² atoms × 1 mole)÷ 6.023×10²³ atoms
amount of moles of carbon= 0.037 moles
Finally, 0.037 moles of carbon are 2.25×10²² atoms of carbon.
Learn more about Avogadro's Number:
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What mass of sucrose is needed to make 300.0 mL of a 0.5 M solution? (molar mass=
342.34 g/mol)
In 1773 Benjamin Franklin, investigating the calming effect of oil on the water of a pond near London, observed that a teaspoonful of oil would cover about half an acre of the surface. From this information, estimate the height or thickness of an oil molecule in the floating film of oil. Then estimate the cross sectional area of an oil molecule in the floating film You may assume that Franklin used a lamp oil, like camphene, C10H16.
Required:
Calculate the thickness (in nm) of the surface film and the surface area (in nm2) occupied by an oleic acid molecule on water.
Answer:
a. 2.44 nm
b. 15.33 nm²
Explanation:
a. Calculate the thickness (in nm) of the surface film
Since the volume of a teaspoon equals V = 4.93 cm³ and the area of the oil film is half an acre = 1/2 × 4046.86 m² = 2023.43 m²
The volume of the oil film, V' equals the volume of the oil in the teaspoon, V
V' = Ah where A = cross-sectional area of oil film = 2023.43 m² = 2023.43 × 10⁴ cm² and h = height of oil film
So, V' = V
Ah = V
h = V/A
= 4.93 cm³/2023.43 × 10⁴ cm²
= 0.00244 × 10⁻⁴ cm
= 2.44 × 10⁻⁷ cm
= 2.44 × 10⁻⁷ cm × 1m/100 cm
= 2.44 × 10⁻⁹ m
= 2.44 nm
b. The surface area (in nm2) occupied by an oleic acid molecule on water.
Since the height of the oil film equals the diameter of the oil molecule, and the molecule is assumed to be a sphere of radius, r. Its surface area is thus A = 4πr²
r = h/2 = 2.44 nm/2 = 1.22 nm
A = 4πr²
A = 4π(1.22 nm)²
A = 4.88π nm²
A = 15.33 nm²
H2(g)+I2(s)→HI(s)H2(g)+I2(s)→HI(s) balance equations
Answer:
H2(g)+I2(s)→2HI(s)
Explanation:
Hello there!
In this case, according to the given information and unbalanced chemical reaction, we infer it must be balanced in agreement with the law of conservation of mass because the reactants side has two hydrogen and iodine atoms whereas the products side has just one. In such a way, by placing a 2 on HI, we obtain the following balanced reaction:
H2(g)+I2(s)→2HI(s)
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How many molecules does 1.25 grams of C2H4 represent?
Explanation:
hope the picture above make sense:)
What type of material is commonly used in 3d Printing?
O Wood
O Honey
O Plastics
O Stone
Don’t know pls help fast
Answer:
Plastics!!!!!
Explanation:
How do you print stone or honey or wood you melt plastic or filiment to print stuff
Three biologically important diatomic species, either because they promote or inhibit life, are
(a) CO,
(b) NO3 and
(c) CN-.
The first binds to hemoglobin, the second is a chemical messenger, and the third interrupts the respiratory electron transfer chain. Their biochemical action is a reflection of their orbital structure. Deduce their ground state electron configurations.
Answer:
See Explanation
Explanation:
We can write the molecular orbital configuration of molecules in the same way as we write the orbital electron configuration of atoms. The valence electrons in the molecule are filled into molecular orbitals of appropriate energy in accordance to the Aufbau principle.
For CO;
σ2s2, σ*2s2, Π2py2, Π2pz2, σ2px2
For NO;
σ2s2, σ*2s2, Π2px2, Π2py2, σ2pz2, Π*2px1
For CN-;
σ2s2, σ*2s2, Π2px2, Π2py2, σ2pz2
These are the ground state electron configurations of these molecules.
What volume of 10 M HCl must be used to create 100 mL of a 5 M solution.
Answer: A volume of 50 mL of 10 M HCl must be used to create 100 mL of a 5 M solution.
Explanation:
Given: [tex]V_{1}[/tex] = ?, [tex]M_{1}[/tex] = 10 M
[tex]V_{2}[/tex] = 100 mL, [tex]M_{2}[/tex] = 5 M
Formula used to calculate the volume is as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}[/tex]
Substitute the values into above formula as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}\\10 M \times V_{1} = 5 M \times 100 mL\\V_{1} = 50 mL[/tex]
Thus, we can conclude that a volume of 50 mL of 10 M HCl must be used to create 100 mL of a 5 M solution.
Lesson 17 Conservation of Momentum grade 9 I want the answer.
Answer:
1) 1.5 kg
2) 0.6 kg
Explanation:
[tex](3)(30) = 60m, m = 90/60 = 1.5[/tex] kg
[tex](0.8)(15) = 20m, m = 12/20 = 0.6[/tex] kg
A hot metal plate at 150°C has been placed in air at room temperature. Which event would most likely take place
over the next few minutes?
O Molecules in both the metal and the surrounding air will start moving at lower speeds.
O Molecules in both the metal and the surrounding air will start moving at higher speeds.
O The air molecules that are surrounding the metal will slow down, and the molecules in the metal will speed up.
O The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Answer: The event air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down would most likely take place over the next few minutes.
Explanation:
A process in which heat is evolved is called an exothermic process.
When hot metal plate at [tex]150^{o}C[/tex] is placed in air at room temperature then heat is given off by the metal plate due to which there will occur a decrease in kinetic energy of its molecules.
As a result, molecules in the metal will slow down.
Whereas heat is absorbed by the air molecules from the metal due to which kinetic energy of air molecules will increase.
Thus, we can conclude that the event air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down would most likely take place over the next few minutes.
A 24.0 gram sample of copper was
ncated from 25.0°C to 500.0°C 43783
of heat were absorbed, what is the
Specific_heat of copper?
Answer:
3.84 J/g°C
Explanation:
Using the formula as follows:
Q = m × c × ∆T
Where;
Q = amount of heat (J)
m = mass of substance
c = specific heat of copper
∆T = change in temperature (°C).
Based on the provided information;
Q = 43783J
m = 24g
∆T = 500°C - 25°C = 475°C
c = ?
Using Q = m × c × ∆T
43783 = 24 × c × 475
43783 = 11400c
c = 43783 ÷ 11400
c = 3.84 J/g°C
have some points chemistry gang RISE UP
Answer:
I WILL ACHIEVE GREATNESS
Explanation:
Answer:
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Explanation:
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Scientists clarify an element based on what criteria
A)Atomic number
B)Mass number
C)Atomic mass
D)Atomic symbol
the mass in g of 3 moles Al .
Answer:
81 gm
Explanation:
The mass of 1 mole is 27 g
So, Mass of 3 moles of Aluminium would be 3 × 27 = 81 gm..Thus mass of 3 Moles of Aluminium is 81 gm.
The enthalpy of solution of NaCl in water is about 3.88 kJ/mol. However, the solubility of NaCl in water is relatively high. Which statement about the entropy of the solution process explains why NaCl dissolves in water even though the process is endothermic?
a. the entropy increases when NaCl dissolves in water
b. the entropy remains the same when NaCl dissolves in water
c. the entropy decreases when NaCl dissolves in water
d. entropy has nothing to do with the solution process
We have that the statement that explains why NaCl dissolves in water even though the process is endothermic the given as,
The entropy increases when NaCl dissolves in water.Option A
HeatGenerally ,Sodium chloride is crystalline salt, when its dissolved is H20 , it dissociates its ion, the ions are scattered through out the solution which results in increased in randomness .
Therefore, the entropy increases when NaCl dissolves in water,
Option A
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What volume of solution is needed to prepare a 0.50M solution of sodium hydroxide using 2.0 g of solute? Show your work
Answer:
0.10 L
Explanation:
First we convert the 2.0 grams of solute (meaning sodium hydroxide) into moles, using its molar mass:
2.0 g ÷ 40 g/mol = 0.05 mol NaOHThen we can calculate the required volume of solution, using the definition of molarity:
Molarity = moles / litersliters = moles / molarity0.05 mol / 0.50 M = 0.10 LAtomic number: 19 is what Chemical symbol?
Answer:
oficialismo hemostasia Jalisco
Answer:
K
Explanation:
Potassium is atomic no 19 and it is k because is from kalium, the Meldiaeval Latin for potash, which may have derived from an arabic word quality, meaning alkali.
Atomic mass, 39.098amu
Oxidation status, +1
Year discovered, 1807
Melting point, 63.28 degrees Celsius(145.90degrees Fahrenheit )
Boiling point, 760 degrees Celsius (1400 degrees Fahrenheit )
How did oxygen first enter Earth's atmosphere?
A. Meteorite impacts
B. Breakdown of Precambrian rocks
C. Biological processes
D. Volcanic outgassing
Answer:
I think c biological processes
A lab technician adds 3.50 mL of a 0.00450 M stock solution of barium chloride to a test tube, then adds other solutions so that the total volume is 10.00 mL.
In the absence of reactions, the molarity of barium ions is ______ M in the solution and the molarity of chloride ions is ______ M in solution.
IMPORTANT: Report each answer to 3 significant figures, I made this as a free response fill-in question and the question will be graded credit/no credit. For example, 0.0000123 or 1.23. Do NOT include units as they are already provided for you.
Answer:
[Ba²⁺] = 1.58 × 10⁻³ M
[Cl⁻] = 3.16 × 10⁻³ M.
Explanation:
Step 1: Calculate the molar concentration of BaCl₂
We have 3.50 mL (V₁) of a 0.00450 M (C₁) BaCl₂ solution and we dilute it to a final volume of 10.00 mL (V₂). We can calculate the final concentration of BaCl₂ by using the dilution rule.
C₁ × V₁ = C₂ × V₂
C₂ = C₁ × V₁ / V₂
C₂ = 0.00450 M × 3.50 mL / 10.00 mL = 1.58 × 10⁻³ M
Step 2: Calculate the molar concentrations of the Ba²⁺ and Cl⁻ ions
Let's consider the dissociation of BaCl₂.
BaCl₂(aq) ⇒ Ba²⁺(aq) + 2 Cl⁻(aq)
The molar ratio of BaCl₂ to Ba²⁺ is 1:1. The molar concentration of Ba²⁺ is 1/1 × 1.58 × 10⁻³ M = 1.58 × 10⁻³ M.
The molar ratio of BaCl₂ to Cl⁻ is 1:2. The molar concentration of Cl⁻ is 2/1 × 1.58 × 10⁻³ M = 3.16 × 10⁻³ M.
0.350 moles of H2O is equivalent to (blank amount) molecules of water.
Answer:
is has around 1/5 lyrics of water
Answer:
[tex]1 \: mole \: = \: 6.02 \times {10}^{23} \: molecules \\ 0.350 \: moles \: = \: (0.350 \times 6.02 \times {10}^{23} ) \: molecules \\ = 2.107 \times {10}^{23} \: molecules[/tex]
A silver bar with a specific heat of 0.235J/gºC has a mass of 250.g and is heated from 22.0°C to 68.5°C. How much heat will the silver bar absorb?
Answer:
2731.875 J
Explanation:
Applying
Q = cm(t₂-t₁)................ Equation 1
Where Q = amount of heat, c = specific heat capacity of silver, m = mass of silver, t₂ = Final temperature of silver, t₁ = Initial temperature of silver
From the question,
Given: c = 0.235 J/g°C, m = 250 g, t₁ = 22.0°C, t₂ = 68.5°C
Substitute these values into equation 1
Q = 0.235×250(68.5-22.0)
Q = 58.75(46.5)
Q = 2731.875 J
If a drop of red dye is placed in the middle of a shallow dish of water, the dye will diffuse slowly and a red cloud of dye will grow larger with time.
a. True
b. False
Answer:
True
Explanation:
Diffusion is the movement of the particles of a substances from a region of higher concentration to a region of lower concentration.
Diffusion occurs in response to a concentration gradient.
In this case, the dye is at a higher concentration at the middle of the shallow dish of water. Diffusion causes the dye to spread out gradually thereby causing the red cloud to grow larger with time.
Chemical bond stretching frequencies depend on two major factors, namely atomic weight and bond stiffness. The frequency absorbed is directly proportional to the bond strength (stiffness) but inversely proportional to the atomic weight. Which of the following bonds will give the highest absorption frequency value?
A. C single bond C.
B. C double bond C.
C. All would be the same frequency.
D. C triple bond C.
Answer:
D. C triple bond C.
Explanation:
The absorption frequency value is highest for carbon-carbon triple bond. The stretching frequencies are much higher than the bending frequency. It mainly depends upon the strength of the bonds as well as masses of the bonded atoms.
The triple bonds have higher stretching strength than the double bonds and double bonds have higher strength than single carbon to carbon bonds.
The triple bonds has a higher bond order, i.e. 3. So it has maximum stretching bonds.
The question is listed in the image attached.