Answer:
Chromosome condensation, the landmark event at the onset of prophase, often begins in isolated patches of chromatin at the nuclear periphery. Later, chromosome condense into two threads termed sister chromatids that are closely paired along their entire lengths.
Explanation:
hope dis help & may I have brainly plz
which of the following is indicated by the ph value of a solution?
a- it's hydrogen ion concentration
b- its ammonium ion concentration
c- ability to undergo chemical reaction
d- its ratio of solute amount to solvent volume
Answer:
c- ability to undergo chemical reaction
What is the molarity of an HCl solution if 25.0 mL of this solution required 17.80 mL of 0.108 M NaOH to reach the end point in a titration?
Answer:
[tex]\boxed {\boxed {\sf 0.0769 \ M}}[/tex]
Explanation:
We are asked to find the molarity of an acid given the details of a titration experiment. The formula for titration is as follows:
[tex]M_AV_A= M_B V_B[/tex]
In this formula, M is the molarity of the acid or base and V is the volume of the acid or base. The molarity of the hydrochloric acid (HCl) is unknown and the volume is 25.0 milliliters.
[tex]M_A * 25.0 \ mL = M_BV_B[/tex]
The molarity of the sodium hydroxide (NaOH) is 0.108 molar and the volume is 17.80 milliliters.
[tex]M_A * 25.0 \ mL = 0.108 \ M * 17.80 \ mL[/tex]
We are solving for the molarity of the acid and we must isolate the variable [tex]M_A[/tex]. It is being multiplied by 25.0 milliliters. The inverse operation of multiplication is division, so we divide both sides of the equation by 25.0 mL.
[tex]\frac {M_A * 25.0 \ mL }{25.0 \ mL}= \frac{0.108 \ M * 17.80 \ mL }{25.0 \ mL}[/tex]
[tex]M_A= \frac{0.108 \ M * 17.80 \ mL }{25.0 \ mL}[/tex]
The units of milliliters cancel.
[tex]M_A= \frac{0.108 \ M * 17.80 }{25.0 }[/tex]
[tex]M_A= \frac{1.9224}{25.0 } \ M[/tex]
[tex]M_A= 0.076896 \ M[/tex]
The original measurements have 3 and 4 significant figures. We must round our answer to the least number of sig figs, which is 3. For the number we calculated, that is the ten-thousandth place. The 9 to the right of this place tells us to round the 8 up to a 9.
[tex]M_A \approx 0.0769 \ M[/tex]
The molarity of the hydrochloric acid is 0.0769 Molar.
If you have a polyatomic anion of Ammonium (NH41+), how many valence electrons must your Lewis Structure have?
Answer:
One can draw the 3-dimensional structure of an atom once they have the Lewis Structure of an atom. The 3-dimensional geometrical structure of ammonium, NH4+ is referred to as Tetrahedral. ... But the + sign decrees that NH4+ has 8 valence shell electrons, due to the positive ion.
Explanation:
The element europium exists in nature as two isotopes: has a mass of u and has a mass of u. The average atomic mass of europium is u. Calculate the relative abundance of the two europium isotopes.
Answer:
Problem Details
The element europium exists in nature as two isotopes: 151Eu has a mass of 150.9196 amu, and 153Eu has a mass of 152.9209 amu. The average atomic mass of europium is 151.96 amu. Calculate the relative abundance of the two europium isotopes.
answer:
151Eu = 48%, 153Eu = 52%
Which is the best interpretation of the two flat portions of the graph?
In those portions, the heat supplied to the substance by the heater does not lead to a temperature rise as intermolecular forces are broken.
When a substance is heated, we normally expect that its temperature will rise as a consequence.
However, heat may be supplied to a substance but its temperature does not rise owing to the fact that the heat energy supplied is used to break intermolecular bonds.
This occurs during fusion and boiling. The heat supplied at these point does not result in temperature rise since it is used to break intermolecular bonds. The temperature remains steady during these processes as shown by the two flat portions on the graph in the image attached to the question. This heat supplied is known as the latent heat.
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Answer:
The answer for me was "These show where changes of state are occuring"
Explanation:
I got it right
instruments that have been soaking in cold sterilization for blank minutes are considered aseptic and can be used during non sterile procedures
a. 60
b. 30
c. 15
d. 10
Answer:
Its C you can check
Cho các quá trình và số liệu sau:
C(d,s) ⭢ C (g,s) (1) : ΔH0298 = - 1,9 kJ
ΔG0298 = - 2,87 kJ
C(g,s) + O2 (k) ⭢ CO2 (k) (2): ΔH0298 = - 393,5 kJ
a)Giải thích tại sao trạng thái chuẩn của C lại là C(g) mà không phải là C (d).
b)Tính ΔH0298 của phản ứng sau:
C(d,s) + O2 (k) ⭢ CO2 (k) (3)
ΔH0298 của phản ứng 3 có phải là ΔH0298, sinh nhiệt của CO2 không ? Tại sao?
Answer:
rrgggf in the world of the world of the world of the up the good morning I will take a user and pass it on the
A bio catalyst that increases the rate of the reaction without being changed
a) Aluminum oxide. b) Silicon dioxide. c) Enzyme. d) Hydrogen peroxide
43. What is the
than the reaction substrate.
42. A
Explanation:
Enzymes are proteins functioning as catalysts that speed up reactions by lowering the activation energy. A simple and succinct definition of an enzyme is that it is a biological catalyst that accelerates a chemical reaction without altering its equilibrium.
A reaction has a rate constant of 0.0492 sec-1; how long will it take (in minutes) until 0.433 mol/L of the compound is left, if there was 0.656 mol/L at the start
Answer:
λ(Decay constant) = 0.0492sec-¹
The relationship between Decay Constant and Half life (t½)
λ=0.693/t½
given the decay constant as 0.0492
We can get the Half life
t½ = 0.693/0.0492
t½= 14.09secs.
N = N°(½)ⁿ
Where N= Remaining Amount of the original Compound
N° = Original Amount of compound.
n is simply a tern used to represent the ratio of time taken/half life
In other words
n=t/t½
Given N°=0.656 mol/L
N=0.433mol/L
0.433 = 0.656(½)ⁿ
(½)ⁿ = 0.433/0.656
(½)ⁿ = 0.660
Taking the Natural Log(Ln) of both sides
Ln(½)ⁿ = Ln(0.66)
nLn(½) = -0.4155
n(-0.6931) = -0.4155
n= 0.4155/0.6931
n= 0.5995.
n = time/half life
t = half life x n
t = 14.09 x 0.5995
t = 8.45secs.
H2+O=???????????????????
Answer:
H₂O
Explanation:
Two molecules of Hydrogen and one molecules of Oxygen, when mixed, create H₂O, or water. There is no scientific name for H₂O due to it's common name. It is just refereed to as "water" or H₂O.
If you dissolve 0.1 mol of formic acid in 1 L of water, ther esulting solution contains 0.004 mol of H₃O+. Based on this information, is formic acid a strong acid, or is it a weak acid?
Please explain!
In an ideal case, the acid would completely protonate. such an acid would be a strong acid. Dissociation of Formic acid looks like:
HCOOH + H₂O → COOH⁻ + H₃O⁺
one mole of formic acid should give one mole of Hydronium(H₃O⁺) ions
similarly, 0.1 moles of formic acid should produce 0.1 moles of hydronium ions. but we know that it is not the case, a much lesser amount is actually formed.
Which means that Formic acid did not completely dissociate into COOH⁻ and H⁺ ions.
Hence, Formic Acid is a weak acid
We know
Any acid
Containing carbon is weak Containing no carbon is strongFormic acid stands for HCOOH
It contains C means dissociation is less .
The dissociation of H+ is less means acidity is less.
Weak acidHELP ASAS 15 POINTS
When using the process of evaporation to separate a mixture, what is left behind in the evaporating dish?
A. None of these.
B. The liquid evaporates and the solid is left in the dish.
C. The mixture does not separate, and the entire mixture evaporates.
D. The mixture does not separate, and the entire mixture remains in the dish.
Answer:
liquid will be evaporated while solid remains
The average bond order is the number of bonds between two atoms taking into account resonance.
a. Draw a Lewis structure for the nitrite ion and answer the questions below.
1. there are equivalent Lewis structures for NO2-.
2. the average N-O bond order is .
b. Draw a Lewis structure for sulfur dioxide and answer the questions below.
1. there are equivalent Lewis structures for SO2.
2. the average S-O bond order is _______.
1. Sulfur dioxide, or SO2 , has two resonance structures which contribute equally to the overall hybrid structure of the molecule. However, a third Lewis structure can be drawn for SO2 which is more stable in theory, but doesn't quite match experimental data.
2.
[tex] \color{red} = \frac{No. \: of \: bonding \: electron \: pairs}{No. \: of \: bonded \: atoms} [/tex]
[tex]In \: each \: resonance \: contributor, \\ there \: are \: six \: bonding \: electron \\ pairs \: and \: four \: atoms \: bonded \\ to \: the \: SS \: atom. \: Thus,[/tex]
[tex]BO = \frac{6}{4} = 1.5
[/tex]
A base which can be used to relieve indigestion
Explanation:
Antacids are medications used to manage the symptoms of indigestion and heartburn. Antacids contain active ingredients that are bases. These allow antacids to neutralize any stomach acid which could be causing digestive discomfort.
what is ethylene oxcide used for?
soaking of instruments
steam autoclave
cold sterilization
gas autoclave
Answer:
Ethylene oxide, also known as C2H4O, is commonly used for sterilizing things, particularly medical equipment. Cold sterilization is a form of sterilization, so, "cold sterilization" is correct.
Let me know if this helps!
Answer: Ethylene oxcide is used for cold sterilization
Explanation:
What type of bonding is occuring in the compound below?
A. Covalent polar
B. Metallic
C. Ionic
D. Covalent nonpolar
Answer:
(B). it's metallic bonding
Stibnite, Sb2S3, is a dark gray mineral from which antimony metal is obtained. What is the mass percent of antimony in the sulfide? If you have 1.00 kg of an ore that contains 10.6% antimony, what mass of Sb2S3 (in grams) is in the ore?
Answer:
duw8 Wert gsi
Explanation:
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The mass percent of antimony in the sulfide is 71.7% and the mass of Sb2S3 is 0.148 g.
What is mass percent?Mass percent is defined as a way of expressing a concentration or describing a component in a particular mixture.
To calculate the mass percent of an element in a compound, divide the mass of the element in 1 mole of the compound by the molar mass of the compound and multiply the result by 100.
Mass percent = Mass of chemical / Total mass of compound x 100
Mass of ore = 10 kg
% antimony in ore = 10.6%
= 10.6 / 100 = 0.106 g
Mass of antimony = 0.106 g
Mass percent = Mass of antimony / Mass of stibnite x 100
71.7% = 0.106 / X x 100
X = 0.106 x 1000 / 71.7 x 1000
= 106 / 717 = 0.148 g
Thus, the mass percent of antimony in the sulfide is 71.7% and the mass of Sb2S3 is 0.148 g.
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What is an example of an extensive property
What would be the name of this compound?
Answer:
2,3 Dimethyl hexane
Explanation:
First, start the count from which side is given the CH3 smallest number
first; the longest carbon chain in this compound is 6
and you don't have any double and triple bonds or functional groups so it is Hexane
you start to count from the right side to give the branch molecules the smallest number ..
CH3 = methyl
and you have 2 methyl in this compound ..
and 2 mean you must write ( Di )
you write the name in this way
2,3 Dimethyl hexane
hope this helps you.
stay safe ...
Where do reactions in a solid generally take place?
A. At the center of the solid.
B. All throughout the solid
C. Only on opposite sides of the solid due to repelling forces.
D. On the surface of the solid.
Answer:
It's D. On the surface of the solid.
Explanation:
If the reactant is a solid, the surface area of the solid will impact how fast the reaction goes. This is because the two types of molecule can only bump into each other at the liquid solid interface, i.e. on the surface of the solid. So the larger the surface area of the solid, the faster the reaction will be.
Amphiphilic molecule: ___________
a. have both oxidizing and reducing groups.
b. are micelles.
c. have chromophores in two different wavelength regions.
d. have both acidic and basic groups.
e. have both hydrophilic and hydrophobic groups.
Gluconolactone is a(n) _________________________, classified as a(n) _______________, that cyclizes to produce a(n) ___________________. C-1 oxidized derivative of glucose Ester of gluconic acid Aldonic acid
Answer:
gravity
Explanation:
How long do spent fuel rods remain dangerously radioactive?
Answers
A.
The rods are no longer radioactive because the radioisotopes are used up.
B.
Spent fuel rods remain radioactive for several years after the fuel is exhausted.
C.
It takes tens of thousands of years for the radioisotopes in the rods to decay to safe levels.
D.
It is impossible to determine how long it will take for the radioisotopes to decay because they last too long.
Answer:
c
Explanation:
it takes 10,000 years to just reduce down the decay
What is the correct IUPAC name for Ir(NO₂)₄
Answer
Iridium(IV)Nitrite
The correct IUPAC name of the Ir(NO₂)₄ compound is Iridium(IV)Nitrite.
What is the IUPAC name?Whether it's in a continuous chain or just a ring, the largest chain of carbons joined by a single bond serves as the basis for IUPAC nomenclature.
What is a compound?
A chemical compound would seem to be a substance that contains numerous similar molecules made of atoms from different elements joined by chemical bonds.
The given compound is Ir(NO₂)₄. It can be seen that 4 nitro group is attached with Ir and its coordination number is 4. Hence, the IUPAC name will be Iridium(IV)Nitrite.
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Name the following alkane molecule:
Br
CI
A. 6-bromo-2-chlorodecane
B. 2-chloro-6-bromodecane
C. 5-bromo-9-chlorodecane
Answer:
6- bromo- 2-chlorodecane
The name of molecule is 6- bromo- 2-chlorodecane.
What is 6- bromo- 2-chlorodecane?
It is organic molecule. There are 10 carbon present in this molecule. The bromine atom is attached with C-6 carbon where chlorine is attached with C-2 carbon.
What is molecule?A molecule is a collection of more than one atom bound together by chemical bonds; depending on the context, the phrase may or may not include ions that meet this requirement.
Therefore, the name of the given molecule will be 6- bromo- 2-chlorodecane
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PLEASE HELP ASAP!!!
Answer:
I don't know What can I do.
What was Thomson's model of the atom called?
A. The oil-drop model
B. The photoelectric model
C. The plum-pudding model
D. The atomic theory model
Determine the kinds of intermolecular forces that are present in each of the following. Part A Xe Check all that apply. dispersion forces dipole-dipole forces hydrogen bonding Request Answer Part B N2 Check all that apply. dispersion forces dipole-dipole forces hydrogen bonding Request Answer Part C CO Check all that apply. dispersion forces dipole-dipole forces hydrogen bonding Request Answer Part D HF Check all that apply. dispersion forces dipole-dipole forces hydrogen bonding
Answer:
Part A
dispersion forces
Part B
dispersion forces
Part C
dispersion forces
dipole-dipole forces
Part D
dispersion forces
dipole-dipole forces
hydrogen bonding
Explanation:
Dispersion forces occur in all molecules. They result from momentary shifts in the electron cloud of molecules which induces a dipole in another molecule. This induced dipole eventually spreads throughout the molecule.
For Xe which is a noble gas and N2 which is a diatomic molecule, dispersion forces is the only kind of intermolecular force present in the molecule.
CO is a polar molecule hence in addition to dispersion forces, dipole-dipole forces also exist in the molecule.
HF is a polar molecule hence it possesses dipole-dipole forces in addition to dispersion forces. In this molecule, hydrogen is bonded to a highly electronegative atom (fluorine). Hence, hydrogen bonding is a dominant intermolecular interaction in the molecule.
Calculate the volume of a 89.51 g sample of carbon dioxide at 281.8 K and 843.9 torr. Round your answer
to the nearest L. Do not include units.
Answer:
1,000.000
Explanation:
Compare the modern (electron cloud) model of the atom with Bohr’s atomic model. Which of these statements describe the two models correctly? Check all of the boxes that apply.
A. Bohr’s model was replaced only because of its age.
B. Bohr’s model electrons cannot exist between orbits, but in the electron cloud model the location of the electrons cannot be predicted.
C. The modern model explains all available data about atoms; Bohr’s model does not.
D. The modern model is more widely accepted because it was proposed by more well known scientists.
Answer:
B. Bohr’s model electrons cannot exist between orbits, but in the electron cloud model, the location of the electrons cannot be predicted.
AND
C. The modern model explains all available data about atoms; Bohr’s model does not.
Explanation:
The answers are right on Edge. :)
Answer:
b and c
Explanation:
my assignment was 100% 2022
