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]1. Phosphorous reacts with bromine to form phosphorous tribromide. If 35.0 grams of bromine
reacted and 27.9 grams of phosphorous tribromide are actually formed.
what is the percent yield of phosphorous tribromide (PBr3)?
2 P + 3 Br2 ---> 2 PBr3
(Note that the molar masses: P=30.97g, Br = 79.90g) Show your steps
*
Please help me
Answer:
70.6 %
Explanation:
First step, we define the reaction:
2P + 3Br₂ → 2PBr₃
We determine the moles of reactant:
35 g . 1mol / 159.8 g = 0.219 moles
We assume, the P is in excess, so the bromine is the limiting reagent.
3 moles of Br₂ can produce 2 moles of phophorous tribromide
Then, 0.219 moles may produce (0.219 . 2) /3 = 0.146 moles of PBr₃
We convert moles to mass:
0.146 mol . 270.67 g /mol = 39.5 g
That's the 100 % yield reaction, also called theoretical yield. The way to determine the % yield is:
(Yield produced / Thoeretical yield) . 100
(27.9 / 39.5) . 100 = 70.6 %
meaning of alchol in one word
You want to decaffeinate your coffee by extracting the caffeine outwith dichloromethane. It's too late to extract the caffeinefrom the coffee beans because you've already brewed yourself a 200mL cup of coffee. Your particular brand of coffee contains100 mg of caffeine in that 200mL cup. The partitioncoefficient of caffeine in dichloromethane/water is 9.0.
How much caffeine would still be in your 200 mL if you did:
A. One extraction using 200 mL o fdichloro methane
B. Two extractions using 100 mL of dichloro methane each.
Solution :
The partition coefficient
[tex]$k_d= \frac{\text{(mass of caffeine in }CH_2Cl_2 / \text{volume of }CH_2Cl_2)}{\text{(mass of caffeine in water/ volume of water)}}$[/tex]
= 9.0
A). 1 x 200 mL extraction
Let m be the mass of caffeine in water
Mass of caffeine in [tex]$CH_2Cl_2$[/tex] = 100 - m
∴ [tex]$\frac{(100-m)/200}{m/200}=9$[/tex]
[tex]$\frac{100-m}{m}=9$[/tex]
[tex]$10 \ m = 100$[/tex]
[tex]$m=\frac{100}{10}$[/tex]
= 10
Therefore, the mass remaining in the coffee is m = 10 mg
B). 2 x 100 mL extraction
First extraction :
Let [tex]$m_1$[/tex] be the mass of the caffeine in water.
Mass of caffeine in [tex]$CH_2Cl_2$[/tex] = 100 - m
∴ [tex]$\frac{(100-m_1)/100}{m_1/200}=9$[/tex]
[tex]$\frac{100-m_1}{m_1}=9$[/tex]
[tex]$5.5 \ m_1 = 100$[/tex]
[tex]$m_1=\frac{100}{5.5}$[/tex]
= 18.18
Mass remaining in the coffee after the 1st extraction [tex]$m_1$[/tex] = 18.18 mg
Second extraction:
Let [tex]$m_2$[/tex] be the mass of the caffeine in water.
Mass of caffeine in [tex]$CH_2Cl_2$[/tex] = 18.18 - [tex]$m_2$[/tex]
∴ [tex]$\frac{(18.18-m_2)/100}{m_2/200}=9$[/tex]
[tex]$\frac{18.18-m_2}{m_2}=9$[/tex]
[tex]$5.5 \ m_2 = 18.18$[/tex]
[tex]$m_1=\frac{18.18}{5.5}$[/tex]
= 3.3
Mass remaining in the coffee after the 1st extraction [tex]$m_2$[/tex] = 3.3 mg
When a mixture of oxygen and hydrogen is ignited in a test tube, the
reaction shown occurs. What happens to the total mass of the contents of
the test tube?
Answer:
follow me and pm and I answer your question
A plot of binding energy per nucleon (Eb/ A) versus the mass number (A) shows that nuclei with a small mass number have a small binding energy per nucleon, as the mass number increases the binding energy per nucleon increases, and the value for the binding energy per nucleon has a maximum value for nuclei with a mass number around 60. Verify that this is the case by determining the binding energy per nucleon for each of the following four nuclei. (Let the mass of a proton be 1.0078 u, the mass of a neutron be 1.0087 u, the mass of 2H be 2.0141 u, the mass of 7Li be 7.0160 u, the mass of 62Ni be 61.9283 u, and the mass of 110Cd be 109.9030 u.
a. 2H
b. 7Li
c. 62Ni
d. 110Cd
Answer:
a) 1.12 MeV / nucleon
b) 5.62 MeV / nucleon
c) 8.80 MeV / nucleon
d) 8.56 MeV / nucleon
we can conclude that the binding energy has a maximum value for nuclei with a mass around 60
Explanation:
Binding energy = ( Δm * 931.5 ) MeV
Binding energy per nucleon = Binding energy in / Number of nucleon
a) ²H = 1 neutron , 1 proton = 2 nucleons
Given that the theoretical mass = 2.0141 u
Actual mass = 1.0078 u + 1.0087 u = 2.0165 u
Δm = 2.0165 u - 2.0141 u = 2.4 * 10^-3 u
∴ Binding energy per nucleon = ( 2.4 * 10^-3 * 931.5 ) MeV / 2 nucleons
= 1.12 MeV / nucleon
b) ⁷Li = 3 protons , 4 neutrons = 7 nucleons
theoretical mass = 7.0160 u
Actual mass = ( 3 * 1.0078 ) + ( 4 * 1.0087 ) = 7.0582 u
Δm = ( 7.0582 u - 7.0160 u ) = 0.0422 u
∴ Binding energy per nucleon = ( 0.0422 * 931.5 ) / 7
= 5.62 MeV / nucleon
C) ⁶²Ni = 28 protons , 34 neutrons = 62 nucleons
Theoretical mass = 61.9283 u
Actual mass = ( 28 * 1.0078 ) u + ( 34 * 1.0087 ) u
= 62.5142 u
Δm = 0.5859 u
∴ Binding energy per nucleon = ( 0.5859 * 931.5 ) / 62
= 8.80 MeV / nucleon
D) ¹¹⁰Cd = 48 protons , 62 neutrons = 110 nucleons
Theoretical mass = 109.9030 u
Actual mass = ( 48 * 1.0078 ) + ( 62 * 1.0087 )
= 110.9138 u
Δm = ( 110.9138 - 109.9030 ) = 1.0108 u
∴ Binding energy per nucleon = ( 1.0108 * 931.5 ) / 110
= 8.56 MeV / nucleon
hence we can conclude that the binding energy has a maximum value for nuclei with a mass around 60
Given the following equation: 3C12 (g) + 8NH3 (g) → N2(g) +
ONH4Cl (S)
How many moles of NH3 are required to produce 12 moles of
NH4Cl?
Answer:
The balanced equation will be your greatest asset in Solving this.
The Balanced Equation is
3Cl2 + 8NH3---> N2 + 6NH4Cl
So
From this reaction...
3 moles of NH3 is required to produce 6 moles of NH4Cl
Now the question asked.... How Many Moles of NH3 will be needed to produce 12moles of NH4Cl?...
The answer is simply 6moles of NH3.
Why?
Since 3moles of NH3 produce 6 moles of NH4Cl
It makes sense that
6moles of NH3 will produce 12moles of NH4Cl.
Its a simple Ratio.
Hope this helps...
I'm Open to questions if you have any.
Have a great Day!
How many ML of 1.2 52 M KOH would be required to completely neutralize 9.55 ML of 0.114 HF
Answer:
0.871 mL
Explanation:
Step 1: Write the balanced neutralization reaction
KOH + HF ⇒ KF + H₂O
Step 2: Calculate the reacting moles of HF
9.55 mL of 0.114 M HF react.
9.55 × 10⁻³ L × 0.114 mol/L = 1.09 × 10⁻³ mol
Step 3: Calculate the moles of KOH needed to react with 1.09 × 10⁻³ moles of HF
The molar ratio of KOH to HF is 1:1. The moles of KOH needed are 1/1 × 1.09 × 10⁻³ mol = 1.09 × 10⁻³ mol.
Step 4: Calculate the volume of KOH solution that contains 1.09 × 10⁻³ moles of KOH
An unknown volume of 1.252 M KOH solution contains 1.09 × 10⁻³ moles of KOH.
1.09 × 10⁻³ mol × 1 L/1.252 mol = 8.71 × 10⁻⁴ L = 0.871 mL
1. Rearrange the letters to form a word.
1. OOTPSIL
2. BCDEROK
3. UHMSU
4. AOML
5. LCYA
science po ito
1- Topsoil
2- Bedrock
3- Humus
4- Loam
5- Acyl, Clay, or Lacy
Well that was fun :)
Answer:
Explanation:
1. TOPSOIL
2. BEDROCK
Water moves on, above or under the surface of the Earth true or false
above because its above
a buffer solution contain 0.1 mole per litres of acetic acid and 0.001 moles perlitre of sodium acetate.what will be its pH?(k=1.8×10-5)
Answer: The pH of the solution is 2.74.
Explanation:
To calculate the pH of the acidic buffer, the equation for Henderson-Hasselbalch is used:
[tex]pH=pK_a+\log (\frac{\text{[conjugate base]}}{\text{[acid]}})[/tex] .......(1)
The power of the acid dissociation constant is the negative logarithm of the acid dissociation constant. The equation for it is:
[tex]pK_a=-log K_a[/tex] ......(2)
The chemical equation for the reaction of acetic acid and NaOH follows:
[tex]CH_3COOH+NaOH\rightleftharpoons CH_3COONa+H-2O[/tex]
Given values:
[tex]K_a=1.8\times 10^{-5}[/tex]
Putting values in equation 2:
[tex]pK_a=-log (1.8\times 10^{-5})\\\\pK_a=4.74[/tex]
We are given:
[tex]CH_3COOH[/tex] = 0.1 M
[tex]CH_3COONa[/tex] = 0.001 M
Plugging values in equation 1:
[tex]pH=4.74+\log (\frac{0.001}{0.1})\\\\pH=4.74-2\\\\pH=2.74[/tex]
Hence, the pH of the solution is 2.74.
The shapes of the drops relate to the attractive forces between molecules in a compound. Based on their shapes, how does the attractive force between the water molecules compare with the attractive force between the oil molecules?
Answer:
Water molecule has hydrogen bonding and surface tension
Explanation:
Intermolecular behavior of water is different from that of the intermolecular force of oil because water molecule is polar in nature while oil molecule is non polar. Dur to polar nature, water molecule has high surface tension which keep its atoms intact. Also the water molecule being polar also exhibit hydrogen bonding between hydrogen (+ive) and oxygen atom (-ive)
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
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.
. Describe the movement of the Earth, The moon and the sun?
Answer:
Explanation:
It orbits
What type of decay changes the atomic number of the atom?
B. Translocation
C. Translation
D. Transuranium
A. Transmutation
Answer:
d
Explanation:did test
identify and name the functional
present in (i) C₂ H₂ (ii). CH₃ CH₂OH.
Answer:
I)Acetylene
II)2-Methyl-1-butanol
Explanation:
I)appears as a colorless gas with a faint garlic-like odor. Easily ignited and burns with a sooty flame. Gas is lighter than air.
HELP ME OMG
A sample of xenon gas collected at a pressure of 1.15 atm and a temperature of 279 K is found to
occupy a volume of 786 milliliters. How many moles of Xe gas are in the sample?
mol
n = 0.0395 mol Xe
Explanation:
Use the ideal gas law:
PV = nRT
n = PV/RT
= (1.15 atm)(0.786 L)/(0.08205 L-atm/mol-K)(279K)
= 0.0395 mol Xe
The solubility of an ionic compound can be expressed as the number of moles of the compound that will dissolve per liter of solution (molarity). The saturated solution has approximately____(a) sodium ions dissolved in it (give an estimate of the average value.) The solution (not the solid) contains approximately_____(b) moles of sodium ions.
Answer:
Number of moles of sodium dissolved = 6.0 *10^23
Explanation:
The image for the question is attached
Solution
a) Total 181 ions of Na are dissolved
b)
The number of moles of sodium dissolved = 181/6.023 *10^23
Number of moles of sodium dissolved = 5.987 * 10^23
Number of moles of sodium dissolved = 6.0 *10^23
Use the chart above to help you answer the following questions.
2Na + 2HCI →
2 NaCl
+ H
(s)
(aq)
(aq) 2(g)
? What are the reactants in the chemical reaction shown above?
Answer:
2Na and 2HCl
Explanation:
The equation for the above chemical reaction is as follows:
2Na + 2HCI → 2NaCl + H2
In a reaction, the reactants are said to be those that combine together to form products. In this case, sodium (Na) and hydrochloric acid (HCl) are the reactants of this reaction
are either positively charged or negatively charged species in which the number of protons and electrons are not equal. ____________ bonds are chemical bonds that results from the sharing of electrons. ____________ are positively charged ions with more ____________ than ____________ . ____________ ion is an example of a polyatomic anion. ____________ is the system of assigning an unambiguous name to a compound.
Answer:
1. Ions are either negatively or positively charged species in which the number of electrons and protons are not equal.
2. The chemical bond that arises due to the sharing of electrons is termed a covalent bond.
3. The positively charged ions are called cations, which comprise more protons than electrons.
4. An example of a polyatomic anion is the hydroxide anion.
5. The system of assigning an unambiguous name to a compound is called nomenclature.
How many hydrogen atoms are in 709 grams of water? Answer in units of atoms.
Answer:
26 Hydrogen atoms
Explanation:
H2O
Each hydrogen atom: 2+16 = 18g
Hence,
1 atom -> 18g
x atoms -> 709g
709/18 = 39 atoms
Therefore, 39 atoms give 709g
Hence, 26 Hydrogen atoms are used
Feel free to mark it as brainliest :D
Is this equation balanced or unbalanced?
C+02=CO2
1.State two uses of water at home.
2. State two uses of water in industries.
3. What is water conservation?
4. What are some methods of water conservation?
Helppppp!!!!!!
Answer:
1. Washing dishes and cooking
2. Water is used as a solvent in the manufacture of beverages and it is also largely used in agriculture.
3. Water conservation is the action of using water wisely and not wasting it.
4. i) Wash dishes in a tub of water instead of under a running tap.
ii) Use a pail of water to wash the car instead of spraying water from a hose.
iii) Make sure that there are no leaking or broken taps and pipes.
Answer:
Washing dishes and cooking
2. Water is used as a solvent in the manufacture of beverages and it is also largely used in agriculture.
3. Water conservation is the action of using water wisely and not wasting it.
4. i) Wash dishes in a tub of water instead of under a running tap.
ii) Use a pail of water to wash the car instead of spraying water from a hose.
iii) Make sure that there are no leaking or broken taps and pipes.
Explanation:
Calculate the pH when (a) 24.9 mL and (b) 25.1 mL of 0.100 M HNO3 have been added to 25.0 mL of 0.100 M KOH solution.
Answer:
Suppose you added some solid NaCl to a saturated solution of NaCl at 20℃ and warmed the mixture to 40℃. What would happen to the added NaCl?
Explanation:
can you help with this one
Predict the effect of an eightfold pressUre increase on the equillbrium composition of the reaction 3 Nalg) + H2lg) 2 NaHlg)
Answer:
See explanation
Explanation:
Given the reaction;
3N2(g) + H2(g) = 2N3H(g).
We know that when a constraint is imposed on a reaction system in equilibrium, the equilibrium position will shift in such a way as to annul the constraint.
In this case, when the pressure is increased eightfold, the equilibrium position will shift towards the direction where there is the least total volumes.
In this particular reaction, the forward reaction has the least total volumes and is favoured by an eightfold increase in pressure.
Hence, when the pressure is increased eightfold, more N3H(g) is obtained.
write the manufacturing process of oxygen gas from liquid air
Answer:
Production of liquid oxygen from air Oxygen is generated by liquefaction of atmospheric air in the air separation unit (ASU). Cryogenic technique is the most commonly used for producing liquid oxygen for industrial and medical applications .
Explanation:
An air separation unit (ASU) uses continuous cryogenic distillation to continuously liquefy ambient air and separate the oxygen gas.
What is oxygen?Oxygen is the second largest abundant element in the atmosphere comprising 20.8% by volume. Despite being mostly used as a gas, oxygen is frequently stored as a liquid. Compared to high-pressure gaseous storage with a similar capacity, liquid storage is less expensive and bulkier.
A cryogenic storage tank, one or more vaporizers, and a pressure control system make up a typical storage system. The cryogenic tank is built similarly to a vacuum bottle.
The primary air compressor is where the ASU manufacturing process starts, and the product storage tanks' output is where it concludes. Moisture, carbon dioxide, and hydrocarbons are taken out of the air after it has been compressed and put through a purification system.
To find more on oxygen manufacturing, refer here:
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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
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
Balance the following equation by LCM method.Mg + H2O = Mg(OH)2 + H2
Answer:
Mg + 2H₂O —> Mg(OH)₂ + H₂
Explanation:
Mg + H₂O —> Mg(OH)₂ + H₂
The above equation can be balance as illustrated below:
Mg + H₂O —> Mg(OH)₂ + H₂
There are 2 atoms of H on the left side and a total of 4 atoms on the right side. It can be balance by writing 2 before H₂O as shown below:
Mg + 2H₂O —> Mg(OH)₂ + H₂
Now, the equation is balanced
****Check***
Element >>>>> Reactant >>>> Product
Mg >>>>>>>>>> 1 >>>>>>>>>>> 1
H >>>>>>>>>>> 4 >>>>>>>>>>> 4
O >>>>>>>>>>> 2 >>>>>>>>>>> 2
The balanced equation of Mg + H2O = Mg(OH)2 + H2 is given as
Mg + 2H₂O —> Mg(OH)₂ + H₂
What is the balance equation?Generally, the equation for the Chemical equation is mathematically given as
Mg + H₂O —> Mg(OH)₂ + H₂
Therefore, We se that we have on the LHS
Mg=1
H=2
O=1
and on The RHS
Mg=1
H=4
O=2
Therefore to balance, we add 2 to H and 1 to O giving
Mg + 2H₂O —> Mg(OH)₂ + H₂
Read more on Chemical equation
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Calculate the density of a solid substance if a cube measuring 2.54 cm on one side has a mass of 108 g/cm3
Answer:
6.59 g/cm³
Explanation:
Step 1: Given data
Side of the cube (s): 2.54 cmMass of the cube (m): 108 gStep 2: Calculate the volume of the cube
We will use the following expression.
V = s³ = (2.54 cm)³ = 16.4 cm³
Step 3: Calculate the density of the solid
Density is an intrinsic property, equal to the quotient between the mass and the volume.
ρ = m/V
ρ = 108 g / 16.4 cm³ = 6.59 g/cm³
When an acid reacts with a strong base which product always forms
Answer:طيزي
Explanation:
Many ski resorts and mountain cities can be reached directly by planes which deposit travelers a mile or more above sea level. This can result in altitude sickness due to hypoxemia, or reduced oxygen in the blood, caused by the unaccustomed exposure to the lower atmospheric pressure at high elevations. On a given day, the prevailing atmospheric pressure in Yellowstone, MT (elevation 2031 meters) might be 0.775 atm. Calculate this pressure expressed in mmHg and in torr.
Answer:
589 torr or mmHg.
Explanation:
We know that 1 atmospheric pressure is equal to 760 torr or 760 mmHg so calculate 0.775 atm pressure in term of mmHg and torr. We perform the following steps which is
1 atm -------- 760 torr or mmHg
0.775 atm ------- X
By cross multiplication we get
X = 760 x 0.775
X = 589 torr or mmHg
So we can conclude that if 0.775 atm is equals to 589 torr.