Answer:
α-iron (BCC) has faster diffusion rate because of lower values in activation energy and pre-exponential value.
Explanation:
Taking each parameters or data at a time, we can determine the values/a constant for each parameters in the diffusion coefficient equation.
For α-iron (BCC), the diffusion coefficient = pre-exponential value,Ao × e^( -Activation energy,AE)/gas constant,R × Temperature.
Converting the given Temperature, that is 900°C to Kelvin which is equals to 1173.15K.
For α-iron (BCC), the pre-exponential value, Ao = 1.1 × 10^-6, and the activation energy, AE = 87400.
Thus, we have that the diffusion coefficient = 1.1 × 10^-6 × e(-87400)/1173.15 × 8.31.
Diffusion coefficient for α-iron (BCC) = 1.41 × 10^-10 m^2/s.
Also, For the γ-iron (FCC), the pre-exponential value, Ao = 2.3 × 10^-5 and the activation energy, AE = 148,00.
From these values we can see that both the exponential value, Ao and the activation energy for γ-iron (FCC) are higher than that of α-iron (BCC).
Thus, the diffusion coefficient for the γ-iron (FCC) = 2.3 × 10^-5 × e ^-(14800)/8.31 × 1173.15.
Then, the diffusion coefficient for the γ-iron (FCC) = 5.87 × 10^-12 m2/s.
Therefore, there will be faster diffusion in α-iron (BCC) because of lower activation energy and vice versa.
The radius of Pt atom in an fcc structure is 0.1386 nm. Pt has atomic mass of 195.09 g/mol. Calculate the density of this fcc structure. The Avogadro’s number NAis 6.022 x 1023 per mole
Answer:
21.51g/cm³
Explanation:
To answer this question we need to know that, in 1 unit FCC cell:
Edge length = √8 * R
Volume = 8√8 * R³
And there are 4 atoms per unit cell
The mass of the 4 atoms of the cell, in grams, is:
4 atom * (1mol / 6.022x10²³atom) * (195.09g / mol) = 1.2958x10⁻²¹g
Volume in cm³:
0.1386nm * (1x10⁻⁷cm / 1nm) = 1.386x10⁻⁸cm
Volume = 8√8 * (1.386x10⁻⁸cm)³
Volume = 6.02455x10⁻²³cm³
And density, the ratio of mass and volume, is:
1.2958x10⁻²¹g / 6.02455x10⁻²³cm³ =
21.51g/cm³
What is the volume of 11.2 g of O2 at 7.78 atm and 415 K?
Answer:
1.53 L
Explanation:
Step 1: Given data
Mass of oxygen (m): 11.2 gPressure (P): 7.78 atmTemperature (T): 415 KIdeal gas constant (R): 0.0821 atm.L/mol.KStep 2: Calculate the moles (n) corresponding to 11.2 g of oxygen
The molar mass of oxygen is 32.00 g/mol.
11.2 g × (1 mol/32.00 g) = 0.350 mol
Step 3: Calculate the volume of oxygen
We will use the ideal gas equation.
P × V = n × R × T
V = n × R × T / P
V = 0.350 mol × (0.0821 atm.L/mol.K) × 415 K / 7.78 atm
V = 1.53 L
If the density of aluminum is 2.7g/ml, what is the volume of 12.0g?
Answer:
The answer is 4.44 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\ [/tex]
From the question we have
[tex]volume = \frac{12}{2.7} \\ = 4.4444444....[/tex]
We have the final answer as
4.44 mLHope this helps you
A student asks why the ashes from a fire have a much lower mass than the wood that was burned.
Which is the correct answer to the student’s question?
Gases are released into the air.
Atoms in the wood are destroyed.
Heat causes the molecules to change color.
Water inside the wood solidifies.
(I am not in college)
magnesium: atomic number
Answer:
Magnesiums atomic number is 12
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The prefix for one-millionth is micro-.
True
False
"Calculate the pH of an aqueous solution at 25°C that is (a) 0.15 M in HCl. 0.82 (b) 3.7 M in HNO3. -0.57 (c) 6.9 × 10−4 M in HClO4."
Answer:
See explanation
Explanation:
The pH of a solution is defined as the negative logarithm of hydrogen ion concentration.
For HCl
pH= - log[0.15] = 0.82
For HNO3
pH= -log[3.7] = -0.57
For HClO4
pH= - log [6.9 × 10^-4] = 3.16
plsss help!!!!! I'll give u brainlest and 10 points
Answer:
I would say it is true
Explanation:
When you cook food in a hot pan , which statement is correct? Energy from the food is transferred to the pan or energy from the food is transferred to the food.
Answer:
Not to sure! I think energy from the pan is transferred to the food? Maybe.
Explanation:
Calculate the following quantity: molarity of a solution prepared by diluting 49.16 mL of 0.0270 M ammonium sulfate to 525.00 mL.
Answer:
2.528x10⁻³M
Explanation:
Molarity is an unit of concentration used in chemistry. Is defined as the moles of solute per liter of solution.
To find the molarity of the solution we need to determine the moles of ammonium sulfate present in the initial 49.16mL solution and, with total volume, we can find the molarity, thus:
Moles ammonium sulfate:
49.16mL = 0.04916L * (0.0270 moles / L) =
1.327x10⁻³moles ammonium sulfate
These moles are present in 525.0mL = 0.525L. Thus, molarity of the solution will be:
1.327x10⁻³moles ammonium sulfate / 0.525L =
2.528x10⁻³MTo vaporize/condense a substance, does the substance have to absorb or release heat?
Answer: it would release heat because the thermal energy it absorbed to become a gas. so it would release heat. hope this helps :)
Explanation:
____ KClO3 = ____ KCl + ____ O2
Answer:
2KCIO3=2KCI+3O2
Explanation:
1. equalize right side O with left side O- Right side we have 3 and left only 2 so we add 3 in front(on left side)(3*2=6 O on both sides)
2.we add 2 on right side so now we have 6 O on left and 6 O on right and 2KCI
3.Add 2 on right side KCI so on both sides we got 2 KCI
How many liters of chlorine gas at 25°C and 0.950 atm can be produced by the reaction of 12.0 g of MnO2 with excess HCl(aq) according to the following chemical equation?
MnO2(s) + 4HCl(aq) → MnCl2(aq) + 2H2O(l) + Cl2(g)
Answer:
3.55 L.
Explanation:
We'll begin by calculating the number of mole in 12 g of MnO2. This can be obtained as follow:
Molar mass of MnO2 = 55 + (16×2)
= 55 + 32
= 87 g/mol
Mass of MnO2 = 12 g
Mole of MnO2 =...?
Mole = mass /Molar mass
Mole of MnO2 = 12 / 87
Mole of MnO2 = 0.138 mole
Next, we shall determine the number of mole Cl2 produced from the reaction. This is illustrated below:
The balanced equation for the reaction is given below:
MnO2(s) + 4HCl(aq) → MnCl2(aq) + 2H2O(l) + Cl2(g)
From the balanced equation above,
1 mole of MnO2 reacted to produce 1 mole of Cl2.
Therefore, 0.138 mole of MnO2 will also produce 0.138 mole of Cl2.
Finally, we shall determine the volume of Cl2 gas obtained from the reaction. This can be obtained as shown below:
Temperature (T) = 25 °C = 25 °C + 273 = 298 K
Pressure (P) = 0.950 atm
Number of mole (n) = 0.138 mole
Gas constant (R) = 0.0821 atm.L/Kmol
Volume (V) =.?
PV = nRT
0.950 × V = 0.138 × 0.0821 × 298
Divide both side by 0.950
V = (0.138 × 0.0821 × 298) / 0.950
V = 3.55 L
Therefore, 3.55 L of chlorine gas were obtained from reaction.
PLEASE PLEAS HELP Which of the following compounds is insoluble in water?
a) ZnSO4
b) K2SO4
c) Na2CO3
d) Ag2CO3
Answer:
Your answer is d
Explanation: silver carbonate Ag2CO3 is insoluble in water
Level 1 01 Which correctly pairs the outside particles with their charge? A. Electrons: Positive B. Protons: Positive C. Neutrons: Neutral D. Electrons: Negative
Answer:
D. Electrons: Negative.
Explanation:
Hello, happy to help you today!
In this case, by considering the Bohr's atomic model in which atom is composed by a nuclei containing both protons and neutrons which are positively and neutrally charged respectively and surrounding electrons assembled in orbits or levels of energy which are negatively charged in order to provide a balance to the atom, the correct statement is: D. Electrons: Negative. Also consider the Bohr's model on the attached picture.
My best regards to you!
________ and ________ fibres are obtained from animals
Answer:
Explanation:
Silk and wool
Answer:
silk and wool fibers are obtained from animals
Explanation:
good luck :)
What type of structural isomerism is shown by [Cr(NH3)4Cl2]Br and
[Cr(NH3)4ClBr]Cl?
Explanation:
Ionisation isomerism is shown by [Cr(NH₃)₄Cl₂]Br and [Cr(NH₃)₄ClBr]Cl
4. This is low wet land.
A. swamp
B. island
C. desert
D. peninsula
5. Japan is one of these.
A. island
B. peninsula
C. swamp
D. desert
Answer:
swap
Explanation: because it is a low wet land
Answer:
4. swamp
5. Island
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a compound has a molecular formular of C12H24O6.What is the compound's empirical formula
Answer:
The empirical formula for C12 H24 O6 is C2 H4 O.
Answer:
We are given the formula of the compound:
C12H24O6
The empirical formula of a molecular formula is the lowest whole number ratio between the number of atoms of each element
The ratio of C to H to O in the given formula is :
12 : 24 : 6
we notice that all 3 of the numbers have 6 in common. Dividing all three of the numbers by 6, we get:
2 : 4 : 1
Hence, the ratio of Carbon to Hydrogen to Oxygen in the empirical formula of the given compound is 2 : 4 : 1 ,
Empirical Formula = C2H4O
What is another term for the limbic system?:
A. primitive brain
B. logical brain
C. gender center
D. memory center
Answer:
a
Explanation:
because the sytem it si locate at the bothe side
2. What is the purpose of subscripts?
3. What is the difference between monatomic and polyatomic ions?
4. How do the names of monatomic anions end?
5. When are Roman numerals used in cation names ?
2. Chemical formulas are used to describe the types of atoms and their numbers in an element or compound. The atoms of each element are represented by one or two different letters. When more than one atom of a specific element is found in a molecule, a subscript is used to indicate this in the chemical formula.
3. The main difference between monatomic and polyatomic ions is that monatomic ions are composed of single atoms whereas polyatomic ions are composed of two or more atoms per ion.
4. These are nonmetal elements which have accepted extra electrons. These ions are relatively few in number and are listed below. Monatomic anions are named by taking the root of the element name and applying an -ide ending. Other important simple anions.
5. This is indicated by assigning a Roman numeral after the metal. The Roman numeral denotes the charge and the oxidation state of the transition metal ion. For example, iron can form two common ions, Fe2+ and Fe3+. To distinguish the difference, Fe2+ would be named iron (II) and Fe3+ would be named iron (III).
What is the correct 1 letter code for the amino acid sequence Glutamic Acid-Histadine-Tyrosine Select one: a. E-H-Y b. G-H-T c. Q-H-T d. E-H-T
Answer:
a. E-H-Y
Explanation:
A group of three nucleotides is called a codon that codes for a specific amino acid in the protein. There are 20 essential amino acids present in human body and are required in the diet.
Each amino acid is given a one-letter code that makes the study of amino acid sequences easy. One letter code for the given amino acid sequence Glutamic Acid-Histidine-Tyrosine is E-H-Y in which E is code for Glutamic Acid, H is a code for Histidine, and Y is a code for Tyrosine.
Hence, the correct answer is "a. E-H-Y".
Given the following equation:
4 NH_3(g) + 5 O_2(g) → 4 NO(g) + 6 H_2O(l)
How many grams of H_2O is produced if 66.60 grams of NO is produced?
Use the periodic table to identify the chemical symbol or name for each element below.
zirconium:
zr
rhenium:
re
: As
: K
tin:
yttrium:
: Yb
Answer:
zirconium is Zr
rhenium is Re
As is arsenic
K is potassium
tin is Sn
yttrium is Y
ytterbium is Yb
Explanation:
With the help of the periodic table, the identification of the chemical symbol or name for each element is represented as follows:
Zirconium: Zr. Rhenium: Re. Arsenic: As.Potassium: K.Tin: Sn. Yttrium: Y. Ytterbium: Yb. What are the chemical elements?Chemical elements may be defined as any type of substance that cannot be further decomposed into simpler substances through the utilization of other ordinary chemical processes or external factors. These elements possess specific physical as well as chemical properties distinctly.
In the modern periodic table, each element is arranged on the basis of its increasing atomic number. Each element possesses its unique symbol, atomic mass, and physical properties like boiling points, melting points, density, etc.
Therefore, with the help of the periodic table, the identification of the chemical symbol or name for each element is well represented above.
To learn more about the Periodic table, refer to the link:
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A liquid has a volume of 62.7 mL and a density of 2.59 g/mL. What is its mass? (show all work)
Answer:
162.4
Explanation:
The formula for mass is density* volume so 62.7 multiplied by 2.59 equals 162.393. then you round so your anwser would be 162.4
Which statement best demonstrates how data from a global positioning system (GPS) can be used to lessen the effects of a
wildfire? (1 point)
GPS data can be used by people to quickly evacuate an area because of a wildfire
GPS data can be used by scientists to predict weather patterns that can lead to a wildfire
GPS data can be used by firefighters to identify the boundaries of a wildfire
GPS data can be used by first responders to calculate the safest route to a wildfire
Answer: here is your answer
Explanation: You are visiting your Grandmother and notice that she is eating a balanced diet, taking vitamins, getting the proper amount of sleep and is not overweight. Despite her healthy lifestyle, she appears run down and tired. You realize that it's due to her lack of physical activity. Write a convincing letter to your grandma explaining the benefits of participating in regular physical activity.
State Hess' law of constant heat summation.
(b) Calculate the enthalpy of formation of CH4 from the following data:
i) C(s) + O2(g) → CO2(g); ∆H = -393.7 kJ/mol
ii) H2(g) + 1⁄2 O2(g) → H2O(l); ∆H = -285.8 kJ/mol
iii) CH4(g) + 2 O2(g)→ CO2(g) + 2H2O(l); ∆H = -890.4 kJ/mol
Answer:
-74.6 kj/mol
Explanation:
you can see the answer at the pic
Calculate the mass of arsenic trihydride produced from 117.4 g of hydrogen gas with excess arsenic trioxide:
Answer: The mass of [tex]AsH_3[/tex] produced is, 1528.8 grams.
Explanation : Given,
Mass of [tex]H_2[/tex] = 117.4 g
Molar mass of [tex]H_2[/tex] = 2 g/mol
First we have to calculate the moles of [tex]H_2[/tex].
[tex]\text{Moles of }H_2=\frac{\text{Given mass }H_2}{\text{Molar mass }H_2}[/tex]
[tex]\text{Moles of }H_2=\frac{117.4g}{2g/mol}=58.7mol[/tex]
Now we have to calculate the moles of [tex]AsH_3[/tex]
The balanced chemical equation is:
[tex]6H_2+As_2O_3\rightarrow 2AsH_3+3H_2O[/tex]
From the reaction, we conclude that
As, 6 moles of [tex]H_2[/tex] react to give 2 moles of [tex]AsH_3[/tex]
So, 58.7 moles of [tex]H_2[/tex] react to give [tex]\frac{2}{6}\times 58.7=19.6[/tex] mole of [tex]AsH_3[/tex]
Now we have to calculate the mass of [tex]AsH_3[/tex]
[tex]\text{ Mass of }AsH_3=\text{ Moles of }AsH_3\times \text{ Molar mass of }AsH_3[/tex]
Molar mass of [tex]AsH_3[/tex] = 78 g/mole
[tex]\text{ Mass of }AsH_3=(19.6moles)\times (78g/mole)=1528.8g[/tex]
Therefore, the mass of [tex]AsH_3[/tex] produced is, 1528.8 grams.
How many grams of Cl are in 31.2g CF2Cl2
Answer:
Mass = 42.6 g
Explanation:
Given data:
Mass of CF₂Cl₂ = 31.2 g
Mass of Cl₂ = ?
Solution:
Number of moles of CF₂Cl₂ = mass/molar mass
Number of moles = 31.2 g/121 gmol
Number of moles = 0.3 mol
1 mole of CF₂Cl₂ contain 2 moles of Cl atom.
0.3 mol × 2 = 0.6 mol
Mass of Cl₂:
Mass = number of moles × molar mass
Mass = 0.6 mol × 71 g/mol
Mass = 42.6 g
The reaction between HCl and KOH results in an increase in temperature in the solution. Select the correct statement from the list below.
a) this is an endothermic reaction
b) this is a phase change reaction
c) this is a vaporization reaction
d) this is an exothermic reaction
Answer:
d) this is an exothermic reaction.
Explanation:
The reaction between HCl and KOH results in an increase in temperature in the solution. Select the correct statement from the list below.
a) this is an endothermic reaction . NO. This would cause a decrease in the temperature of the solution.
b) this is a phase change reaction . NO. All the species remain in the aqueous phase.
c) this is a vaporization reaction . NO. All the species remain in the aqueous phase.
d) this is an exothermic reaction. YES. The reaction releases heat, so it is exothermic.