Answer:
A
Explanation:
Took at test on this and my teacher said it was right, hopefully I remembered right, also I answered ur other question like this I think lol
A solution of EDTA is prepared by dissolving 1.986 grams of solid in approximately 500 mL of water. A standard calcium ion solution is then prepared by dissolving 0.2191 grams of chelometric calcium carbonate in HCl until dissolved, evaporating off the solvent, then redissolving into a 250.0 mL volumetric flask. A 25.00 mL aliquot of this calcium solution required exactly 26.18 mL of the EDTA solution to reach an Eriochrome Balck T endpoint. What is the concentration of the EDTA solution
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
Question 4 of 35
What did Thomson discover as a result of his experiments with cathode ray
tubes?
A. Electrons are found within electron clouds of atoms.
B. Each atom has a positive nucleus at its center.
C. Electrons travel along circular paths within atoms.
D. Atoms are made up of smaller subatomic particles
Answer:
D
Explanation:
Answer:
D Atoms are made up of smaller subatomic particles
Explanation:
I just took the quiz, I hope this helps!
Ramps make work easier by decreasing the amount of force needed to move an object by ______ the distance it travels.
A. reducing
B. increasing
C. equalizing
Identify the double displacement reaction
2NH3+H2SO4
Answer:
......................
nh42so4
Which statement is true about copper and salt?
If 33.9g NaCl are mixed into water and the total mass is 578g, what is the CHANGE in freezing if Kb= - 1.82C/M (molal)? Assume NaCl does not dissociate in solution.
Answer:
-1.82 °C
Explanation:
Step 1: Given data
Mass of NaCl (solute): 33.9 gMass of water (solvent): 578 g = 0.578 kgFreezing point depression constant for water (Kb): -1.82 °C/mStep 2: Calculate the molality of the solution
We will use the following expression.
m = mass of solute / molar mass of solute × kg of solvent
m = 33.9 g / 58.44 g/mol × 0.578 kg
m = 1.00 m
Step 3: Calculate the freezing point depression (ΔT)
The freezing point depression is a colligative property that, for a non-dissociated solute, can be calculated using the following expression:
ΔT = Kb × m
ΔT = -1.82 °C/m × 1.00 m
ΔT = -1.82 °C
Which statement describes a physical change? *
A. An iron bolt on a bridge rusts and weakens the bridge.
B. The surface of a silver cup turns black when it is exposed to air.
C. A sculptor casts a statue in molten bronze and allows it to harden.
D. Slivers of magnesium in fireworks form a bright glow as they burn.
The statement that describes a physical change is a sculptor casts a statue in molten bronze and allows it to harden. The correct option is C.
What are physical changes?"A physical change is one that simply affects the physical nature of the substance." Usually, increasing the temperature or applying pressure, both, will cause a physical change. In other words, physical changes are reversible.
All the other options like rusting of iron bolts on a bridge is a chemical change when iron reacts with oxygen in the air, it gets rust.
Similarly, silver cups exposed to air react with air is a chemical change, and option d, silver off magnesium that creates light, is also a chemical change.
Thus, the correct option is C. A sculptor casts a statue in molten bronze and allows it to harden.
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HELP FAST! PLEASE
This is due in 4 hrs!!!!! Ahhhh
The amplitude is greater for both
The frequency is for wave two
Explanation:
?Are you good.....
sailing 2
a)at
b)in
Answer:
A
Explanation:
common sense
Answer:
are you good at sailing A.
a sample of helium gas is in a sealed rigid container
is there a question or no? im confused.
How many moles of O2 are needed to react
with 24 moles of C2H6?
2C2H6 + 702 — 4CO2 + 6H20
Explanation:
Mole ratio of Ethane to Oxygen = 2 : 7
Moles of O2 needed = 24 moles * (7/2) = 84 moles.
Moles are the ratio of the mass and the molar mass of the substance. 84 moles of oxygen are needed to react with Ethane.
What are moles?Moles are the unit of the measurement of small entities like molecules, atoms, or particles.
The reaction is shown as:
[tex]\rm 2C_{2}H_{6} +7O_{2} \rightarrow 4CO_{2} + 6H_{2}O[/tex]
From the reaction, it can be said that the mole ratio of ethane [tex](\rm C_{2}H_{6})[/tex] and oxygen [tex](\rm O_{2})[/tex] is 2:7.
Then moles of oxygen will be,
[tex]24 \times \dfrac{7}{2} = 84[/tex]
Therefore, 84 moles of oxygen are needed to react with 24 moles of ethane.
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d = 7 V = 950 cm M = 95 g
0.1 g/cm3
0.1 cm3
90,250 g
90,250 g/cm3
Answer:
daddy chill
Explanation:
if you aint stephanie dont anwer
Answer:
wsp
Explanation:
Question 1 / 1
Which of the following is a covalent bond?
A. CO2
B. NaCl
C. Fe2O,
Answer:
Chemistry deals with matter, and there is a tremendous variety of matter in the universe. The behavior of matter depends on the type of elements that are present and on the structure of those elements—how they are connected to make a molecule. In this exercise, you will evaluate some representative models to develop the rules used to classify a compound, to predict the formula of a compound, and to name the compound. This exercise is just the beginning of the work needed to be done to master the rules of writing formulas and nomenclature. Your textbook has tables of the names and formulas of common cations and anions, and discusses the rules of nomenclature in detail. You will need to spend some time with this material, as the formal rules of nomenclature may not be presented in lecture, although they will certainly be used in discussions of Lewis structures and reaction chemistry.
Explanation:
In a covalent compound, valence electrons are shared between the two atoms in the bond. These can be evenly shared (covalent bond) or unevenly shared (polar covalent bond). In an ionic bond, electrons are localized to one of the atoms (giving it an overall negative charge), while the other atom has an overall positive charge. The difference in electronegativity between the two atoms in the bond can help predict whether the bond is likely to be ionic, covalent, or polar covalent, as can the type of atoms involved (metals or non-metals). A bond with two identical atoms is always pure covalent, while a covalent bond with two different atoms is likely to be polar covalent.
calculate the equivalent weight of acid on the basis of given reaction. NaoH + H2So4 gives NaHSo4 + H20.
Answer:
98
Explanation:
Based on the reaction:
NaOH + H2SO4 → NaHSO4 + H2O
Where 1 mole of the base (NaOH) reacts per mole of the acid (H2SO4)
The formula of equivalent weight is:
Equivalent weight = Molecular mass / Number of equivalent moles
Where Molecular mass of sulfuric acid is 98g/mol
And number of equivalent moles = 1 -Because 1 mole of acid reacts per mole of base
Equivalent weight is:
98 / 1 =
98
HELPPPPPPPPP 35 POINTSSSSSS!!!!!
A metal is oxidized if it’s converted from its metallic form to make a compound, and it’s reduced if it’s converted back to its metallic form.
FILL IN THE BLANKS with either "reduce" or "oxidize"
Magnesium is able to copper, and copper is able to magnesium.
Zinc is able to magnesium, and magnesium is able to zinc.
Copper is able to zinc, and zinc is able to copper.
Answer:
oxidize
Explanation:
What temperature units
should be used when
performing calculations using
Charles's Law?
Answer:
Kelvin (K) onlyExplanation:
Kelvin is preferred for solving problems related to Charles' Law because , it is the Absolute temperature scale.
To convert Celsius to Kelvin scale, you add 273 to the temperature in the centigrade/Celsius scale.
Pieces of DNA that pass genetic traits from parent to offspring are what?
A. Heredity
B. Phenotype
C. Gene
D. Allele
Pieces of DNA that pass genetic traits from parent to offspring are called as gene.
What is DNA?DNA is a hereditary material which is present in human beings as well as all other living organisms. Every cell which is present in an organism's body has DNA which is the same. Most of the DNA is situated in the cell's nucleus and small amount of it can be found in the cell's mitochondria as well.
Information which is stored in DNA is stored as codes made up of four chemical bases namely, adenine, thymine , cytosine and guanine.Human DNA consists of 3 billion bases .The order of the bases determines information which is required for building and maintaining an organism.
DNA bases are capable of pairing up with each other. Adenine pairs with thymine and guanine pairs up with cytosine .Each base is also attached to a sugar molecule and a phosphate group. A base, phosphate sugar are together called as nucleotides.
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describes the temperature at which a
solid's attractive forces are overcome and it
becomes a liquid.
Answer:
Melting point
Explanation:
it's constant temperature at which the bonds of a solid Crystal lattice are broken down by overcoming the attractive forces converting it to liquid
Based on the principle of complementary colors, which colors or wavelengths of light would you expect to be most strongly absorbed by Cu2 ions?
Answer:
Red and Orange
Explanation:
Complementary colors are those colours located across from each other on a color wheel. If we look at the colour wheel attached to this answer, we will see various complementary colours shown.
A good look at the attached colour wheel reveals that blue Cu2+ ions absorbs light around the red and orange portions of the visible spectrum.
Cups ans glasses are taking too long to air dry. This could be caused by
Answer: Servsafe 9
Explanation:
Remove food from the surface
clean the surface
rinse the surface
sanitize the surface
allow the surface to air dry
Cups and glasses are taking too long to air dry. This could be caused by the ventilation system not working properly. The correct option is D.
What is ventilation?A ventilation system is a mechanical device that is normally created and built to supply airflow into and out of a structure or other enclosed space. Because air is provided by a functioning ventilation system, moisture on surfaces like cups and glasses can dry more quickly.
It is possible to describe air-drying as a technique or process for removing moisture from surfaces using either heated, forceful, or dry air. Therefore, air drying aids in making the surface of goods like cups and glasses dry, or free of moisture.
Thus, the correct option is D. The ventilation system not working properly.
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The question is incomplete. Your most probably complete question is given below:
A. Incorrect timing of the wash cycle.
B. An improper use of chemical sanitizer.
C. The water temperature being too high.
D. The ventilation system not working properly.
Flicks tongue stuck to the floor Porter he was triple dog dare to do it if the teacher Miss shields calls for help in the firetruck 0 mph to 42 mph in six seconds what is a fire trucks acceleration?
HELP DUE MONDAY!!!
Answer:
3.128 m/s^2
Explanation:
Acceleration is the change in velocity over the change in time. Final velocity is 42 mph and initial velocity is 0 mph, but we need to convert these values to meters per second (m/s).
To do that, we divide 42 by 2.237 and the result is 18.77.
Now we can calculate the change in velocity: 18.77 - 0 = 18.77 m/s.
Now we need the change in time: 6 s is the elapsed time, 0 s in the starting time. So 6 s - 0 s = 6 s.
Now we divide 18.77 by 6 s and obtain the answer, which is:
18.77 m/s ÷ 6 s = 3.128 m/s^2
Experiment: Turn on Show electronegativity. Electronegativity (EN) describes how strongly an atom attracts a pair of shared electrons. The higher the EN value, the greater the tendency of an atom to hold onto electrons in a bond and become negatively charged. Electronegativity difference is found by subtracting the EN value of one atom from another. Choose two nonmetals with a small (or no) EN difference between them. Click Play. What happens to the shared electrons in this bond
Answer:
See explanation
Explanation:
If we take two nonmetals with little or no electronegativity difference between them, the shared electrons are not attracted greatly towards any of the bonding atoms. In other words, the shared electrons remain equidistant between the nuclei of the two bonding atoms.
The bond is nonpolar since polarity is introduced into covalent bonds by a significant difference in electronegativity of the bonding atoms.
a) Calculate the standard reaction entropy for the combustion of methane to carbon dioxide and liquid water at 298 K. b) Calculate the standard reaction entropy for the hydrolysis of liquid water to form oxygen and hydrogen gas. c) Do your results in (a) and (b) agree with the general rule that reaction entropies are positive if there is a net formation of gas in a reaction, and negative if the is a net reduction of gas?
Answer: (a) [tex]\Delta S^{0}[/tex] = - 242.2J/K.mol
(b) [tex]\Delta S^{0}[/tex] = 163.34J/K.mol
(c) Yes
Explanation: Entropy is the measure of randomness or disorder of a system. Standard Entropy has the symbol [tex]S^{0}[/tex].
Mathematically, Entropy is defined as
[tex]\Delta S^{0}=\Sigma S^{0}(products)-\Sigma S^{0}(reagents)[/tex]
Each substance has its own entropy value.
(a) Combustion of Methane:
[tex]CH_{4}+2O_{2}[/tex] ⇒ [tex]CO_{2}+2H_{2}O[/tex]
Using standard entropy table, entropy will be:
[tex]\Sigma S^{0}(products)=214+2(69.91)[/tex] = 353.8
[tex]\Sigma S^{0}=186.264+2(205.138)[/tex] = 596.54
[tex]\Delta S^{0}=[/tex] 353.8 - 596.54
[tex]\Delta S^{0}=[/tex] - 242.2
Standard Entropy for combustion of methane is [tex]\Delta S^{0}=[/tex] - 242.2 J/K.mol.
(b) Hydrolysis of Water:
[tex]H_{2}O_{(l)}[/tex] ⇒ [tex]H_{2}_{(g)}+1/2O_{2}_{(g)}[/tex]
[tex]\Sigma S^{0}(products)=130.684+0.5(205.138)[/tex] = 233.253
[tex]\Sigma S^{0}(reagents)=69.91[/tex]
[tex]\Delta S^{0}=[/tex] 233.253 - 69.91
[tex]\Delta S^{0}=[/tex] +163.34
Standard Entropy for hydrolysis of water is [tex]\Delta S^{0}=[/tex] + 163.34 J/K.mol
(c) Yes, the results prove the general rule: Reactions Entropies are positive for net formation of gas and negative for net reduction of gas. This happens because, as entropy is the measure of disorder, the entropy for gases are greater than for liquids and solids. So, when there is formation of a gas, Entropy increases and when there isn't, entropy decreases.
How many grams of oxygen, O2 are produced if 52.0g of potassium chlorate, KClO3, decomposes? (The molar mass of O2 = 32 g/mol and the molar mass of KClO3 = 122.4 g/mol).
Answer:
20.39 g of O2.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2KClO3 —> 2KCl + 3O2
Next, we shall determine the mass of KClO3 that decomposed and the mass of O2 produced from the balanced equation. This is illustrated below:
Molar mass of KClO3 = 122.4 g/mol
Mass of KClO3 from the balanced equation = 2 × 122.4 = 244.8 g
Molar mass of O2 = 32 g/mol
Mass of O2 from the balanced equation = 3 × 32 = 96 g
Summary:
From the balanced equation above,
244.8 g of KClO3 decomposed to produce 96 g of O2.
Finally, we shall determine the mass of O2 produced from the decomposition of 52 g of KClO3. This can be obtained as follow:
From the balanced equation above,
244.8 g of KClO3 decomposed to produce 96 g of O2.
Therefore, 52 g of KClO3 will decompose to produce =
(52 × 96)/244.8 = 20.39 g of O2.
Thus, 20.39 g of O2 is produced.
Based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation:
(
)BaO2 + (
)H2SO4 → (
)H2O2 + (
)BaSO4
Answer:
1
1
1
1
Explanation:
the equation is balancing
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
What will happen to the following equilibrium if Cl2
was removed ?
4HCI(9) + O2(9) = 2012(9) + 2H20(9)
The following equilibrium will shift in the direction of the product:
Further explanationGiven
Reaction
4HCl + O₂ → 2H₂O + 2Cl₂
Cl₂ was removed
Required
Equilibrium changes
Solution
Reaction = - action
adding the products ⇒ Shifts in the direction of the reactants
reducing the products ⇒Shifts in the direction of the products
Cl₂ as a product, so if Cl₂ is taken or reduced, the reaction will try to maintain system equilibrium by moving to the right (product formation) ⇒ Shift in the direction of the product:
what tools are used specifically for earth science
Geologic Tools. Geologists use a lot of tools to aid their studies. Some of the most common tools used are compasses, rock hammers, hand lenses, and field books.
hope this helped <3
HELPPPPPPP
is this chemical or physical reaction
Answer:
Chemical reaction
Explanation:
It's creating a whole other substance