Which of these half-reactions represents reduction?
I. Fe2+ → Fe3+
II. Cr2O72- → Cr3+
III. MnO4- → Mn2+

Answers

Answer 1

Answer: The half-reactions represents reduction are as follows.

[tex]Cr_{2}O^{2-}_{7} \rightarrow Cr^{3+}[/tex][tex]MnO^{-}_{4} \rightarrow Mn^{2+}[/tex]

Explanation:

A half-reaction where addition of electrons take place or a reaction where decrease in oxidation state of an element  takes place is called reduction-half reaction.

For example, the oxidation state of Cr in [tex]Cr_{2}O^{2-}_{7}[/tex] is +6 which is getting converted into +3, that is, decrease in oxidation state is taking place as follows.

[tex]Cr_{2}O^{2-}_{7} + 3 e^{-} \rightarrow Cr^{3+}[/tex]

Similarly, oxidation state of Mn in [tex]MnO^{-}_{4}[/tex] is +7 which is getting converted into +2, that is, decrease in oxidation state is taking place as follows.

[tex]MnO^{2-}_{4} + 5 e^{-} \rightarrow Mn^{2+}[/tex]

Thus, we can conclude that half-reactions represents reduction are as follows.

[tex]Cr_{2}O^{2-}_{7} \rightarrow Cr^{3+}[/tex][tex]MnO^{-}_{4} \rightarrow Mn^{2+}[/tex]

Related Questions


How many atoms in total are there in 7.35 mol of magnesium oxide (MgO)
molecules?

Answers

Answer:

4.42 x 10^24

Explanation:

A gas at STP occupies 0.055 L of space. If the pressure changes to
2.8 atm and the temperature increases to 195°C, what is the new
volume?

Answers

Answer:

0.034 L

Explanation:

From the question given above, the following data were obtained:

Initial volume (V₁) = 0.055 L

Initial pressure (P₁) = stp = 1 atm

Initial temperature (T₁) = stp = 273 K

Final pressure (P₂) = 2.8 atm

Final temperature (T₂) = 195 °C = 195 °C + 273 = 468 K

Final volume (V₂) =?

The final volume of the gas can be obtained as follow:

P₁V₁ / T₁ = P₂V₂ / T₂

1 × 0.055 / 273 = 2.8 × V₂ / 468

0.055 / 273 = 2.8 × V₂ / 468

Cross multiply

273 × 2.8 × V₂ = 0.055 × 468

764.4 × V₂ = 25.74

Divide both side by 764.4

V₂ = 25.74 / 764.4

V₂ = 0.034 L

Therefore, the new volume of the gas is 0.034 L.

Explain why the coefficients on the left side of the equation don’t necessarily equal the coefficients on the right side of the equation. Is this possible if mass is being conserved?

Answers

Answer:

Explanation:

Short answer: Yes.

The coefficients may not be conserved, but mass always has to be. Take this equation as an example

2 Mg3P2 ===>   6Mg + P4

There is a 2 on the left side and 6 and 1 on the right. I hope you mean that the coefficient 2 is not equal to 7.

But let's look a little closer. You have to look at the molecular structure of the left and right side.

2Mg3P2 has 6 Mgs and 4 Ps on the left side.

6Mg is on the right. They are free standing.

P4    has 1 molecule consisting of 4 Ps.

Everything balances.

This is a terrific question to be asking. You need to understand the internal balance numbers vs the molecular ones on the out side.

That sounds like a bit of gobbledygook and it takes a bit of study.

2 Mg3P2 means that Mg3P2 is written twice.

Mg3P2 ==> "3 Mg2+   +  2P3+   and there is another one written the same way.

Mg3P2 ==> "3 Mg2+   +  2P3+  

I need help Type th temperature (in Kelvin) in the left column and the volumes in the right column, being sure to keep pairs of data together. then click resize window to fit data.

the data appears to be
linear
quadratic
exponential
logarithmic​

Answers

Answer:

Linear

Explanation:

a. acidic
b. basic
; neutral
d. will not be affected
Find the molarity of 10% NaOH.[MOE 2003
a. 1.5
b! 2.5
c. 4
d. 0.4
10 ml of 2.5 N NaOH is mixed with 20 ml of
N HCI. The mixture is diluted to 100 ml. WI
is the nature of mixture?
IMOF 20​

Answers

1. You didn't post the question to Number 1.

2.

10% means There's 10g in 100ml of this solution.

This is the weight/volume(w/v) expression of concentration.

So

We have Mass =10g

volume =100ml

Molarity = Moles of solute/volume of solution(in LITRES)

Moles=Mass/Molar mass

Molar mass of NaOH=40g/mol

Mole=10/40

=0.25mole

Volume =100ml =0.1Litres

MOLARITY=0.25/0.1 =

=2.5M

OPTION B.

3. NOTE: THE MOLARITY AND NORMALITY OF NAOH AND HCL ARE THE SAME(This doesn't happen for all compounds tho)

So We can take 2.5N(Normality) of NaOH to be 2.5M(Molarity) NaOH

I think you forgot to write the Normality of the second one. I'll take it to be 1N. Maybe you can then Input supposed value when you're solving on your own

So

1N HCl is same as 1M HCL

We were given their respective volumes

2.5M NaOH can also be written as 2.5mole/volume(in Liters)

The volume of NaOH =10ml or 0.01L

Moles = 2.5mole/L x 0.01L

You notice that Liters on top and bottom cancels out... leaving the moles

So

Mole=0.01x2.5 = 0.025moles of NaOH

we're gonna do the same for 1N HCl in 20ml(0.02L)

So

Mole = 1 x 0.02 =0.02moles

Total Mole = 0.02 + 0.025 =0.045moles

The Final Volume is 100ml as stated in the question. It was diluted to 100ml or 0.1L

So

Final Concentration In Molarity

= Total Moles/Volume in L

=0.045/0.1

=0.45M.

2) A 0.77 mg sample of nitrogen gas reacts with chlorine gas to form 6.61 mg of a nitrogen
chloride compound. What is the empirical formula of the nitrogen chloride compound?

Answers

Answer:

NCl₃

Explanation:

From the question given above, the following data were obtained:

Mass of nitrogen (N) = 0.77 mg

Mass of chlorine (Cl) = 6.61 mg

Empirical formula =?

The empirical formula of the compound can be obtained as follow:

N = 0.77 mg

Cl = 6.61 mg

Divide by their molar mass

N = 0.77 / 14 = 0.055

Cl = 6.61 / 35.5 = 0.186

Divide by the smallest

N = 0.055 / 0.055 = 1

Cl = 0.186 /0.055 = 3

Therefore, the empirical formula of the compound is NCl₃

The area of a telescope lens is 6507 x 10^3 mm^2. What is the area in square feet, enter your answer in scientific notation. If it takes a technician 51.6 s to polish 1.68 x 10^2 mm^2 how long does it take her to polish the entire lens ?

Answers

Answer:  the area of the telescope lens is \textit{0,08507 ft}

Explanation: Happy I could help!

C. Balance these fossil-fuel combustion reactions. (1 point)

Answers

The question is incomplete. The complete question is :

C. Balance these fossil-fuel combustion reactions. (1 point)

C8H18(g) + 12.5O2(g) →    ____CO2(g) + 9H2O(g) + heat

CH4(g) + ____O2(g) →     ____CO2(g) + ____H2O(g) + heat

C3H8(g) + ____O2(g) →    ____CO2(g) + ____H2O(g) + heat

C6H6(g) + ____O2(g)  →   ____CO2(g) + ____H2O(g) + heat

Solution :

C8H18(g) + 12.5O2(g) →    __8__CO2(g) + 9H2O(g) + heat

When 1 part of octane reacts with 12.5 parts of oxygen, it gives 8 parts of carbon dioxide and 9 parts of water along with liberation of energy.

CH4(g) + __2__O2(g) →     __1__CO2(g) + __2__H2O(g) + heat

When 1 part of methane reacts with 2 parts of oxygen, it gives 1 part of carbon dioxide and 2 parts of water along with liberation of energy.

C3H8(g) + __5__O2(g) →    __3__CO2(g) + __4__H2O(g) + heat

When 1 part of propane reacts with 5 parts of oxygen, it gives 3 part of carbon dioxide and 4 parts of water along with liberation of energy.

C6H6(g) + __1/2__O2(g)  →   __6__CO2(g) + __3__H2O(g) + heat

When 1 part of propane reacts with 1/2 parts of oxygen, it gives 6 part of carbon dioxide and 3 parts of water along with liberation of energy.

Explain why this combination of compounds can or cannot make a buffer solution. Hint: apply definition of a buffer, mechanism of its action and consider whether the compound is acid (weak/strong) or base (weak/strong). HF (0.2 mol) and NaOH (0.1 mol)

Answers

Answer:

This combination can make a buffer

Explanation:

A buffer is defined as an aqueous mixture of a weak acid and its conjugate base, or vice versa.

In the problem, HF is a weak acid, and its conjugate base is F⁻.

When NaOH reacts with HF, F⁻, Na⁺ and H₂O are produced as follows:

NaOH + HF → F⁻ + Na⁺ + H₂O

As there are initially 0.2mol of HF and 0.1mol NaOH, after the reaction you will have:

0.1mol HF and 0.1mol F⁻. As both, the weak acic and the conjugate base are present:

This combination can make a buffer

HELP! ASAP! Iron (Fe) and copper (II) chloride (CuCl2) combine to form iron (III) chloride (FeCl3) and copper (Cu). If you start with 155,8 grams of
iron (Fe), how many grams of copper (Cu) will be produced?
2Fe + 3CuCl2 à 2FeCl3 + 3Cu

Answers

Answer: 30.978

Explanation:

From the equation 2 moles of Fe will result in 3 moles copper

so .325 moles Fe will result in .4875 moles Cu

Cu weights 63.546 gm per mole

.4875 moles * 63.546 gm / mole = 30.978 gm of Cu

Question 1
Where does photosynthesis happen in a plant cell?
O Cell membrane
O Cell wall
O Chloroplast
O Mitochondria

Answers

Answer:

Chloroplast

Explanation:

Photosynthesis happens in chloroplast of plants. Mitochondira is where the cellular respiration happens.


If ammonium phosphate reacts with sodium chloride in aqueous solution, what are the products?

Answers

Answer:

[tex](NH_4)_3PO_4(aq)+3NaCl(aq)\rightarrow 3NH_4Cl(aq)+Na_3PO_4(aq)[/tex]

Explanation:

Hello there!

In this case, according to the given information, we can set up the appropriate chemical equation when ammonium phosphate reacts with sodium chloride in aqueous solution:

[tex](NH_4)_3PO_4(aq)+NaCl(aq)\rightarrow NH_4Cl(aq)+Na_3PO_4(aq)[/tex]

Which stands for a double replacement reaction, whereby ammonium changes phosphate to chloride and sodium changes chloride to phosphate on the products side. In addition, we can balance the aforementioned equation as shown below:

[tex](NH_4)_3PO_4(aq)+3NaCl(aq)\rightarrow 3NH_4Cl(aq)+Na_3PO_4(aq)[/tex]

Regards!

how do the hydrosphere and atmosphere interact? give an example

Answers

Answer:

Evaporation

Explanation:

Water in the ocean, rivers, lakes, etc. is part of the hydrosphere, and when that water evaporates it enters the atmosphere

What do all fossil fuels have in common?
O A. They are all liquids.
OB. They all contain crude oil.
O C. They all produce nitrogen as a combustion product.
O D. They are all nonrenewable energy sources.

Answers

Answer:

Your answer would be D, they are all non-renewable energy sources. Hope this helps!

Answer:

D. They are all nonrenewable energy sources.

Brainiest and 10 Points
Which has a HIGHER frequency?
A. Visible
B. Ultraviolet

Answers

Answer:

B. Ultraviolet

Explanation:

UV has a higher frequency and shorter wavelength than visible light

When an acetic acid solution is titrated with sodium hydroxide, the slope of the titration curve (pH versus volume of NaOH added) increases when sodium hydroxide is first added. This change shows that ________

Answers

Answer:

When an acetic acid solution is titrated with sodium hydroxide, the slope of the titration curve (pH versus volume of NaOH added) increases when sodium hydroxide is first added. This change shows that acetic acid is being converted to sodium acetate.

Explanation:

ABOUT TITRATION - Titration is a chemical analysis method for determining the amount of a constituent in a sample by adding an exact known quantity of another substance to the measured sample with which the desired constituent reacts in a specific, known proportion. A burette, which is essentially a long, graduated measuring tube with a stopcock and a delivery tube at the bottom end, is used to gradually administer a standard solution of titrating reagent, or titrant.

It is feasible to identify a good visual color indicator for many titration processes that will signify the end point at, or very near to, the equivalence point.

Acid-base titrations, precipitation titrations, complex-formation titrations, and oxidation-reduction (redox) titrations are examples of such titrations, which are categorised according to the nature of the chemical reaction that occurs between the sample and the titrant.

Titrations of metal ions with the reagent disodium ethylenediaminetetraacetate are the most important titrations based on complex-formation processes (a salt of edetic acid, or EDTA).

Hence , the answer is that acetic acid is converted into sodium acetate.

Pure magnesium metal is often found as ribbons and can easily burn in the presence of oxygen. When 3.31 g of magnesium ribbon burns with 8.45 g of oxygen, a bright, white light and a white, powdery product are formed. Enter the balanced chemical equation for this reaction. Be sure to include all physical states.

Answers

Answer:

2Mg(s) + O2(g) ----->2MgO(s)

Explanation:

In writing a balanced chemical reaction equation, the rule of thumb is that the number of atoms of each element on the reactant side must be the same as the number of atoms of the same elements on the products side.

Hence for the reaction of magnesium and oxygen shown below;

2Mg(s) + O2(g) ----->2MgO(s)

We notice that there are two atoms each of magnesium and oxygen on both sides of the reaction equation hence the equation is balanced.

How many grams of ammonium fluoride, , must be dissolved to prepare 300. mL of a 0.234 M aqueous solution of the salt

Answers

Answer:

24.24 g

Explanation:

First we calculate how many moles are there in 300 mL of a 0.234 M solution, using the definition of molarity:

Molarity = moles / liters

Converting 300 mL to L ⇒ 300 mL / 1000 = 0.300 L

0.234 M = moles / 0.300 Lmoles = 0.78 moles

Then we convert 0.78 moles of NH₄F into grams, using its molar mass:

0.78 mol * 31.073 g/mol = 24.24 g

In Atom, what is a heavier sub-atomic particle than the others and explain why​

Answers

The nucleons are havier in sub atomic particle like neutrons and protons.

fun fact i read in a book even 1cm³ of nucleons are around 2 million Kg which you can't pick up by hand even by machines like buldozer.

Which type of molecule is shown below?

A. Cyclic alkene
B. Alkene
C. Alkyne
D. Cyclic alkane

Answers

Answer:

D. Cyclic alkane

Explanation: there is no double or triple bond

The type of molecule that is shown below in the picture is a cyclic alkane. The correct option is D.

What is the cyclic alkane?

This is the compound that contain hydrogen and carbon bond. They are mono cyclic saturated hydrocarbons.

These are the atoms that replace the hydrogen atom in an organic compound.

Thus, the correct option is D. Cyclic alkane.

Learn more about cyclic alkane

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A 0.200 M solution of a week acid, HA, is 9.4% ionized. The molar concentration of H+ is 0.0188 M. the Acid-dissociation constant, Ka, for HA is...?​

Answers

We are given:

Initial concentration of HA: 0.200 Molar

The acid is 9.4% ionized

Dissociation constant (α) = (Percent Ionized) / 100 = 0.094

Molar concentration of H+ = 0.0188

Let's Chill! (making the ICE box):

Reaction:       HA         ⇄       H⁺      +      A⁻

Initial:           0.200M               -                -

Equilibrium: 0.200(1-α)      0.200α       0.200α

while we're here, let's confirm the given equilibrium concentration of H⁺ ions

from the table here, we can see that the equilibrium concentration of H⁺ ions is 0.200α, we know that α = 0.094

[H⁺] = 0.200α = 0.200 * 0.094 = 0.0188 M

which means that we're on the right track

We're basically scientists at this point (finding the dissociation constant):

Acid dissociation is nothing but the equilibrium constant, but for the dissociation of Acids

From the reaction above, we can write the equation of the acid dissociation constant:

Ka = [H⁺][A⁻] / [HA]

now, let's take the values from the 'equilibrium' row of the ice box the plug those in this equation

Ka = (0.200α)(0.200α) / [0.200(1-α)]

Ka = (0.200α)²/[0.200(1-α)]

plugging the value of α

Ka = (0.200*0.094)² / [0.200(0.906)]

Ka = (0.0188)² / 0.1812

Ka = 1.95 * 10⁻³

Observe: Click Reset (). The electrons in the outermost orbit, called valence electrons, help to create chemical bonds. Create a lithium atom (3 protons, 4 neutrons, 3 electrons). How many valence electrons are in a neutral lithium atom?

Answers

Answer:

There is one valence electron in a neutral lithium atom.

Explanation:

The number of valence electrons in a neutral lithium atom is equal to one.

What is a valence electron?

Valence electrons can be described as the electrons filling the outermost shell of an atom while the electrons in the inner shell of an atom are known as core electrons. Lewis structures are used to determine the number of valence electrons and know the types of chemical bonds.

Valence electrons of an atom can be filled in the same or different orbitals and these electrons are responsible for the interaction between atoms and cause the formation of chemical bonds.

Only electrons occupied in the outermost shell can participate in the formation of a bond or a molecule and are responsible for the reactivity of the element.

The number of electrons in the neutral atom of lithium is 3. There is only one electron present on the outermost shell 2s-orbital.

Learn more about valence electrons, here:

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Identify the true statement(s). There may be one answer or more than one answer.FADH2 is a reducing agent. FADH2 is an oxidizing agent. NADH is an oxidizing agent. NADPH is a reducing agent. FAD is an oxidizing agent.

Answers

Answer:

FADH2 is a reducing agent.

FAD is an oxidizing agent.

Explanation:

The full form of FAD is flavin adenine dinucleotide. It is mainly a redox-active coenzyme which is associated with the different proteins and is involved with the enzymatic reactions in the metabolism.

FAD is obtained by donating or accepting electrons.

In the citric acid cycle,

succinate + FAD → fumarate + [tex]$FADH_2$[/tex]

Thus we see that FAD is an oxidizing agent while [tex]$FADH_2$[/tex] is a reducing agent.      

Difference between brain and spinal cord
Pls help

Answers

They are both part of the nervous system but the brain is housed inside the skull and it controls most of the activities of the body. In higher organisms such as humans and other vertebrates, it is the centre of learning. Then the spinal cord is a tube-like structure that begins from the end of the brain and ends at the bottom of the backbone. The spinal cord is made up of nerves that carry information between the brain and the rest of the body.
The brain is housed inside the cranium and the spinal cord is enclosed inside the vertebral column

What transition energy corresponds to an absorption line at 460 nm?
A. 6.52 x 10-19 J
B. 4.32 x 10-19 J
C. 4.45 x 10-19 J

D. 2.31 x 10-19 J

Answers

The answer is b I think I hope it right

Answer:

B. 4.32 x 10-19 J is correct via a p e x

Explanation:

You start with 0.1 L of a 5.00 M solution, and you plan to dilute it to make a
solution with a concentration of 0.625 M. How much water did you add to
the container?
a) 800ML
b) 100ml
c)700ml
d)750ml

Answers

You add 100 ml of water to the container

As the diagram model the processo se reproduction lomon) formand change formation Sexual reproduction results in a child that is different from its parents because

A. the child receives all of is genetic information from its mother

B. the child produces its own genetic information once it is formed

C. the child receives half of is genetic information from each parent

D. the child receives all of it's genetic information from it's father there ​

Answers

Answer:

The answer is C. the child receives half of is genetic information from each parent

Explanation:

hope this helps enjoy

It took 10.40 mL of a NaOH solution to neutralize 0.307 g of KHP. What is the molarity of the NaOH solution

Answers

Answer:

0.144 M

Explanation:

First we convert 0.307 g of KHP (potassium hydrogen phthalate, KHC₈H₄O₄) into moles, using its molar mass:

0.307 g ÷ 204.22 g/mol = 0.0015 mol KHP

1 mol of KHP reacts with 1 mol of NaOH, that means that in 10.40 mL of the NaOH solution there were 0.0015 moles of NaOH.

Now we calculate the molarity of the NaOH solution:

10.40 mL / 1000 = 0.0104 LMolarity = 0.0015 mol / 0.0104 L = 0.144 M

help please hurry lots of points

Answers

I think ionic hope it helps

a gas tank contains 15 moles of oxygen and 20 moles helium what is apertial pressure of helium in this mixture​

Answers

Answer:

D0wnload Phot0Math......................

Explanation:

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