Answer:
0.02088M of EDTA
Explanation:
The Ca²⁺ is chelated in presence of EDTA in a relation 1:1, when there is no free Ca²⁺ the eriochorme black T change its colour showing endpoint.
Thus, we need to find final concentration of Ca²⁺ solution and, thus, we can find concentration of the EDTA solution:
Molarity Ca²⁺ solution:
0.2191g * (1mol / 40.08g) = 0.005467 moles of Ca²⁺ in 250mL = 0.250L:
0.005467 moles of Ca²⁺ / 0.250L = 0.02187M
Moles of Ca²⁺ added:
0.025L * (0.02187 mol / L) = 5.467x10⁻⁴ moles of Ca²⁺ = Moles of EDTA at endpoint.
Molarity EDTA:
5.467x10⁻⁴ moles EDTA / 0.02618L = 0.02088M of EDTA
you weigh out 43.9 g of potassium (K). How many moles of potassium did you weigh? How many atoms?
Answer:
1.12 moles of potassium
6.76x10²³ atoms of potassium
Explanation:
In order to convert g of potassium to moles, we need to use its molar mass (which we can find via the periodic table):
Molar Mass of K = 39.09 g/mol43.9 g K ÷ 39.09 g/mol = 1.12 mol KThen, to convert moles into atoms, we use Avogadro's number (6.023x10²³ atoms per mole):
1.12 mol K * 6.023x10²³[tex]\frac{atoms}{mol}[/tex] = 6.76x10²³ K atomsabout how much of the visible side of the moon is lit up during a full moon?
A. Three fourths
B. One fourth
C. None of it
D. All of it
Answer:
D
Explanation:
i learned this in elementary
Please help will give brainliest
Answer:
the answer id D
Explanation:
i dont know im just living here 5
what is the kinetic energy of a 3kg ball that is rolling at 2 meters per second
Answer:
6 JExplanation:
The kinetic energy of an object can be found by using the formula
[tex]k = \frac{1}{2} m {v}^{2} \\ [/tex]
m is the mass
v is the velocity
From the question we have
[tex]k = \frac{1}{2} \times 3 \times {2}^{2} \\ = \frac{1}{2} \times 3 \times 4 \\ = 3 \times 2[/tex]
We have the final answer as
6 JHope this helps you
What is immigration and emigration
Answer:
well for me I think
Explanation:
immigration is the movement which involves an individual moving from a present place to another environment
That is going out
WHILE
Emigration is the process where a person comes into a particular environment
That means coming in
velocity is a ______ quantity
Answer:
vector quantity
Explanation: Brainliest pls
How many moles of Fe2+ are there in a 2.0g sample that is 80% by mass of FeCl2?
The number of moles of [tex]Fe^{2+}[/tex] in the [tex]2.0g[/tex] sample of [tex]FeCl_{2}[/tex] is [tex]0.0157[/tex] moles.
The following points should be noted about the number of moles:
The number of moles of any substance can be calculated using the mass and molar mass of the substance. [tex]n = \frac{mass}{molarmass}[/tex], where n is the number of moles.Mass of the sample given as [tex]2.0g[/tex] and the molar mass of the sample as [tex]126.75g/mol[/tex].
Therefore, the number of moles of [tex]Fe^{2+}[/tex]is obtained by dividing the mass by the molar mass.
Hence the number of moles is obtained as [tex]0.0175[/tex] moles.
Learn more about the number of moles here:
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Please help with this....thank you
Answer:
large cracks suddenly form
Explanation:
the tectonic plates begin to move causing cracks. I think
Which three are advantages of asexual reproduction?
A:Offspring are more likely to survive environmental changes.
B:Some offspring are more likely to survive a disease.
C:Less energy is required to reproduce.
D:The population can increase from only one parent.
E:The population can increase quickly.
Answer:
sorry if I get this wrong I think it is C
Explanation:
Please answer it truthfully please
Answer:
False
Explanation:
Chemical and Physical changes happen uniquely, they cannot happen at the same time. When you crumble a piece of paper you don't change its chemical form you change its physical form. When a piece of metal rusts its chemical composition changes, leading me to believe it is false.
Good luck on the rest of your assignment/test!
someone plz help me write notes (images attached)
Answer:
kya karna parega hume....???
Please help Fast i dont Know
Complete the statement of equality.
Answer:
This is not a viable question.
Explanation:
which 2 not one 2! hjmdnxhjund
Answer:
A and D then I guess
Explanation:
sorry hope this helps!
A biochemist carefully measures the molarity of magnesium ion in of cell growth medium to be . Unfortunately, a careless graduate student forgets to cover the container of growth medium and a substantial amount of the solvent evaporates. The volume of the cell growth medium falls to . Calculate the new molarity of magnesium ion in the cell growth medium. Be sure your answer has the correct number of significant digits.
Answer:
760 uM
Explanation:
A biochemist carefully measures the molarity of magnesium ion in 47, mL of cell growth medium to be 97 uM. Unfortunately, a careless graduate student forgets to cover the container of growth medium and a substantial amount of the solvent evaporates. The volume of the cell growth medium falls to 6.0 mL. Calculate the new molarity of magnesium ion in the cell growth medium Be sure your answer has the correct number of significant digits.
The problem here is that the amount of magnesium ion remains the same irrespective of the volume.
Amount of magnesium in the growth medium = molarity x volume
= 97 x [tex]10^{-6}[/tex] x 47 x [tex]10^{-3}[/tex] = 4.559 x [tex]10^{-6}[/tex]
Then, the volume reduced to 6.0 mL, the new molarity becomes;
molarity = mole/volume
= 4.559 x [tex]10^{-6}[/tex]/6 x [tex]10^{-3}[/tex] = 7.598333 x [tex]10^{-4}[/tex] M = 759.83333 uM
To the correct number of significant digits = 760 uM
HELPPPPPPP
is this chemical or physical reaction
Answer:
Chemical reaction
Explanation:
It's creating a whole other substance
Atoms of the same element can have different properties. ( true or false )
Answer:
Atoms of the same element have the same chemical properties. The only differences between atoms of the same element are the number of neutrons in the nucleus and the atomic weight of each isotope. false
Answer:
False
Explanation:
Different elements can have different properties, but not atoms of the same element
The percent ionization of a 0.350 M HC,H,O2 solution. Ka(HC2H302)
Answer:
The answer is 56
Explanation:
i need points
PLEASEEE HELP ?!?!?!
which of the following processes provide evidence of the particulate nature of matter
I. Diffusion
II. Filtration
III. Osmosis
A. I and II only
B. I and III only
C. II and III only
D. I, II and III
Answer:
B
Explanation:
I think the answer is Diffusion and Osmosis
The processes that provide evidence of the particulate nature of matter would be diffusion and osmosis.
Matter is defined as anything with mass/weight and able to occupy space. Matters could be molecules of solid, liquid, or gases. The molecules of each category of matter have their specific characteristics.Molecules of liquids and gases are able to diffuse. Diffusion is defined as the movement of molecules from the region of high concentration to the region of low concentration. Molecules of solids in the dissolved form are also able to diffuse. Water molecules are also able to move from the region of high to the region of low water potentials by osmosis in the presence of a semi-permeable membrane.Thus, both diffusion and osmosis back up the particulate nature of matter.
More on the particulate nature of matter can be found here: https://brainly.com/question/15230454?referrer=searchResults
Help me if you know this pleaseeee
Answer:
help you with what?
Explanation:
Robert makes a glass of tea and takes it outside with him. While outside, the thermal energy within the glass of tea is transferred to its surroundings. Based on this information, what else is happening within the glass of tea?
A.
The kinetic energy of the particles is increasing and the temperature is decreasing.
B.
The kinetic energy of the particles is increasing and the temperature is increasing.
C.
The kinetic energy of the particles is decreasing and the temperature is increasing.
D.
The kinetic energy of the particles is decreasing and the temperature is decreasing.
Answer:
A
Explanation:
i had answer it and it was A
Name one way that the scientific community has honored Mendeleev’s contribution to science.
Answer:
Mendeleev's greatest contribution to science is certainly the Periodic Table of Elements, which says the properties of basic elements repeat periodically when they are arranged by their atomic number. He made the discovery in 1869 during his work on the award-winning textbook on chemistry basics.
Inventions: Periodic table, Pyrocollodion
Explanation:
*Hope this helps*
Answer:
Mendeleev's greatest contribution to science is certainly the Periodic Table of Elements, which says the properties of basic elements repeat periodically when they are arranged by their atomic number. He made the discovery in 1869 during his work on the award-winning textbook on chemistry basics.
Inventions: Periodic table, Pyrocollodion
Explanation:
Giselle is working with a chemical substance in a laboratory. She observes that when the chemical is heated, it gives off a gas. She assumes that the gas is oxygen but decides to test this assumption to verify it. Which type of scientific knowledge is Giselle’s assumption? A. fact B. hypothesis C. law D. observation E. theory
Answer:
The correct answer is B. Hypothesis
Explanation:
I am a nonmetal.I am in the Oxygen family and in row 3.I have 6 valence electrons.I am yellow and have a stinky smell.Who am i
Answer:
sulfur
Explanation:
In oxygen family sulfur has yellow color and also having stinky smell. Thus given statements are about sulfur.
It is present in oxygen family.
It has six valance electrons.
Its atomic number is 16.
Its atomic weight is 32 amu.
The electronic configuration of sulfur is given below,
S₁₆ = 1s² 2s² 2p⁶ 3s² 3p⁴
We can see the valance shell is third shell and it have six electrons thus sulfur have six valance electrons. (3s² 3p⁴ )
Sulfur is used in vulcanisation process.
It is used in bleach and also as a preservative for many food.
it is used to making gun powder.
Scientists use _____ as chemical symbols.
dots
letters
shapes
lines
Answer:
Letters
Explanation:
Answer:
Letters
Explanation:
Chemical symbols are used to standardize the 'language of chemistry' and to identify elements and atoms in a chemical formula easily. Chemical symbols consist of one or two letters, most often derived from the name of the element.
Which of the following elements in a nonmetal? *
Zinc (Zn)
O Barium (Ba)
Krypton (Kr)
Lithium (Li)
Answer:
Krypton (Kr)
Explanation:
Nonmetals are the elements that have opposing features and characteristics of metals. Nonmetals do not shine and are dull in appearance. They are bad conductors of heat and electricity. They are brittle and cannot be beaten into sheets. The density, melting and boiling points of the nonmetals are low. Krypton (Kr) is a non metal whose atomic number is 36.
which of the following could be classified as producing a physical change?
What are the coefficients for the reaction _Cl2O5 + _H2O → _HClO3 once it is balanced?
1, 1, 1
1, 1, 2
1, 2, 2
2, 1, 1
Answer:
1, 1, 2
Explanation:
Answer:
Answer is B. 1, 1, 2
Explanation:
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What are the respective central-metal oxidation state, coordination number, and overall charge on the complex ion in Na2[Cr(NH3)2(NCS)4]?
A) +3; 6; -1
B) +2; 6; -2
C) +1; 6; -2
D) +3; 6; +1
Answer:
B) +2; 6; -2
Explanation:
In order to know what the coordination number is, all we need to do is to count the number of ligands present in the coordination sphere. Coordination number refers to the number of ligands in the coordination sphere of a given complex. The coordination number here is 6.
The counter ion here is 2Na+. It means that the overall charge on the complex must be -2 because the magnitude of charge on the complex ion is exactly balanced by the number of counter ions.
The charge on the metal (x) must now be;
x + 0 + 4(-1) = -2
x - 4 = -2
x = -2 + 4
x = +2
Note that NH3 is designated as zero because it is a neutral molecule. Each NCS^- ion has a charge magnitude of -1.
In the reaction shown below, which substance is oxidized?
2Na + CuSO4 → Na2SO4 + Cu
A. Na
B. Na2SO4
C. Cu
D. CuSO4
Answer:
Na
Explanation:
Because sodium loses one electron and becons Na+ and sodium oxidizes
Los of electron is oxidation
Na is oxidised in the given reaction 2Na + CuSO[tex]_4[/tex] → Na[tex]_2[/tex]SO[tex]_4[/tex] + Cu. Therefore, the correct option is option A.
What is oxidation?When the oxidation state of either a molecule, atom, or ion increases, this is referred to as oxidation. The inverse process is termed reduction, and it happens when electrons are gained when the oxidation status of such an atom, molecule, as well as ion lowers.
When a chemical species oxidizes, its oxidation state rises. Oxidation does not always need the presence of oxygen! The phrase was first used when oxygen induced electron loss inside a process. The present definition is broader. Na is oxidised in the given reaction 2Na + CuSO[tex]_4[/tex] → Na[tex]_2[/tex]SO[tex]_4[/tex] + Cu.
Therefore, Na is oxidised in the given reaction 2Na + CuSO[tex]_4[/tex] → Na[tex]_2[/tex]SO[tex]_4[/tex] + Cu. The correct option is option A.
To learn more about oxidation, here:
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