Answer:
2.5%
Explanation:
Given
M1 = 7.50%
M2 = ?
V1 = 25.0mL
V2 = 75.00mL
M1V1=M2V2
7.5x25=M2x75
M2=2.5%
The NaCl of a solution made by diluting 25.0 ml of a 7.50 (m/v)% NaCl solution to a total volume of 75.00 ml is 2.5 (m/v)%.
What is solution?Solution is defined as a continuous variation of two or more substances in their relative proportions up to what is known as the limit of solubility. A solute is the name for the substance that dissolves to create a solution. A solvent is the material that a solute will dissolve in. Sugar is the solute and water is the solvent in a sugar-water solution.
To calculate the molarity of NaCl
We use M1V1 = M2V2
Given M1 = 7.50 (m/v)%
V1 = 25.0 ml
V2 = 75.0 ml
M2 = M1 V1 / V2
M2 = 7.50 x 25.0 / 75.0
M2 = 2.5 (m/v)%
Thus, the NaCl of a solution made by diluting 25.0 ml of a 7.50 (m/v)% NaCl solution to a total volume of 75.00 ml is 2.5 (m/v)%.
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A solution of cough syrup contains 5.00% active ingredient by volume. If the total volume of the bottle is 80.0 mL , how many milliliters of active ingredient are in the bottle?
Answer:
someone is in my mind and it is telling me 5.55m
Explanation:
Answer:
4 mL
Explanation:
4mL is 5% of 80mL. Therefore my answer is right.
Now consider a sample of the gas at 33 deg C, 744 mm Hg, and 450 mL. If the pressure is decreased to 725 mm Hg and the temperature raised to 66C. What is the new volume of the gas? New volume =
Answer:
V₂ = 511.59mL
Explanation:
Given data:
Initial volume = 450 mL
Initial pressure = 744 mmHg
Initial temperature = 33°C (33 +273 = 306 K)
Final temperature = 66°C (66+273 = 339 K)
Final pressure = 725 mmHg
Final volume =?
Formula:
P₁V₁/T₁ = P₂V₂/T₂
P₁ = Initial pressure
V₁ = Initial volume
T₁ = Initial temperature
P₂ = Final pressure
V₂ = Final volume
T₂ = Final temperature
Solution:
V₂ = P₁V₁ T₂/ T₁ P₂
V₂ = 744 mmHg × 450 mL × 339 K / 306 K ×725 mmHg
V₂ = 113497200 mmHg .mL. K / 221850 K.mmHg
V₂ = 511.59mL
28. Element X is powerful enough to reduce sodium ions to sodium metal. Barium is a strong enough reducing agent to reduce X +to X. What is the identity of element X? _____________
Answer:
hope it's correct.
Explanation:
element is nickel.
A 0.2 g sample of pyrolusite is analyzed for manganese content as follows. Add 50.0 mL of 0.1 M solution of ferrous ammonium sulfate to reduce the MnO2 to Mn2 . After reduction is complete, the excess ferrous ion is titrated in acid solution with 0.02 M KMnO4, requiring 15.0 mL. Calculate the percent manganese in the sample as Mn3O4.
Answer:
66.7%
Explanation:
The reaction for the titration of the excess ferrous ion is:
5Fe⁺² + MnO₄⁻ + 8H⁺ → 5Fe³⁺ + Mn²⁺ + 4H₂OWe calculate the moles of Fe⁺² from the used moles of KMnO₄:
0.02 M * 15.0 mL = 0.30 mmol KMnO₄0.3 mmol KMnO₄ * [tex]\frac{5mmolFe^{+2}}{1mmolKMnO_4}[/tex] = 1.5 mmol Fe⁺²Then we substract those 0.30 mmol from the original amount used:
0.1 M * 50.0 mL = 5.0 mmol Fe⁺²5.0 - 1.5 = 3.5 mmol Fe⁺²The reaction between ferrous ammonium sulfate and MnO₂ is:
2Fe⁺² + MnO₂ + 4H⁺ → 2Fe³⁺ + Mn²⁺ + 2H₂OSo we convert those 3.5 mmol Fe⁺² that were used in this reaction to MnO₂ moles:
3.5 mmol Fe⁺² * [tex]\frac{1mmolMnO_2}{2mmolFe^{+2}}[/tex]= 1.75 mmol MnO₂Then we convert MnO₂ to Mn₃O₄, using the reaction:
3MnO₂ → Mn₃O₄ + O₂1.75 mmol MnO₂ * [tex]\frac{1mmolMn_3O_4}{3mmolMnO_2}[/tex] = 0.583 mmol Mn₃O₄Finally we convert Mn₃O₄ moles to grams:
0.583 mmol Mn₃O₄ * 228.82 mg/mmol = 133.40 mg Mn₃O₄And calculate the percent
0.2 g = 200 mg133.40 / 200 * 100% = 66.7%Where do karst regions occur?
Answer:
Image result for Where do karst regions occur?
Karsts are found in widely scattered sections of the world, including the Causses of France; the Kwangsi area of China; the Yucatán Peninsula; and the Middle West, Kentucky, and Florida in the United States.
Explanation:
Answer:
Middle West Kentucky.
Explanation:
Karst are found in widely scatter sections of the world.
A car's fuel efficiency is 39.0 miles per gallon. What is its fuel efficiency in kilometers per liter? (1.6094 km=1 mile)(1 gallon=3.79 L)
Answer:
the fuel efficiency in kilometers per liter is 16.561 kilometer per liter
Explanation:
The computation of the full efficiency in kilometers per liter is shown below:
39.0 miles ÷ gallon = (39.0 miles ÷ gallon) × (1.6094 km ÷ 1 miles) × (1 gallon ÷ 3.79 L)
Now cut the opposite miles and gallons
So, the fuel efficiency would be
= 16.561 kilometers per liter
Hence, the fuel efficiency in kilometers per liter is 16.561 kilometer per liter
3. Find
out the initial energy level (n) of an electron that results in the emi ssion of light of
wavelength 486 nm in the Balmer series?
Answer:
4
Explanation:
The Balmer series refers to a series of spectral emission lines of the hydrogen atom arising from electronic transitions from any higher level and terminating at the the energy level n= 2.
Using the relation;
1/λ = 1.09737*10^7 (1/2^2 -1/n^2initial)
We now have;
1/486 *10^-9 = 1.09737*10^7 (1/2^2 -1/n^2initial)
0.1875 = 1/2^2 -1/n^2initial
1/n^2initial = 1/2^2 - 0.1875
1/n^2initial = 0.0625
n^2initial = 16
ninitial = 4
state the difference between spermatozoon and spermatogonium
Answer:
spermatozoon:A spermatozoon is a motile sperm cell or moving from of the haploid cell that is the male gamete.
spermatogonium : A cell produced at an early stage in the formation of spermatozoa, formed in the wall of a seminiferous tuble and giving rise by mitosis to spermatocytes.
What is pure convalent bond
Answer:
Pure covalent bonds exist between two atoms with the same electronegativities. A pure covalent bond has no ionic character at all. Diatomic elements are good examples of pure covalent bonds where the electrons are evenly shared between both nuclei.
Explanation:
Hope this helped!
How does temperature effect the molecules of a substance that is dissolved.
Explanation:
Generally, temperature increases the rate of any chemical reaction considerably.
In a dissolution process, the solute is solvated in the solvent. Solutes are usually the solids or liquids being dissolved in the solution.
When temperature increases, the average kinetic energy of the solvent molecules increase also. The indicator of the average kinetic energy in a body is heat. As molecules begins to move rapidly, it brings both the solvent and solute in contact faster with each other.how to do question no 17
Explanation:
even I don't know this answer
but maybe you can solve it by putting the formula
Pre-Lab Questions
Which of the following are considered matter?
electricity
fire
air
water
Answer:
Fire, Air, Water.
Explanation:
Matter is anything that has mass and occupies space. However, not all form of matter are visible. Air is an example of invisible matter.
Note, electricity does not have mass or does not occupy space. Therefore, electricity is not a matter.
Answer:
Fire, Air, Water
Explanation:
Electricity is the of charged particles conducting medium. However, it is the electrons that are matter, not their movement.
Matter is anything that has mass and occupies space. The flame itself is a mixture of gases and so is matter. The light and heat produced are energy not matter.
Like solids and liquids, air is matter. It has a weight and it takes up space.
Water is a liquid and liquids are one of the four fundamental states of matter.
A competitive high school swimmer takes 56.7 seconds to swim 100. yards. What is his rate in m/min?
m
min
Answer:
96.72 m/min
Explanation:
The following data were obtained from the question:
Time (t) = 56.7 s
Distance (d) = 100 yard
Rate (R) =?
Next, we shall convert 56.7 s to minutes. This can be obtained as follow:
60 s = 1 min
Therefore,
56.7 s = 56.7 s × 1 min /60 s
56.7 s = 0.945 min
Next, we shall convert 100 yard to metre (m). This can be obtained as follow:
1 yard = 0.914 m
Therefore,
100 yard = 100 yard × 0.914 m /1 yard
100 yard = 91.4 m
Finally, we shall determine the rate of the swimmer as follow:
Time (t) = 0.945 min
Distance (d) = 91.4 m
Rate (R) =?
R = d/t
R = 91.4/0.945
R = 96.72 m/min
Thus the rate of the swimmer is 96.72 m/min
Plz what’s the answer to this
Answer: E
Explanation:hope this helps you out
Demonstrate how you can prepare 250ml 0.25M hydrogen peroxide from a solution of 20g/100ml of hydrogen peroxide.
To prepare 250 ml 0.25 M hydrogen peroxide, 10.63 ml of 20g/100 ml hydrogen peroxide has been taken and made up the volume to 250 ml.
The dilution of the sample can be prepared with the help of expression:
M1V1 = M2V2
M1 = molarity of the concentrated solution
V1 = volume of concentrated solution
M2 = molarity of diluted solution
V2 = volume of diluted solution.
The molarity of concentrated solution has been:
Molarity = [tex]\rm \dfrac{weight}{molecular\;weight}\;\times\;\dfrac{1000}{Volume\;(ml)}[/tex]
The 20g/100 ml Hydrogen peroxide has molarity:
Molarity = [tex]\rm \dfrac{20}{34.0147}\;\times\;\dfrac{1000}{100}[/tex]
Molarity of Hydrogen peroxide = 5.879 M
The volume of 5.879 M hydrogen peroxide is required to prepare 0.25 M hydrogen peroxide has been:
Volume of Hydrogen peroxide (20g/100 ml) [tex]\times[/tex] 5.879 = 250 ml [tex]\times[/tex] 0.25 M
Volume of Hydrogen peroxide (20g/100 ml) = 10.63 ml.
To prepare 250 ml 0.25 M hydrogen peroxide, 10.63 ml of 20g/100 ml hydrogen peroxide has been taken and made up the volume to 250 ml.
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What is the IUPAC name of this compound? ________ CH3-CHCl-CH2-CH2-Cl
Answer:
The prefixes are fluoro-, chloro-, bromo-, and iodo-. Thus CH 3CH 2Cl has the common name ethyl chloride and the IUPAC name chloroethane. Alkyl halides with simple alkyl groups (one to four carbon atoms) are often called by common names.05/06/2019
The IUPAC name of this compound is 2,3- dichlorobutane.
What is compound?Compound is defined as a chemical substance made up of identical molecules containing atoms from more than one type of chemical element.
Molecule consisting atoms of only one element is not called compound.It is transformed into new substances during chemical reactions. There are four major types of compounds depending on chemical bonding present in them.They are:
1)Molecular compounds where in atoms are joined by covalent bonds.
2) ionic compounds where atoms are joined by ionic bond.
3)Inter-metallic compounds where atoms are held by metallic bonds
4) co-ordination complexes where atoms are held by co-ordinate bonds.
They have a unique chemical structure held together by chemical bonds Compounds have different properties as those of elements because when a compound is formed the properties of the substance are totally altered.
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A carbocation is an example of a(an) ____. Does a carbocation accept a pair of electrons, or does it donate a pair of electrons?
A. Electrophile. The carbocation accepts a pair of electrons.
B. Nucleophile. The carbocation accepts a pair of electrons.
C. Electrophile. The carbocation donates a pair of electrons.
D. Nucleophile. The carbocation donates a pair of electrons.
Answer:
Option A. The carbocation accepts a pair of electrons.
Explanation:
A carbocation is defined as a positively charged carbon, which is bound to 3 substituents. Since it has no electrons nonbonding, it only has six electrons in its valence shell. With only six electrons in its valence shell, a carbocation is a powerful electrophile (and Lewis acid) and can react with any nucleophile that is found.
Carbocations are proposed as intermediates in many organic reactions. They also work like free radicals, which are electron-deficient species.
Same as free radicals, the carbocations are stabilized by alkyl substituents.
Which of the following statements correctly describes the function of cell parts?
A. The cell membrane determines which type of cell will develop.
B. The nucleus contains all the nutrients that the cell needs.
C. The mitochondria are the power plants of the cell.
D. The genes contain hemoglobin.
The statements correctly describes the function of cell parts is the mitochondria are the power plants of the cell. Therefore, option C is correct.
What do you mean by the mitochondria ?The cytoplasm of a cell contains tiny structures (fluid that surrounds the cell nucleus). The majority of a cell's energy is produced by mitochondria, which also have unique genetic material distinct from that present in the nucleus.
Oxidative phosphorylation, which produces ATP using the energy generated during the oxidation of the food we ingest, is the traditional function of mitochondria.
For the majority of biochemical and physiological activities, including growth, mobility, and equilibrium, ATP is used as the main energy source in turn.
Thus, option C is correct.
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Which of these is NOT evidence that a chemical change has taken place?
temperature rising when 2 substances are mixed
gas production
color change
melting
How many centimeters are in .479 kilometers
Answer:
47900 cm
General Formulas and Concepts:
Chemistry
Base 10 Decimal SystemUsing Dimensional AnalysisExplanation:
Step 1: Define
0.479 km
Step 2: Identify Conversions
1 km = 1000 m
1 m = 100 cm
Step 3: Convert
[tex]0.479 \ km(\frac{1000 \ m}{1 \ km} )(\frac{100 \ cm}{1 \ m} )[/tex] = 47900. cm
Step 4: Check
We are given 3 sig figs. Follow sig fig rules.
47900. cm ≈ 47900 cm
Suppose of sodium chloride is dissolved in of a aqueous solution of silver nitrate. Calculate the final molarity of chloride anion in the solution. You can assume the volume of the solution doesn't change when the sodium chloride is dissolved in it. Be sure your answer has the correct number of significant digits.
Suppose of sodium chloride is dissolved in of a aqueous solution of silver nitrate. Calculate the final molarity of chloride anion in the solution. You can assume the volume of the solution doesn't change when the sodium chloride is dissolved in it. Be sure your answer has the correct number of significant
How do the physical and chemical properties the halogens compare with those of the noble gases?
Explanation:
To form bonds with noble gases, a lot of energy is required to form those bonds. Halogens, on the other hand, are extremely reactive. ... The halogens tend to be very reactive, while the noble gases are in no way reactive and don't bond easily, if at all.
What is the compound name for HgCl2
Answer:
Mercury Chloride
Explanation:
Trust me, this answer is correct.
Calculate the internal energy of a system (in kiloJoules) that absorbs 14.73 kJ while being compressed with a pressure of 1.54 atm from 5.72 L to 1.0 L. Answer to one decimal space.
The internal energy of a system : 21.9 kJ
Further explanationThe laws of thermodynamics 1 state that energy can be changed but cannot be destroyed or created
The equation is:
ΔU=Q+W
Energy owned by the system is expressed as internal energy (U)
The sign rules for heat and work are set as follows:
• The system receives heat, Q +
• The system releases heat, Q -
• The system does work, W -
• the system accepts work, W +
The system absorbs 14.73 kJ⇒Q=+14.kJ
The system compressed⇒work done on the gas⇒W=+
W=-PΔV
[tex]\tt W=-1.54(1-5.720)\\\\W=7.2688[/tex]
[tex]\tt internal~energy(\Delta U)=Q+W\\\\\Delta U=14.73+7.2688\\\\\Delta U=21.9[/tex]
Write the balanced equation for the neutralization reaction between H3PO4 and NaOH in an aqueous solution.
Answer:
H3PO4 + 3NaOH ==> Na3PO4 + 3H2O
The balanced equation for the given reaction is [tex]3NaOH+H_3PO_4---- > Na_3PO_4+3H_2O[/tex]
What is neutralization reaction?A chemical reaction in which an acid and a base react quantitatively with each other is known as neutralization.
In a water reaction, neutralization means that there is no excess of hydrogen or hydroxide ions in the solution.
A neutralization reaction occurs when an acid and a base react to form water and a salt through the combination of H+ ions and OH- ions. The pH of neutralization of a strong acid and a strong base is 7.
Three moles of sodium hydroxide are required for one mole of phosphoric acid. The balanced equation tells us the following: 1 mol of H3PO4 reacts with 3 mol of NaOH.
It can be written as
[tex]3NaOH+H_3PO_4---- > Na_3PO_4+3H_2O[/tex]
Thus, this is the balanced equation for the given neutralizing reaction.
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Which process is shown in the diagram?
0,
ing
CO, +H,0
Chloroplast
Mitochondrion
Sugar
Heat
o
ATP
Respiration
The cellular respiration process, which generates ATP as the final result, employs oxygen and sugar as reactants. So, the correct option is A.
What is Cellular respiration?Cellular respiration is the process by which organisms combine oxygen with food molecules, channeling the chemical energy from those resources into life-sustaining activities while eliminating carbon dioxide and water as waste.
Both oxygen and glucose are reactants in the mobile respiratory system. ATP is the primary component of mobile respiration; waste products include carbon dioxide and water.
Oxygen might be present or absent while cells are respiring. Nonetheless, the activity is essentially known as "cellular respiration" because the cell seems to "respire" by consuming molecular oxygen (as an acceptor of electron) and exhaling carbon dioxide (as an end product).
Therefore, the correct option is A.
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Your question is incomplete, most probably the complete question is:
The process shown in the diagram produces oxygen and sugar. Which
process uses oxygen and sugar as reactants?
Chloroplast
Mitochondrion
Sugar
CO, +H,0
ATP
Heat
Respiration
A. Cellular respiration
B. Water cycle
c. Transpiration
D. Photosynthesis
a human skull is ?????
Answer:
part of the skeleton that supports the structure of face and forms a cavity from bone.
Hope it help u.
Explanation:
hope it is helpful to you
Suppose there is a gaseous mixture of nitrogen and oxygen. If the total pressure of the mixture is 480 mmHg, and the partial pressure of nitrogen is 290 mmHg, calculate the partial pressure of oxygen in the mixture using Dalton's law.
Answer:
Partial pressure of oxygen = 190 mmHg
Explanation:
From the question;
Mixture contains only nitrogen and oxygen
Total pressure of the mixture = 480 mmHg
Partial pressure of nitrogen = 290 mmHg
Dalton's law states that the pressure of a system is as a result of the sum of the partial pressures of the individual components of the mixture. This means that in this mixture;
Pressure of mixture = Partial Pressure of Nitrogen + Partial Pressure of Oxygen
480 = 290 + Partial pressure of oxygen
Partial pressure of oxygen = 480 - 290
Partial pressure of oxygen = 190 mmHg
1. Is it possible to distinguish DNA and RNA structures by using Bial’s Test? Explain.
2. What are the functions of orcinol and FeCl3 in Bial’s Test.
Answer:
yes and thats all i know
Explanation:
The energy level diagram shown below represents a fictional gas. What is the energy of a photon that would move an electron from level 2 to level 5?
A. 5.8 eV
B. 4.8 eV
C. 4.2 eV
D. 2.65 eV
The energy of a photon that would move an electron from level 2 to level 5 : B. 4.8 eV
Further explanationThe electron energy at the nth shell can be formulated:
En = -Rh / n²Rh = constant 2.179.10⁻¹⁸ J
So the electron transfer energy (ΔE)
ΔE = E final- E initial
energy at n=2(level 2) = -5.3 eV
energy at n=5(level 5) = -0.5 eV
So the energy absorbed :
[tex]\tt \Delta E=-0.5-(-5.3)=-0.5+5.3=4.8`eV[/tex]
The energy required to move an electron from level 2 to level 5 is 4.8 eV.
According to the Bohr model of the atom, an electron moves from a lower to a higher energy level when it absorbs energy. The same energy is released when the atom returns to ground state.
When an electron from level 2 to level 5, the energy of the photon required is;
ΔE = E5 - E2 = -0.5eV - (-5.3eV)
ΔE = 4.8eV
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