Answer:
266Lr
Thirteen isotopes of lawrencium are currently known; the most stable is 266Lr with a half-life of 11 hours, but the shorter-lived 260Lr (half-life 2.7 minutes) is most commonly used in chemistry because it can be produced on a larger scale.
Explanation:
hopefully that helps you
What is the reason behind an atom being neutral?
You may have to recrystallize any or all of the components of your extraction mixture, benzoic acid, ethyl-4-aminobenzoate and fluorenone, depending on their purity after isolation. You should have the recystallization solvents in your protocol. They are respectively:
Answer:
the Recrystallization solvents are;
-Sodium Hydroxide Base (NaOH)
- Hydrochloric Acid (HCl)
- Sand bath when acidic and basic components are removed.
Explanation:
Recrystallization is simply a technique used to purify an impure compound in a solvent.
Now, we want to purify the mixture of benzoic acid, Ethyl-4-aminobenzoate and fluorenone.
For the benzoic acid, it can be separated out of the mixture by addition of sodium hydroxide base (NaOH).
The Ethyl - 4 - aminobenzoate will be separated from the mixture by the addition of Hydrochloric Acid (HCl).
The fluorenone would be separated out by heating the mixture in a sand bath after the basic and acidic components have already been extracted out.
Thus, the Recrystallization solvents are;
-Sodium Hydroxide Base (NaOH)
- Hydrochloric Acid (HCl)
- Sand bath when acidic and basic components are removed.
(6 points) Calculate the maximum number of moles and grams of H2S that can form when 158 g of aluminum sulfide reacts with 131 g of water: Show work for full poi
Answer:107.1 g, 124.1 g
Explanation:
The equation of the reaction is;
Al2S3(s) + 6H20(l) ----> 2Al(OH)3(s) + 3H2S(g)
Hence;
For Al2S3
Number of moles= reacting mass/molar mass
Number of moles = 158g/150gmol-1 =1.05 moles
If 1 mole of Al2S3 yields 3 moles of H2S
1.05 moles of Al2S will yield
1.05 × 3/1 = 3.15 moles
Mass of H2S = 3.15moles × 34 gmol-1 = 107.1 g
For water
Number of moles of water = 131g/18gmol-1= 7.3 moles
6 moles of water yields 3 moles of H2S
7.3 moles of water will yield 7.3 × 3/6 = 3.65 moles of H2S
3.65 moles × 34 gmol-1 =124.1 g
Give Me An Atom With The Following Characteristics Lanthanide series
Plz can someone help FAST
How does a circuit with a 1.5-volt battery compare to a circuit with a 9-volt battery?
the density of an 18.0 solution of ammonium sulfate is 1.10g/ml. What mass of Ammonium sulfate is required to prepare 275ml of this solution
Answer:
Therefore, 54.45 g of Ammonium sulphate is required
Explanation:
Molar mass of ammonium sulphate, (NH₄)₂SO₄ = 132 g/mol
Since density of solution is 1.10 g/ml, a 1 mL solution has mass = 1.10 g
275 mL solution will have a mass = 275 * 1.10 = 302.5 g
Since the solution is 18% ammonium sulphate by weight,
mass of ammonium sulphate present in 275 mL solution = 302.5 * 18/100
mass of ammonium sulphate present in 275 mL solution = 54.45 g
Therefore, 54.45 g of Ammonium sulphate is required
Suppose you are studying the kinetics of the iodine-catalyzed decomposition of hydrogen peroxide. 2 H 2 O 2 ⟶ 2 H 2 O + O 2 If you determine the initial rate is 7.50 × 10 − 4 M/s when [ H 2 O 2 ] = 0.546 M and [ K I ] = 0.212 M , what is the rate constant? Assume that the order of both reactants is 1.
Answer:
[tex]k=6.48x10^{-3}M^{-1}s^{-1}[/tex]
Explanation:
Hello.
In this case, based on the given information, we can write the rate law as shown below:
[tex]r=k[H_2O_2][KI][/tex]
Since the overall order of reaction is 2 being 1 for reach reactant. Thus, by knowing the initial rate and concentrations, the rate constant turns out:
[tex]k=\frac{r}{[H_2O_2][KI]}=\frac{7.50x10^{-4}M/s}{0.546M*0.212M}\\ \\k=6.48x10^{-3}M^{-1}s^{-1}[/tex]
Best regards!
The rate constant, k is [tex]6.48x10^{-3}M^{-1}s^{-1}[/tex]
Rate law:The rate law should be
[tex]r = k[H_2O_2]{KI}[/tex]
Since the total order of the reaction is 2 being 1 for reach reactant. So, by knowing the beginning rate and concentrations, the rate constant turns out:
[tex]k = \frac{r}{k[H_2O_2]{KI}} = \frac{7.50x10^{-4}M/s}{0.546M\times 0.212M}[/tex]
k = [tex]6.48x10^{-3}M^{-1}s^{-1}[/tex]
Learn more about reactants here; https://brainly.com/question/21029530
A baseball strikes the roof of a car and dents it. The paint on the roof begins to crack and chip, exposing the metal. The exposed metal on the roof rusts, eventually causing a small hole in the roof. 17. Which event is a chemical change? The baseball strikes the roof The roof of the car dents The paint cracks and chips The exposed metal rusts
Answer:
The exposed metal rusts is an example of a chemical change because rust is an example of a chemical change in objects for example bicycles, scooters, etc.
What is a chelating agent?
Answer:
Chelation is a type of bonding of ions and molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate ligand and a single central atom. These ligands are called chelants, chelators, chelating agents, or sequestering agents.
Answer:
Chemical compound that react with metal ions. They can form several covalent bonds to a metal without changing its own structure.
Explanation:
There's a list of chelating agents you can find in your book probably. An application of chelating agents is to transport metal ions across the membranes.
you should also know:
Chelating agents are any compound that reacts with a metal ion to produce a metal ion.
Ligand ion molecule or functional group that binds to another chemical to make a larger complex.
They are used to detoxify poisonous metal agents by binding and converting them so the body can excrete them without further harm.
Why are noble gases nonreactive?
A
Their melting points are too high to react.
B
They have 8 valence electrons making them inert, so they do not react.
C
They have 8 valence electrons, making them too dense to react.
D
They have 18 valence electrons, making them over expanded, so they cannot react.
Answer:
B
Explanation:
Answer:
B
Explanation:
Select the term that matches each definition:
a) A decrease in the solubility of an ionic compound as a result of the addition of a common ion.
b) The mass of a salt in grams that will dissolve in 100 mL of water.
c) A solution that has dissolved the maximum amount of a compound at a given temperature. Any further addition of salt will remain undissolved.
d) The product of the molarities of the dissolved ions, raised to a power equal to the ion's coefficient in the balanced chemical equation.
e) The maximum number of moles of a salt that will dissolve in 1 L of solution.
*** Answer options for all questions: ***
- Solubility
- Molar Solubility
- Solubility product constant
- Common ion effect
- Saturated Solution
Answer: a) A decrease in the solubility of an ionic compound as a result of the addition of a common ion : Common ion effect
b) The mass of a salt in grams that will dissolve in 100 mL of water: Solubility
c) A solution that has dissolved the maximum amount of a compound at a given temperature. Any further addition of salt will remain undissolved: Saturated solution
d) The product of the molarities of the dissolved ions, raised to a power equal to the ion's coefficient in the balanced chemical equation : Solubility product constant
e) The maximum number of moles of a salt that will dissolve in 1 L of solution : Molar solubility
Explanation:
Solubility is expressed usually as the mass of solute per 100 grams or 100 ml of solvent.
Molar solubility of a solid is expressed as the concentration of the dissolved solid in a saturated solution.
Solubility product constant is defined as the equilibrium constant in which a solid ionic compound is dissolved to produce its ions in solution. It is represented as [tex]K_{sp}[/tex]
The common-ion effect is the decrease in solubility of a sparingly soluble salt by the addition to the solution of a soluble compound with an ion in common with the precipitate.
Saturated solution is defined as the solution in which no more solute particles can be dissolved in the solvent.
How many 20 mL extractions of organic solvent are needed to extract at least 99.5% of 50.0 g Compound A from 100 mL of water if K
Answer:
5 extractions to extract at least 99.5% of 50.0 g Compound A from 100 mL of water
Explanation:
If K=10...
Partition coefficient is defined as the ratio of concentrations of a compound A in two inmiscibles solvents:
K = 10 = Conc. Organic solvent / Conc. Water
Usually organic phase over aqueous phase.
In the first 20mL extraction, the organic solvent will extract:
10 = X / 20mL / (50.0g - X) / 100mL
10 = 100X / (1000-20X)
10000 - 200X = 100X
10000 = 300X
X = 33.3g of compound A are extracted in the first extraction
Remember you want to extract 99.5%, that is 50.0g*99.5% = 49.75g
In the aqueous phase remain: 50-33.3g = 16.7g:
Second extraction:
10 = X / 20mL / (16.7g - X) / 100mL
10 = 100X / (334-20X)
3340 - 200X = 100X
3340 = 300X
11.1g are extracted and will remain: 16.7g - 11.1g = 5.6g
Third extraction:
10 = X / 20mL / (5.6g - X) / 100mL
10 = 100X / (112-20X)
1120 - 200X = 100X
1120 = 300X
3.8g are extracted and will remain: 5.6g - 3.8g = 1.8g
Fourth extraction:
10 = X / 20mL / (1.8g - X) / 100mL
10 = 100X / (36-20X)
360 - 200X = 100X
360 = 300X
1.2g are extracted and will remain: 1.8g -1.2g = 0.6g
Fifth extraction:
10 = X / 20mL / (0.6g - X) / 100mL
10 = 100X / (12-20X)
120 - 200X = 100X
120 = 300X
0.4g are extracted. The total extractions gives:
33.3g + 11.1g + 3.8g + 1.2g + 0.4g = 49.8g
That means, you need to do:
5 extractions to extract at least 99.5% of 50.0 g Compound A from 100 mL of waterPLZ HELP ME...
Graceful, and yet majestic, it clings to the land like a thing that has taken root. Beautiful as a vision of fairyland it salutes our sight. The impression it makes upon the visitor is one of astonishment, an astonishment that grows with every visit. No one who has been upon it can ever forget it. This great structure cannot be confined to the limits of local pride. The glory of it belongs to the race. Not one shall see it and not feel prouder to be a man.
Which of the following is the best objective summary of the excerpt?
The Brooklyn Bridge is an unforgettable sight!
The glory of the bridge belongs to the human race.
The grandeur of the bridge would make people feel proud.
Visitors of New York should be astonished by the bridge.Is a compound considered a pure substance? Why or why not?
BTW im on edguinity
Answer:
its b
Explanation:
its b sorry if im wrong but mine said b
Answer:
B.
Explanation: I got it right on edg
What is the gravitational potential energy, in joules, of a 75 kg person that is 1000.0
meter above the ground? Gravitational acceleration = 9.81 m/s2
Answer:
In this example, a 3 kilogram mass, at a height of 5 meters, while acted on by Earth's gravity would have 147.15 Joules of potential energy, PE = 3kg * 9.81 m/s 2 * 5m = 147.15 J. 9.81 meters per second squared (or more accurately 9.80665 m/s 2 ) is widely accepted among scientists as a working average value for Earth's gravitational pull.
Explanation:
Which option BEST explains how thermal equilibrium interacts with heat transfer between particles?
a
Thermal equilibrium stops the transfer of energy in just one direction when both objects reach the same temperature, but allows their particles to continue transferring that energy back and forth.
b
Thermal equilibrium always transfers energy from the hotter object to the colder one, and increases the energy and speed of moving particles in both objects as the temperature decreases.
c
Thermal equilibrium helps the transfer of energy between the particles of some materials better than others, but always stops the transfer of energy in materials like plastic and wood.
d
Thermal equilibrium quickly transfers energy back to the particles of the object that was originally hotter, and requires that the particles in both objects have reached equal energy and density.
Answer:
Thermal equilibrium stops the transfer of energy in just one direction when both objects reach the same temperature, but allows their particles to continue transferring that energy back and forth.
Explanation:
a. The transfer of energy occurs until both objects reach thermal equilibrium. But particles are always moving and crashing with each other. TRUE.
b. The heat transfer occurs from the hotter object to the colder one but moving of particles descreases with temperature decreasing. FALSE.
c. Plastic and wood have a poor quality to transfer energy but there is no material that "stops" perfectly the transfer of energy. FALSE.
d. The heat is transferred from the particles of the hotter object to the particles of the colder one. FALSE
a water sample is found to have a cl- content of 100ppm as nacl what is the concentration of chloride in moles per liter
Answer:
The concentration of chloride ion is [tex]2.82\times10^{-3}\;mol/L[/tex]
Explanation:
We know that 1 ppm is equal to 1 mg/L.
So, the [tex]Cl^-[/tex] content 100 ppm suggests the presence of 100 mg of [tex]Cl^-[/tex] in 1 L of solution.
The molar mass of [tex]Cl^-[/tex] is equal to the molar mass of Cl atom as the mass of the excess electron in [tex]Cl^-[/tex] is negligible as compared to the mass of Cl atom.
So, the molar mass of [tex]Cl^-[/tex] is 35.453 g/mol.
Number of moles = (Mass)/(Molar mass)
Hence, the number of moles (N) of [tex]Cl^-[/tex] present in 100 mg (0.100 g) of [tex]Cl^-[/tex] is calculated as shown below:
[tex]N=\frac{0.100\;g}{35.453\;g/mol}=2.82\times 10^{-3}\;mol[/tex]
So, there is [tex]2.82\times10^{-3}\;mol[/tex] of [tex]Cl^-[/tex] present in 1 L of solution.
Move the chemistry book down again so it's surface touches the physics book. Quickly move the chemistry book back and forth. What's different when motion is faster?
Answer:
The temperature of the physics book increases as the chemistry book slides across it.
Explanation:
from plato
The temperature of the physics book increasing as the chemistry book slides across it is the difference when motion is faster.
What is Temperature?This is defined as the degree of hotness or coldness of a body and it increases when there is more friction.
When motion is faster , there is an increase in friction and increase in thermal(heat) energy which leads to increase in temperature.
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Stephen learned that there are two forces that keep the moon in orbit around Earth. How do these forces keep the moon from flying off into space?
A. Gravity keeps the moon in motion, and inertia attracts the moon toward Earth.
B. Gravity attracts the moon toward Earth, and inertia keeps the moon in motion.
C. Gravity attracts the moon toward Earth, and the distance keeps it from going further away.
D. Mass weighs the moon down so it stays close to Earth, and inertia keeps the moon in motion.
Answer:
b
Explanation:
Answer:
Gravity attracts the moon Earth, and Inertia keeps the moon in motion.
Explanation:
1. Determine the electron-domain geometry and molecular geometry for each of the following.
a. SBr2
b. PI4+
c. IBr2−
2. The following three compounds all have the same general formula, XF4. Compare the electron-domain geometries of these three compounds and explain what characteristic(s) of the central atom causes differences in geometry.
a. SiF4:
b. SeF4:
c. XeF4:
Answer:
SBr2: Electron geometry-tetrahedral; molecular geometry-trigonal pyramidal
PI4+: Electron geometry-tetrahedral; molecular geometry-tetrahedral
IBr2−: Electron geometry- Trigonal bipyramidal ; molecular geometry- linear
Explanation:
In SBr2, the molecule is of the structure type AX2E2 hence it is based on a tetrahedron but have two lone pairs of electrons hence the molecular geometry is trigonal pyramidal.
PI4+ has four electron domains and all of them are bond pairs hence both electron geometry and molecular geometry are both tetrahedral.
IBr2- is of the structure type AX2E3 hence it is based on a trigonal bipyramd and has a linear molecular geometry.
2)
SiF4 has a tetrahedral molecular and electron domain geometry because the central atom(Si) has no lone pairs.
SeF4 has a trigonal bipyramidal electron geometry with the structure AX4E. Its molecular geometry is See-saw since it has one lone pair of electrons that causes a deviation from its ideal trigonal bypyramidal geometry.
XeF4 has an octahedral electron domain geometry and the molecule is AX4E2. The two lone pairs are positioned above and below the plane of a square hence the molecule is square planar.
How might ocean waves affect a beach over thousands of years? Explain your answer.
Answer:
Explanation:
Well a oceans waves could erode the beach it it is a rocky one, it can wash the sand out and can cause rocks to fall.
Question 11
4 pts
Using the formula 2H202 --> 2H2O + O2, if 7.30 moles of peroxide are
decomposed, how many moles of oxygen will be formed?
Answer:
3.65 mol O₂
Explanation:
Step 1: RxN
2H₂O₂ → 2H₂O + O₂
Step 2: Define
Given - 7.30 mol H₂O₂
Solve - x mol O₂
Step 3: Stoichiometry
[tex]7.30 \hspace{3} mol \hspace{3} H_2O_2(\frac{1 \hspace{3} mol \hspace{3} O_2}{2 \hspace{3} mol \hspace{3} H_2O_2} )[/tex] = 3.65 mol O₂
Hydrogen has 3 isotopes. Hydrogen 1, Hydrogen 2 and Hydrogen 3. What is the difference between these 3 is isotopes
Answer:
Number of neutrons
Explanation:
All have one single proton. Hydrogen has no neutrons. Hydrogen 2 or deuterium has 1 neutron. Hydrogen 3 or tritium has 2 neutrons.
Calculate the mass in 0.523 moles of Ag?
Answer:
56.41 g
Explanation:
Moles = Mass ÷ [tex]A_{r}[/tex]
Given that,
moles = 0.523 mol
[tex]A_{r}[/tex] = 107.8682 u
mass = ?
Mass = Moles × [tex]A_{r}[/tex]
Mass = 0.523 × 107.8682
mass = 56.41 g
What kind of metal is Cu?
Transition metal
Alkaline earth metal
Alkali metal
Answer: Transition metal
Explanation: Copper is definitely a transition metal because the Cu2+ ion has an incomplete d level.
Phosphoric acid, which is commonly used as rust inhibitor, food additive and etching agent for dental and orthopedic use, can be synthesized using a two-step thermal process. In the first step, phosphorus and oxygen react to form diphosphorus pentoxide:
P4(l)+ 5O2(g) → P2O5()
In the second step, diphosphorus pentoxide and water react to form phosphoric acid:
P2O5(g)+ 3H2O → 2H3PO4
Write the net chemical equation for the production of phosphoric acid from phosphorus, oxygen and water. Be sure your equation is balanced.
Answer:
P4(l) + 5O2(g) + 6H2O(l) → 4H3PO4(aq)
Explanation:
Step 1
P4(l)+ 5O2(g) → 2P2O5()
Step 2
2P2O5(g)+ 6H2O(l) → 4H3PO4(aq)
Overall balanced equation;
P4(l) + 5O2(g) + 6H2O(l) → 4H3PO4(aq)
Notice carefully that the correct coefficients were used to balance the equations and obtain the accurate overall reaction equation. All the steps involved were shown above. Reactants that occur on both sides cancel out and do not appear in the final equation.
Based on the visible cell structures, which of the following statements is true?
All of the cells are plant cells.
All of the cells have chloroplasts.
All of the cells are animal cells.
All of the cells have a nucleus.
The incredible catalytic power of enzymes can perhaps best be appreciated by imagining how challenging life would be without just one of the thousands of enzymes in the human body. For example, consider life without fructose-1,6-bisphosphatase, an enzyme in the gluconeogenesis pathway in liver and kidneys, which helps produce new glucose from the food we eat:
Fructose-1,6-bisphosphate + H2O → Fructose-6-phosphate + Pi
The human brain requires glucose as its only energy source, and the typical brain consumes about 120. g (or 480. calories) of glucose daily. Ordinarily, two pieces of sausage pizza could provide more than enough potential glucose to feed the brain for a day. According to a national fast-food chain, two pieces of sausage pizza provide 1260 calories, 49.0 % of which is from fat. Fats cannot be converted to glucose in gluconeogenesis, so that leaves 615 calories potentially available for glucose synthesis. The first-order rate constant for the hydrolysis of fructose-1,6-bisphosphate in the absence of enzyme is 2.00×10-20 sec-1.Calculate how long it would take to provide enough glucose for one day of brain activity from two pleces of sausage pizza without the enzyme.
Answer:
t = 7.58 * 10¹⁹ seconds
Explanation:
First order rate constant is given as,
k = (2.303 /t) log [A₀] /[Aₙ]
where [A₀] is the initial concentraion of the reactant; [Aₙ] is the concentration of the reactant at time, t
[A₀] = 615 calories;
[Aₙ] = 615 - 480 = 135 calories
k = 2.00 * 10⁻²⁰ sec⁻¹
substituting the values in the equation of the rate constant;
2.00 * 10⁻²⁰ sec⁻¹ = (2.303/t) log (615/135)
(2.00 * 10⁻²⁰ sec⁻¹) / log (615/135) = (2.303/t)
t = 2.303 / 3.037 * 10⁻²⁰
t = 7.58 * 10¹⁹ seconds
The density for potassium is 0.856 g/cm3. What would be the mass of a 35 cm3 piece of potassium?
Answer:
30 grams
Explanation:
density = mass / volume => mass = density x volume
mass = 0.856 g/cm³ x 35 cm³ = 29.96 grams ≅ 30 grams 2 sig. figs.
Compute the values of the diffusion coefficients for the interdiffusion of carbon in both α-iron (BCC) and γ-iron (FCC) at 900°C. Which is larger? Explain why this is the case.
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.
SpongeBob noticed that his favorite pants were not as clean as they used to be and wonders how can he get them clean again? His friend Sandy told him that he should try using Clean-O detergent, a new brand of laundry soap she found at Sail-Mart. SpongeBob made sure to wash one pair of pants in plain water and another pair in water with the Clean-O detergent. After washing both pairs of pants a total of three times, the pants washed in the Clean-O detergent did not appear to be any cleaner than the pants washed in plain water.
1)What is SpongeBob’s question?
2)What is SpongeBob’s claim?
3)What is the independent variable?
4)What is the dependent variable?
Answer:
1) SpongeBob’s question is that "what would be the appropriate way to wash his favorite pants as they don't seem as clean as earlier"?
2) SpongeBob’s claim that Clean-O detergent is unable to wash the pants more cleaner as compared to plain water.
3) Independent variable in the given example is the quantity of Clean-O detergent and plain water as it can be changed or manipulated.
4) Dependent variable in the given example is the cleanliness of pants as it will be affected by the quantity of Clean-O detergent and plain water which is an independent variable.