A different brand of iron tablet was analysed by Hitration with 0.0093 mol.L" potassium
dichromate via the reaction listed below;
Cr2O72- + 6Fe2+ + 14H+ + 2Cr3+ + 6Fe3+ + 7H20
In this experiment 4 tablets were crushed and dissolved in 200 cm3 of dilute acid. 25cm3
of this solution was used in the titration. The results of the titrations were as follows;
Titration Volume dichromate (cm)
1
33.0
2
32.05
3
32.15
4
32.10
Calculate the concentration of iron used in the titration (4 dp).
C1V1/C2V2 = n/n2
Answers
The concentration of iron used in the titration : 0.009 M
Further explanationGiven
Reaction
Cr₂O₇²⁻ + 6Fe²⁺ + 14H⁺ ⇒ 2Cr³⁺ + 6Fe³⁺ + 7H₂O
0.0093 mol/L potassium dichromate
200 cm³ of dilute acid, 25cm³ was used in the titration.
Required
the concentration of iron
Solution
Titration formula
C₁V₁n₁=C₂V₂n₂⇒ From equation : n₁=6n₂(1=Cr₂O₇, 2=Fe)
titration average : 33+32.05+32.15+32.1 / 4 = 32.325 cm³(ml)
25 cm³ of iron solution used in titration :
[tex]\tt V_1=32.325~ml\\\\V_2=25~ml\\\\C_1=0.0093~M\\\\\\\\C_1.V_1.n_2=C_2.V_2.n_1\\\\0.0093\times 32.325\times 6=C_2\times 25\times 1\\\\C_2=0.07215~M[/tex]
Dilution(25 ml from 200 ml iron solution)
[tex]\tt C_2.V_2=C_1.V_1\\\\0.007215\times 25=C_1\times 200\\\\C_1=0.009~M[/tex]
Related Questions
for each pair of compounds below , identify the one that would be expected to have more ionic character.explain you choice. (a)NaBr or HBr (b)BrCl or FCl
Answers
Answer:
a)NaBr
b)FCl
Explanation:
To identify which compound is more ionic we will calculate the electronegativity difference.
A) NaBr
Electronegativity of Na = 0.93
Electronegativity of Br = 2.96
Electronegativity difference = 2.96- 0.93 = 2.03
HBr
Electronegativity of H = 2.2
Electronegativity of Br = 2.96
Electronegativity difference = 2.96 - 2.2 = 0.76
NaBr have more ionic character because of large electronegativity difference.
B) BrCl
Electronegativity of Cl = 3.16
Electronegativity of Br = 2.96
Electronegativity difference = 3.16 - 2.96 = 0.2
FCl
Electronegativity of F = 3.98
Electronegativity of Br = 2.96
Electronegativity difference = 3.98 - 2.96 = 1.02
FCl have more ionic character because of large electronegativity difference.
How is continental crust different from oceanic crust?
A: Oceanic crust is thicker and more dense.
B: Oceanic crust is thinner and more likely to sink.
C: Continental crust is thicker and more likely to sink.
D: Continental crust is more dense and lighter.
Answers
Answer:
b
Explanation:
google lol ur welcome
B: Oceanic crust is thinner and more likely to sink.
A mirror forms an image because of which behavior of light?
refraction
reflection
diffraction
absorption
Answers
Answer: reflection
Explanation:
A mirror forms an image because of reflection of light. Therefore, the correct option is option B among all the given options.
What is light?Light is the electromagnetic radiation that is visible with the eye. Electromagnetic radiation has a very broad wavelength range, ranging from gamma rays having wavelengths shorter than around 1 1011 metre to radio waves with wavelengths measured in metres.
The spectral areas next to the visible band, infrared at one end as well as ultraviolet at the other, are often commonly referred to as light. The velocity of light in the vacuum is indeed a basic physical constant, with the current accepted value being 299,792,458 meters per second, or approximately 186,282 miles a second. A mirror forms an image because of reflection of light.
Therefore, the correct option is option B.
To learn more about light, here:
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You want to measure the volume of a gold bracelet. For this purpose, a specimen with 20 mL of water is available; when inserting the bracelet, the water level rises to 25 mL. If the density of gold is 19300 Kg/m3. What will be the mass of the bracelet?
Answers
Answer:
volume of bracelet is 5cm3
mass is 0.0965Kg
Explanation:
1ml = 1cm3
1m3 = 1000000cm3
0.000005m3
Mass = volume*density
19300 Kg/m3 * 0.000005m3 = 0.0965Kg
What ratio of concentration of ammonia and ammonium chloride should be mixed to
prepare a buffer solution of pOH 5? (Kb for NH3 =1.8 x 10-4)
Answers
The ratio of concentration of ammonia and ammonium chloride : 0.05
Further explanationGiven
pOH=5
Kb for NH3 =1.8 x 10-4
Required
The ratio of concentration of ammonia (NH₃) and ammonium chloride(NH₄Cl)
Solution
Solutions containing ammonia and its salt: ammonium chloride are called alkaline buffers
Can be formulated : ( for the same of the volume, mol=concentration)
[tex]\tt \displaystyle [OH-]=Kb\times\frac{weak\:base\:mole}{salt\:mole\times valence}[/tex]
pOH=-log [OH⁻]
pOH=5⇒[OH⁻]=10⁻⁵
Valence for NH₄Cl = 1, so the concentration ratio :
[tex]\tt 10^{-5}=1.8\times 10^{-4}\times \dfrac{[~NH_3]}{[NH_4Cl]}\\\\0.05=\dfrac{[~NH_3]}{[NH_4Cl]}[/tex]
True or False: All metals have high melting points.
Answers
Answer:
True. All metals have a melting point when it reaches a certain degree of temperature
Explanation:
Type the correct answer in the box. Express your answer to three significant figures.
A balloon is filled with 0.250 mole of air at 35°C. If the volume of the balloon is 6.23 liters, what is the absolute pressure of the air in the balloon?
Answers
Answer:
102.807 kPa
Explanation:
There are some assumptions to be made in the answer. The air inside the balloon acts as an ideal gas at a given temperature conditions.
Using the combined ideal gas equation.
P= absolute pressure of the air inside the balloon.
V= volume of air inside the balloon (6.23 L= 6.23 * 10⁻³ m³)
n= moles of gas(air). (0.250 mol)
R= Universal gas constant ( 8.314 J / mol·K)
T= Temperature in Kelvin
T= 35 + 273.15 = 308.15 K
P= 102.807 * 10³ Pa
P= 102.807 kPa
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
Answers
1) Compounds Y and Z both have the formula C9H18.
Both Y and Z react with one molar equivalent of hydrogen in the presence of a palladium catalyst to form 2-methyloctane.
The heat of hydrogenation of Y is less than that of Z.
Y and Z each undergo hydroboration/oxidation to give a primary alcohol (OH attached to a primary carbon).
What is the structure of Y?
2) Compound X has the formula C8H12.
X reacts with two molar equivalents of hydrogen in the presence of a palladium catalyst to form cyclooctane.
Treatment of X with ozone followed by zinc in aqueous acid gives two molar equivalents of the same dialdehyde.
What is the structure of X
Answers
Answer:
See explanation and images attached
Explanation:
We know that the cis isomer has more heat of hydrogenation since it is less stable than the trans isomer. Since the hydrogenation of both compounds yields the same product and the hydroboration/oxidation both give a primary alcohol, they are geometric isomers and Y is the trans isomer (Image 2).
For the compound C8H12, the compound in question must be 1,5- cyclooctadiene since two moles of the same aldehyde was obtained after ozonolysis and reaction with two equivalents of hydrogen gives cyclooctane (Image 1).
Name the following hydrocarbon:
CH3CH2CH2CH2F
A. 4-fluorobutane
B. 2-fluorobutane
C. 1-fluorobutane
D. 1-fluoropentane
Answers
Answer:
The correct answer is (C)
Which is "1-fluorobutane"
Explanation:
Hope this helped if so please leave a "Rating" and "Like" and MARK me Brainliest if it was the BEST answer! THANKS! :)
The name of the hydrocarbon CH3CH2CH2CH2F is 1-fluorobutane.
In naming organic hydrocarbons, we count the number of the parent chain family. Here, we have an alkane with 4 carbons, which means that the parent chain is a family of alkane. The fourth compound in the family of an alkane is butane.
Afterwards, we will determine if there is any substituent attached to any of the carbon atoms in the chain and rank them in a way such that we have the lowest possible number.
Here, the fluorine is attached to the first carbon atom. So, it becomes 1-fluorobutane.
Learn more about the naming of hydrocarbons here:
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At which point is crust neither created nor destroyed?
island chain
mid-ocean ridge
divergent boundary
transform boundary
Answers
Answer:
transform battery
Explanation:
Answer: D. Transform Boundary
Explanation: I did the test.
What 3 particles make up an atom and what is their electrical charge?
Answers
2. Proton- positive charge
3. Neutron- neutral charge
electrons having a negative charge .
neutrons possessing no net charge.
The pressure of a sample of argon gas was increased from 3.89 atm to 8.73 atm at constant temperature. If the final volume of the argon sample was 18.4 L, what was the initial volume of the argon sample? Assume ideal behavior.
Answers
Answer:
41.29 LExplanation:
The initial volume can be found by using the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
Since we are finding the initial volume
[tex]V_1 = \frac{P_2V_2}{P_1} \\[/tex]
From the question we have
[tex]V_1 = \frac{8.73 \times 18.4}{3.89} = \frac{160.632}{3.89} \\ = 41.293573...[/tex]
We have the final answer as
41.29 LHope this helps you
when coal goes through combustion it releases nitrogen and sulpur into the air in the form of what
Answers
Answer:
Over time, the plant matter transforms from moist, low-carbon peat, to coal, All types of coal also contain sulfur, which, when burned, releases toxic air pollution. Sulfur All this coal comes from mines, which are either underground or run on diesel—a major source of air toxins, nitrogen oxide, and soot.
butane
methane
ethane
propane
Answers
Given
the structure of the alkanes
Required
match the image to the name
Solution
Alkanes are saturated hydrocarbons with all of the carbon bonds being single bonds
General formula:
[tex]\large {\boxed {\bold {C_nH_2n + 2}}}[/tex]
If we look at the picture, we define the black atom as Carbon and the branch is Hydrogen
To determine the name of the alkane, all we have to do is count the number of Carbon atoms
Butane : C₄H₁₀ : 4 C atoms
Methane : CH₄ : 1 C atom
Ethane : C₂H₆ : 2 C atoms
Propane : C₃H₈ : 3 C atoms
Show the calculation of the molality of a solution made by dissolving 15.9 grams of Ca3(PO4)2 in 400 grams of water.
Answers
The molality of a solution : 0.128 m
Further explanationGiven
15.9 g of Ca3(PO4)2 in 400 grams of water.
Required
The molality
Solution
molality = mol solute / kg solvent
solute= Ca3(PO4)2(MW=Molecular Weight: 310.2 g/mol)
mol solute :
[tex]\tt \dfrac{15.9}{310.2}=0.0512[/tex]
The molality :
[tex]\tt \dfrac{0.0512}{0.4~kg}=0.128~m[/tex]
why is it important to prepare for disaster? what are the things you need to prepare?
Answers
Explanation:
The reason why it is important to prepare for an disaster is because Being prepared can reduce fear, anxiety, and losses that accompany disasters. People also can reduce the impact of disasters (flood proofing, elevating a home or moving a home out of one's harm's way, and securing items that could shake loose in an earthquake) and sometimes avoid the danger completely.
The things you need to prepare for an disaster is
WaterFoodClothing Money if neededFlash lightBatteriesFirst aid kitYou can even need an radio( to keep updated).What will happen to the following equilibrium if Cl2
was removed ?
4HCI(9) + O2(9) = 2012(9) + 2H20(9)
Answers
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:
the initial internal energy of a system is 43.5kj. it absorbs 8.3kj of heat while performing 3.5kj of work on the surroundings. what is its final internal energy?
Shows works to help me understand what I did wrong.
Answers
Answer:
[tex]U_2=48.3kJ[/tex]
Explanation:
Hello!
In this case, since the fist law of thermodynamics helps us to understand how the change in internal energy is defined in terms of the head added to the system and the work done by the system:
[tex]Q+W=\Delta U[/tex]
In such a way, since 8.3 kJ of heat are absorbed by the system, 3.5 kJ are done by the system and the initial internal energy is 43.5 kJ, the final internal energy turns out:
[tex]U_2=U_1+Q-W\\\\U_2=43.5kJ+8.3kJ+3.5kJ\\\\U_2=48.3kJ[/tex]
Best regards!
How much heat is necessary to vaporize 685 g of H20 at 100°C? The heat of vaporization
of H2O is 540 cal/g.
0 370,000 cal
O 1.22 x 103 cal
O 88,400 cal
01.27 kcal
h
Question 8
3.33 pts
Answers
Answer:
370,000 cal
Explanation:
Step 1: Given data
Mass of water (m): 685 gHeat of vaporization of water (ΔH°vap): 540 cal/gStep 2: Calculate the heat necessary to vaporize 685 g of water
Vaporization is the process in which a liquid converts to a gas, at a constant temperature. The heat required (Q) is:
Q = ΔH°vap × m
Q = 540 cal/g × 685 g
Q = 3.70 × 10⁵ cal
Why is light a wave?
Answers
Answer:
an electromagnetic wave
Explanation:
ASAP PLZ HELP I WILL MARK BRAINLIEST Based on the diagram, what can you conclude about the pole of the magnet? O It is a south pole because the field lines spread out from this end. O It is a north pole because the field lines spread out from this end, O It is a south pole because the field lines enter the magnet at this end. O It is a north pole because the field lines enter the magnet at this end.
Answers
Answer:C
Explanation:I took the test
Answer:
It is a south pole because the field lines enter the magnet at this end.
Explanation:
5 A snowball sits at the top of the hill. Which of the following changes will increase the kinetic energy of the snowball? A Additional snow falls on the snowball, increasing its mass. B The snowball is pushed and rolls down the hill, gaining speed. The weather warms and the snowball melts, decreasing its mass. D The snowball is moved and now sits on a hill that is higher.
Answers
Answer:
B
Explanation:
it is B because in order to have kinetic energy the object has to be in motion, because if it wasnt in motion and sitting on the hill then it has potentail energy, hope this helps
The Lewis diagram for BH2 is:
[H-B-H]-
The electron- pair geometry around the B atom in BH2 is:__________.
There are______lone pair(s) around the central atom, so the geometry of BH2 is________ .
Answers
Answer:
Electron pair geometry- trigonal planar
There is one lone pair around the boron atom
The geometry of BH2 is bent
Explanation:
The valence shell electron pair repulsion theory offers a frame work for determining the shape of molecules based on the number of electron pairs of the valence shell of the central atom in the molecule.
In BH2-, the central atom is boron. There is a lone pair on boron. Owing to the lone pair on boron, the molecular geometry of BH2 is bent.
The geometry of the electron pair around the Boron atom in [tex]BH_2[/tex] is called the trigonal planar. In this case, there is a pair of isolated electrons around Boron, which is the central atom, allowing the [tex]BH2[/tex] molecule to have a folded geometry.
We can arrive at this answer because:
Boron is an element that has three electrons in its valence layer.With this, we can find out that it can make three covalent bonds or donate these electrons to achieve chemical stability.In the case of the [tex]BH_2[/tex] molecule, boron forms covalent bonds with Hydrogen.These bonds allow the Hydrogens to be positioned on either side of the Boron molecule, forcing a pair of their electrons to focus on the center of that molecule, until it is attracted to the extremities.This allows for a folded geometry around the molecule, allowing Boron to be an exception to the octet rule and achieve stability with 5 electrons in the valence layer.
More information:
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what does the phrase sea of electrons describe?? please help
Answers
Answer: Metallic Bonding.In metallic bonds, the valence electrons from the s and p orbitals of the interacting metal atoms delocalize. That is to say, instead of orbiting their respective metal atoms, they form a “sea” of electrons that surrounds the positively charged atomic nuclei of the interacting metal ions.
Explanation:
How many moles are present in 2.126 g of H2O2 ?
Answers
Answer:
molecular weight of H2O2 or grams. This compound is also known as Hydrogen Peroxide. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles H2O2, or 34.01468 grams.
1 grams H2O2 is equal to 0.029399071224542 mole.
1 grams H2O2 to mol = 0.0294 mol
10 grams H2O2 to mol = 0.29399 mol
20 grams H2O2 to mol = 0.58798 mol
30 grams H2O2 to mol = 0.88197 mol
40 grams H2O2 to mol = 1.17596 mol
50 grams H2O2 to mol = 1.46995 mol
100 grams H2O2 to mol = 2.93991 mol
200 grams H2O2 to mol = 5.87981 mol
There are 0.0625mol in 2.126 g of H2O2.
HOW TO CALCULATE MOLES:
The number of moles of a substance can be calculated by dividing the mass of the substance by its molar mass. That is;no. of moles (mol) = mass (g) ÷ molar mass (g/mol)According to this question, 2.126 g of H2O2 were given. The number of moles of H2O2 can be calculated as follows:Molar mass of H2O2 = 1(2) + 16(2)= 2 + 32
= 34g/mol
no. of moles = 2.126g ÷ 34g/molno. of moles = 0.0625molTherefore, there are 0.0625mol in 2.126 g of H2O2..Learn more at: https://brainly.com/question/21085277?referrer=searchResults
3Ba2+(aq) + 2PO43−(aq) ⇌ Ba3⎛⎝PO4⎞⎠2(s). Is Kc> 1, < 1, or ≈ 1?
Answers
Answer:
Kc < 1
Explanation:
Since the product formed is in solid state, from law of mass action.
Kc = 0
[Ba2+]³[PO4³-]²
hence Kc is 0
Create an atom diagram using the Bohr model. Directions Choose three elements from the following list. Use a periodic table to determine the number of protons, neutrons, and electrons. Draw a diagram of each element you have selected. Use a separate piece of paper for each element. Be sure your drawing is neat, legible, and accurate. Use this data table to record information about each element. Element #1 Element #2 Element #3 Element #4
Answers
Answer:
Explanation:
proposed an early model of the atom as a central nucleus containing protons and neutrons being orbited by electrons in shells. As previously discussed, there is a connection between the number of protons in an element, the atomic number that distinguishes one element from another, and the number of electrons it has. In all electrically-neutral atoms, the number of electrons is the same as the number of protons. Each element, when electrically neutral, has a number of electrons equal to its atomic number.
Answer:
You can check diagram with number of proton neutron and electrons
Explanation:
In a molecule of calcium sulfide, calcium has two valence electron bonds, and a sulfur atom has six valence electrons. How many lone pairs of electrons are present in the Lewis structure of calcium sulfide?
A. one
B. two
C. three
D. four
E. none
Also, state why.
Answers
Answer:
E
because it forms the ionic bond but not covalent.
In science why is it important to explain why the evidence supports your claim?