Answer:
a. Rate constant: 1.2118x10⁻⁴ yrs⁻¹
b. The age of the object is 20750 years
Explanation:
a. We can solve the rate constant in an isotope decay by using Half-Life, as follows:
K = Ln 2 / Half-life
K = ln 2 / 5720 years =
1.2118x10⁻⁴ yrs⁻¹b. The general equation of isotope decay is:
Ln [A] = -kt + Ln [A]₀
Where [A] is concentration of the isotope after time t,
k is rate constant
and [A]₀ initial concentration of the isotope.
Computing the values of the problem:
Ln [0.89x10⁻¹⁴] = -1.2118x10⁻⁴ yrs⁻¹t + Ln [1.1x10⁻¹³]
-2.5144 = -1.2118x10⁻⁴ yrs⁻¹t
20750 years = t
The age of the object is 20750 years
how many grams is 26.17 L Xe at STP
Answer:
Mass = 157.56 g
Explanation:
Given data:
Mass of Xe in gram = ?
Volume = 26.17 L
Temperature = standard = 273.15 K
Pressure = standard = 1 atm
Solution:
we will calculate the number of moles first.
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
1 atm ×26.17 L = n×0.0821 atm.L/ mol.K × 273.15 K
26.17 atm.L = n× 22.43 atm.L/ mol
n = 26.17 atm.L / 22.43 atm.L/ mol
n = 1.2 mol
Mass of Xe:
Mass = number of moles × molar mass
Mass = 1.2 mol × 131.3 g/mol
Mass = 157.56 g
Why must energy be absorbed to change a liquid to a gas?
Answer: Heat energy is absorbed to vaporize a liquid because molecules which are held together by intermolecular forces in the liquid are separated as the gas is formed
Explanation:whatever that means^ I looked it up
A mixture of krypton and argon gas is expanded from a volume of 88.0L to a volume of 100.0L, while the pressure is held constant at 27.0atm. Calculate the work done on the gas mixture. Round your answer to 3 significant digits, and be sure it has the correct sign (positive or negative).
Answer:
-3.28 × 10⁴ J
Explanation:
Step 1: Given data
Pressure exerted (P): 27.0 atmInitial volume (Vi): 88.0 LFinal volume (Vf): 100.0 LStep 2: Calculate the work (w) done by the gaseous mixture
We will use the following expression.
w = -P × ΔV = -P × (Vf - Vi)
w = -27.0 atm × (100.0 L - 88.0 L)
w = -324 atm.L
Step 3: Convert w to Joule (SI unit)
We will use the conversion factor 1 atm.L = 101.325 J.
-324 atm.L × 101.325 J/1 atm.L = -3.28 × 10⁴ J
Why does a mixture of hydrogen and oxygen in a balloon not spontaneously explode at room temperature
Answer:
Because the molecules of the mixture would be compact or bond together at room temperature. In this case, both gases will condense to form water (or ice, if the room temperature is prolonged) and such droplets of water will not cause a balloon to spontaneously explode at room temperature.
Explanation:
A mixture of hydrogen and oxygen will form water. Recall that the chemical formula for water is H₂O, where H represents Hydrogen and O represents Oxygen.
A balloon is a light (not thick) solid substance with a thin membrane when blown or filled with some elements or gases.
Room Temperature means cool or cold temperature. You already know that generally at room temperature, the molecules of any substance will stick together or will become less mobile (less spontaneous).
In this case, hydrogen gas and oxygen gas will go through a process called condensation - to form water - and then through the process called freezing - to form ice.
At room temperature, the gases will first change state (state of matter) from gaseous to liquid and then from liquid to solid.
This is why the balloon will NOT spontaneously explode.
Can you click the picture
Answer:
B.
Explanation:
Answer:
no but it might just be my computer acting up again
Explanation:
According to VSEPR theory, if there are three electron domains in the valence shell of an atom, they will be arranged in a(n) __________ geometry.A. linearB. trigonal planarC. octahedralD. trigonal bipyramidalE. tetrahedral
Answer: B. trigonal planar
Explanation:
Valence Shell Electron Pair Repulsion Theory (VSEPR) is a model to predict the geometry of the atoms making up a molecule where atoms are arranged such that the forces of repulsion are minimum.
If a central atom is bound to three electron domains ,the number of electron pairs is 3, that means the hybridization will be [tex]sp^2[/tex] and the electronic geometry of the molecule will be trigonal planar as the electron pairs will repel each other and attain a position which is most stable.
Example: [tex]BCl_3[/tex] with 3 electron domains has trigonal planar geometry.
Question:
A coefficient is a number listed before a compound or atom, telling how many of the compounds are needed so that the Law of Conservation of Mass is obeyed. Given the information provided, how many iron atoms are there?
4 Fe2S3
Answers:
A.) 4
B.) 12
C.) 8
D.) 2
Answer: I think it’s 4
Explanation:
strength, sickness, Stretchiness, and color are all different
1:Traits
2:Futures
3:None of the above
Answer:
1) Traits
Explanation:
Strength, sickness, Stretchiness, and color are all different because they result in a different body part and there all traits of the body
2.5 moles O2
Determine the mass (grams)
Answer:
80g
Explanation:
Given parameters:
Number of moles of O₂ = 2.5moles
Unknown:
Mass of O₂ = ?
Solution:
To solve this problem, we use the expression below
Mass = number of moles x molar mass
Molar mass of O₂ = 2(16) = 32g/mol
So;
Mass = 2.5 x 32 = 80g
If you start with 8.95 g of crude sulfanilamide and recrystallize it from ethanol to recover 7.20 g of pure sulfanilamide, what is the percent recovery
Answer:
[tex]\% rec=80.4\%[/tex]
Explanation:
Hello!
In this case, since the percent recovery for this crystallization operation is computed as shown below:
[tex]\% rec=\frac{m_{recovered}}{m_{initial}} *100\%[/tex]
Thus, by plugging in the initial 8.95 g and the recovered 7.20 g, we obtain:
[tex]\% rec=\frac{7.20g}{8.95g} *100\%\\\\\% rec=80.4\%[/tex]
Best regards!
A chemist adds of a M sodium nitrate solution to a reaction flask. Calculate the millimoles of sodium nitrate the chemist has added to
The given question is incomplete. The complete question is:
A chemist adds 35.0 mL of a 2.82M sodium nitrate (NaNO3) solution to a reaction flask. Calculate the millimoles of sodium nitrate the chemist has added to the reaction flask.
Answer: 98.7 mmol
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
[tex]Molarity=\frac{n}{V_s}[/tex]
where,
n = milli moles of solute
[tex]V_s[/tex] = volume of solution in ml
Now put all the given values in the formula of molarity, we get
[tex]2.82=\frac{n}{35.0}[/tex]
[tex]n=2.82\times 35.0=98.7mmol[/tex]
Therefore, the millimoles of sodium nitrate the chemist has added to reaction flask are 98.7
What does a key on a weather map tell you?
Answer:
It tells what kind of weather. depending on what color it will show the amount of precipitation. for example, a light green will mean it is raining lightly. a blue means that it is snowing
Explanation:
Match each titration term with its definition.
A. When the required amount of one solution has been added to the second solution to complete the reaction.
B. Process of slowly adding a solution to react with another solution and determine the concentration of one of the solutions based on the reaction between them.
C. A reagent added to the analyte solution that changes color when the reaction is complete.
D. Solution of known concentration that is slowly added to a solution of unknown concentration.
E. Solution of an unknown concentration that has another solution slowly added to it.
F. Glassware that allows a solution to be precisely and slowly added to another solution
a. Indicator
b. Equivalence point
c. Titration
d. Burette
e. Titrant
f. Analyte
Answer: Please see answers in explanation column
Explanation:
A. When the required amount of one solution has been added to the second solution to complete the reaction------- Equivalence point
B. Process of slowly adding a solution to react with another solution and determine the concentration of one of the solutions based on the reaction between them.---- Titration
C. A reagent added to the analyte solution that changes color when the reaction is complete.----- Indicator
D. Solution of known concentration that is slowly added to a solution of unknown concentration------Titrant
E. Solution of an unknown concentration that has another solution slowly added to it.------Analyte
F. Glassware that allows a solution to be precisely and slowly added to another solution--------- Burette
Titration is the process that is used in quantitative analytical Chemistry to determine the concentration of an analyte ( Unknown concentration). This is done by slowly passing the Titrant ( Known concentration) from the burette into a conical flask containing the analyte after which an indicator must have been added to the analyte solution such that when the equivalence point is reached, the analyte changes colour to show that the reaction has been completed.
A mixture of 620 lbmol/h of 36 mol% benzene and the remainder toluene is separated continuously into two products. One product is 98 mol% benzene and the other is 95 mol% toluene. Calculate the flow rates of both products in kmol/h.
Answer:
[tex]P_1=206.7lbmol/h\\\\P_2=413.3lbmol/h[/tex]
Explanation:
Hello!
In this case, for the separation of the benzene-toluene mixture, we can use the following mole balances including the given mole fraction at each stream per species:
[tex]B:0.36*620=0.98P_1+0.05P_2\\\\T:0.64*620=0.02P_1+0.95P_2[/tex]
That can be solved by using a solver for P1 (benzene-rich flow) and P2 (toluene-rich flow):
[tex]P_1=206.7lbmol/h\\\\P_2=413.3lbmol/h[/tex]
Best regards!
Question 1
1 pts
What does pH stand for?
Power of hydrogen
Potential of hydroxide
O Power of hydroxide
O Purple House
Answer:
potential of hydroxide
Explanation:
What is the molar mass of Ca(CIO4)2? (3 points)
239.0 g/mol
Answer:
239.0 g/mol
Explanation:
Ca molar mass = 40.078
Cl molar mass = 35.45
O molar mass = 16
so that makes the total equation: 40.078+2(35.45)+8(16)
that equals 238.978 which rounds to 239.0 g/mol
What is the short name used to refer to the elements that make up livings?. Single choice.
A. LIVE
B. CHNOPS
C. PBNJ
Answer:
B
Explanation:
Answer:
B. CHNOPS
Explanation:
Carbon Dioxide
Hydrogen
Nitrogen
Oxygen
Phosphorus
Sulfur
Consider the Bohr Model of Phosphorus below. Which statement is FALSE?
(A) The electrostatic potential energy of ALL electrons is negative.
(B) The electrons with the least potential energy are closest to the nucleus.
(C) Energy is released when the electron is ejected from the atom.
(D) When an electron is infinitely far from the nucleus, the electrostatic potential energy is O.
Answer:
(C) Energy is released when the electron is ejected from the atom.
Explanation:
In the Bohr model of the atom, electrons are arranged in energy levels. The electrons in the lowest energy levels are nearest to the nucleus. An electron may move from a lower to a higher energy level by absorbing energy that is equal to the difference between the energies of the higher and lower energy level.
The potential energy of all electrons inside the atom have negative values and an electron which is infinitely far from the nucleus has an electrostatic potential energy of zero.
Energy is absorbed when an electron is removed from the atom (ionization). Hence the process is highly endothermic. Therefore it is false to say that "Energy is released when the electron is ejected from the atom."
Write and by the appropriate atoms and draw a dipole moment vector for any of the following molecules that are polar: (a) HF (b) IBr (c) Br2 (d) F2
Answer:
See explanation and image attached
Explanation:
A molecule is said to have a dipole moment whenever there is a separation of charge in the molecule. When this occurs, one end of the molecule is positive while the other end is negative. The molecule is now said to be polar.
If two atoms in a molecule have a significant difference in electronegativity between them, then the bond between the both atoms is polar and will possess a dipole moment.
The direction of the dipole moment vector is always towards the negative atom as shown in the image attached. Only HF and IBr are polar. Diatomic molecules such as Br2 and F2 are nonpolar.
The dipole moment refers to the separation of charges in the molecule. Atoms are in opposite directions. (a) HF. F is more electronegative. The vector is pointing F. (b) IBr. The vector points Br.
------------------------------
The dipole moment can be used to analyze the molecule's polarity.
Let us say that a molecule is composed of an element with a positive charge (E1 ⁺) and another element with a negative charge (E2⁻). These two elements are separated by a distance d.
E1 ⁺ --------- (d) ----------- E2⁻
(+Q) (-Q)
Each element has a charge magnitude, Q. Depending on the charge, Q can be either positive (+Q) or negative (-Q).
When +Q = -Q, the dipole moment is represented with a μ letter, and it equals the product between the magnitude of the charge, Q, and the distance, d.
μ = Q x d
Now, let us analyze the molecule estructure.
The covalent bond that joins two atoms is composed of two electrons.
If one of the atoms is more electronegative, it pulls the electrons to its side.
This is represented with an arrow carrying a positive symbol, +→ . The arrow is directed to the position of the electronegative atom.
The highest density of electrons surrounding one of the atoms is represented as δ⁻, while the lowest density of electrons is represented as δ⁺.
In these situations, in which charges are different, and there is a separation of charge in the molecule, we can say that molecules are polarized.
These molecules have a dipole moment, and when representing them, the direction of the dipole moment arrow is always pointing to the most negative atom.
In the attached files you will find the molecules
---------------------------------
You can learn more about dipole moment at
https://brainly.com/question/16260427
What is the purpose of stirring a solution while it is being heated? Select one: To slow down any reactions that occur in the solution To encourage sudden boiling in the solution To prevent the solute from dissolving into solution To help evenly distribute heat throughout the solution
Answer:
To help evenly distribute heat throughout the solution
Explanation:
The purpose of stirring a solution while being heated would be to evenly distribute heat throughout the solution.
When a vessel containing a solution is heated, the molecules at the lower portion of the vessel get heated first before heat graduate radiates around the entire solution. Stirring the solution will ensure that the process of heat distribution around the entire solution is quickened.
Stirring a solution while heating does not slow down the reactions that might occur in the solution, does not encourage sudden boiling of the solution, and neither does it prevent solute from dissolving into the solution.
How many grams of H2O will be formed when 36.8 g H2 is mixed with 40.2 g O2 and allowed to completely react to form water
Answer:
45.225 grams of H₂O will be formed when 36.8 g H₂ is mixed with 40.2 g O₂
Explanation:
The balanced reaction is:
2 H₂ + O₂ → 2 H₂O
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:
H₂: 2 molesO₂: 1 moleH₂O: 2 molesBeing the molar mass of the compounds:
H₂: 2 g/moleO₂: 32 g/moleH₂O: 18 g/molethen, by reaction stoichiometry, the following amounts of reactant and product mass participate:
H₂: 2 moles* 2 g/mole= 4 gO₂: 1 mole* 32 g/mole= 32 gH₂O: 2 moles* 18 g/mole= 36 gThe limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.
To determine the limiting reagent, it is possible to use the reaction stoichiometry of the reaction and a simple rule of three as follows: if by stoichiometry 4 g of H₂ react with 32 g of O₂, 36.8 g of H₂ with how much mass of O₂ will it react?
[tex]mass of O_{2} =\frac{36.8 grams of H_{2}*32 grams of O_{2} }{4 grams of H_{2}}[/tex]
mass of O₂=294.4 grams
But 294.4 grams of O₂ are not available, 40.2 grams are available. Since you have less mass than you need to react with 36.8 grams of H₂, oxygen O₂ will be the limiting reagent.
Then you can apply the following rule of three: if by stoichiometry 32 grams of O₂ form 36 grams of H₂O, 40.2 grams of O₂ how much mass of H₂O will it form?
[tex]mass of H_{2}O=\frac{40.2 grams of O_{2} *36 grams of H_{2}O }{32 grams of O_{2} }[/tex]
mass of H₂O= 45.225 grams
45.225 grams of H₂O will be formed when 36.8 g H₂ is mixed with 40.2 g O₂
Similar figures have the same ______ but different ______.
a
measure; shapes
b
sizes; shapes
c
shape; sizes
d
value; measures
Answer:
c shapes and sizes
Explanation:
I just finished my test on it
3. Why are nutrients needed for living things? Describe the difference between living and nonliving things.
PLEASE HELP!
ITS INTEGRATED SCIENCE
Answer:
-4
16:00
8
it's pretty accurate besides it's way of numbering.
Lucy volunteers at an animal shelter, and she takes care of an orange
tabby cat and her kittens. Some of the kittens have orange markings,
while others have gray markings. What units of genetic material
determine how living things look?
Answer: variations
Explanation:
A mixture of 2 g of H2 gas (MM= 2g/mol) and 16 g of Ne gas (MM= 4g/mol) were occupied in 2 L balloon
at 30'C. What is the total pressure
inside the balloon?
The total pressure inside the balloon : 62.1 atm
Further explanationGiven
2 g of H2 gas (MM= 2g/mol)
16 g of Ne gas (MM= 4g/mol)
2 L balloon at 30'C
Required
The total pressure
Solution
mol H2 :
= mass : MM
= 2 : 2
= 1
mol Ne :
= 16 : 4
= 4
Total mol of gas = 5
T = 30+273 = 303 K
Ideal gas law :
P = nRT/V
P = 5 moles x 0.082 L.atm/mol.K x 303 K / 2 L
P = 62.1 atm
The arrangement in which the X substituents are at maximum separation is called the anti conformation. What is the dihedral angle between the X substituents for the anti conformation
Answer:
The dihedral angle between the X substituents for the anti conformation is 180°
Explanation:
Note: I think this question is not complete. Still, it can be answered. But for your concept and understanding, I am completing this question and then I will try to solve this question for you.
Other part of this question is about Gauche conformations and angle between the x substituents.
So, I will be drawing and answering both.
Answer to the original question: 180°
So, the dihedral angle between the X substituents for the anti conformation is 180°
Answer to the Gauche Conformation: 60°
Here, in this question we are discussing about the possible different staggered conformations of CH2XCH2X
You can see the angles between the X substitutes in anti conformations and Gauche Conformations for yourself in the attachment below.
Furthermore, this CH2XCH2X has 3 possible different staggered conformations. Out of which, one is anti conformation and other two are Gauche conformations.
Please refer to the attachment to see the conformations. Check the angles between X-X. In anti conformation, angle between X-X is 180° and energy is lower, because of the less interaction between H and X. However, in Gauche conformation, angle between X-X is 60° and energy is higher, because of the more interactions between H and X than anti conformation.
g What is the mass ratio for CaCl2 if a sample analyzed to be 36.1 grams calcium and 63.9 grams chlorine
Answer:
[tex]0.361Ca\\\\ 0.639Cl[/tex]
Explanation:
Hello!
In this case, since the mass ratio here can be computed as:
[tex]\frac{mass\ Ca}{mass\ CaCl_2} \\\\\frac{mass\ Cl}{mass\ CaCl_2}[/tex]
For each element forming the compound we obtain:
[tex]\frac{36.1g}{63.9g+36.1g} = 0.361Ca\\\\\frac{63.9g}{63.9g+36.1g} = 0.639Cl[/tex]
Best regards!
How many atoms are in 1.00 mol of calcium
Answer: 6.02214076 atoms Ca
Explanation:
Ca is monoatomic, so atoms in 1 mol = avogadro number
Do you think it's possible for someone to completely eliminate procrastination from their life? Why or why not
Answer:
No and Yes
Explanation:
This is both possible and impossible. When you put your mind to what you believe, you can achieve it through patience and minded values. Your mind can either be your Greatest enemy or your Best Ally.
