Answer:
Hydrogen and fuel cell technologies power cars, buildings and more. But how ... Test your knowledge with this quiz! ... How do fuel cells generate electricity
Answer:
A
Explanation:
fuel cell is a device that converts the chemical energy from fuel into electricity via a chemical reaction with oxygen or another oxidizing agent. Batteries work in a closed system, while fuel cells require their reactants to be replenished.
A weak acid is titrated with 0.1236 M NaOH. From the titration curve you determine that the equivalence point occurs after exactly 12.42 mL of NaOH have been added. What is the volume of NaOH at the half-equivalence point (a.k.a. the midpoint)
Answer: The volume of NaOH required at the half-equivalence point is 6.21 mL
Explanation:
The chemical equation for the reaction of a weak acid with NaOH follows:
[tex]HA+ NaOH\rightarrow NaA+H_2O[/tex]
From the equation, we can say that NaOH and weak acid is present in a 1 : 1 ratio.
We are given:
Volume of NaOH required at equivalence point = 12.42 mL
The volume of NaOH required at half-equivalence point will be = [tex]\frac{12.42mL}{2}=6.21mL[/tex]
Hence, the volume of NaOH required at the half-equivalence point is 6.21 mL
The volume of NaOH at the half-equivalence point is 6.21 mL
What is equivalence point?The equivalence point is the point at which equal amount of the acid and base have reacted.
How to determine the half-equivalence pointVolume at equivalence point = 12.42 mLVolume at half-equivalence point =?Half equivalence point = Equivalence point / 2
Half equivalence point = 12.42 / 2
Half equivalence point = 6.21 mL
Therefore, we can conclude that the volume of NaOH at the half-equivalence point is 6.21 mL.
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Calculate the energy in kj/mol of photon in red light of wavelength 656nm
Answer:
you don't know the answer?ha me too
Chemistry Grade 11: Hi, I don't know what this is, please help?
CALCULATING % YIELD STEPS:
1.
2.
3.
4.
Answer:
1. Write the balanced chemical equation for the reaction
2. Identify all important information provided in the word problems or data table.
3. Solve for the theoretical yield of the reaction, following all the steps of a stoichiometry calculation organizer. Use two calculations if both reactants are provided.
4. Use the percent yield equation to calculate the percent yield of the reaction.
Explanation:
its comes right from the 5.06 lesson
Based on your knowledge of factors affecting the rate of reaction, why is there a danger of explosions in places such as flour mills and coal mines where there are large quantities of powdered, combustible materials?
Answer:
See Explanation
Explanation:
Rate of reaction refers to how quickly or slowly a reaction proceeds. The rate of reaction depends on certain factors.
Two among the factors that affect the rate of reaction are the concentration of reactants and the surface area of reactants.
The more the concentration of reactants, the faster the rate of reactants because there is a high possibility of collision between reactants. Also, the higher the surface area of reactants, the greater the rate of reaction.
In flour mills and coal mines where there is a large amount (concentration) of combustible materials and the particles are powdered (high surface area), there is a greater risk of explosion due to a high rate of reaction owing to a combination of the two factors discussed above.
How is the atomic mass unit found
Answer:
yo its jess bregoli
your answer is given below
(◠‿◕)
An atomic mass unit is defined as a mass equal to one twelfth the mass of an atom of carbon-12. The mass of any isotope of any element is expressed in relation to the carbon-12 standard. For example, one atom of helium-4 has a mass of 4.0026 amu. An atom of sulfur-32 has a mass of 31.972 amu.
When metal X is treated with sodium hydroxide, a white precipitate A is obtained which is soluble in excess NaOH to give a soluble complex B. Compound A is soluble in dilute HCl to form compound C. When the compound A is heated strongly it gives compound D which is used to extract metal. a) Identify X, A, B, C, D supporting your answer(s) with appropriate chemical reactions. b) At which group and period does X fall?
Answer:
See explanation
Explanation:
If we look at the question closely, we will notice that the metal in question must be aluminum.
When aluminum is treated with sodium hydroxide, a precipitate, aluminium hydroxide is formed as follows;
Al(s) + 3NaOH(aq) ---> Al(OH)3(s) + 3Na(s)
In excess sodium hydroxide, the precipitate dissolves as follows;
Al(OH)3(s) + NaOH(aq) ----> [NaAlOH4]^-(aq)
The complex formed is sodium aluminum tetrahydroxo aluminate III.
The reaction of aluminum faith dilute hydrochloric acid occurs as follows to yield aluminum chloride;
2Al(s) + 6HCl(aq) ----> 2AlCl3(aq) + 3H2(g)
When aluminum metal is heated strongly, it yields aluminum oxide;
2Al(s) + 3O2(g) ---> Al2O3(s)
Which of the following is a protein source of plant origin
Answer:
soy....plant protein also is found in vegtables and grain products.
The protein that is derived from the plant is soyabean. Protein-rich foods have a rich source of amino acids. Amino acids are required by the body for different cellular activities.
What are proteins?
Proteins are present in plant-based foods and animal-based foods. In nature, the plant-based foods that are rich in proteins are soybeans, beans etc. Animal products such as dairy products, milk, and cheese are rich sources of proteins.
Animal-based foods such as eggs, meat, and fish have a good amount of protein. The proteins are made up of amino acids. Peptide bonds connect each amino acid to the next.
Proteins are necessary for the body, as cells need amino acids for both structural and functional support. Not all cells of the body synthesise all amino acids. Some essential amino acids are required by the body and can be taken from external sources such as plants.
Hence, the plant-based protein is soyabean.
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The question is incomplete; the complete question may be the following:
1) Which of the following is a protein source of plant origin?
A)egg
B) Soyabean
C)cheese
D)Milk
2) If the density of chloroform is 1.48 g/mL, what is the volume of 541 g of chloroform?
Answer:
V = 365.54 mL
Explanation:
Given that,
The density of chloroform, d = 1.48 g/mL
The mass of chloroform, m = 541 g
We need to find the volume of chloroform.
We know that,
Density = mass/volume
So,
[tex]V=\dfrac{m}{d}\\\\V=\dfrac{541\ g}{1.48\ g/mL}\\\\=365.54\ mL[/tex]
So, the volume of chloroform is 365.54 mL.
Compare the solubility of silver chloride in each of the following aqueous solutions:
a. 0.10 M AgNO3 More soluble than in pure water.
b. 0.10 M NaCI Similar solubility as in pure water
c. 0.10 M KNO3 Less soluble than in pure water.
d. 0.10 M NH4CH3COO
Answer:
Compare the solubility of silver chloride in each of the following aqueous solutions:
a. 0.10 M AgNO3 More soluble than in pure water.
b. 0.10 M NaCI Similar solubility as in pure water
c. 0.10 M KNO3 Less soluble than in pure water.
d. 0.10 M NH4CH3COO
Explanation:
This is based on common ion effect.
According to common ion effect, the solubility of a sparingly soluble salt decreases in a solution containing common ion to it.
The solubility of AgCl(s) is shown below:
[tex]AgCl(s) <=> Ag^{+}(aq)+Cl^-(aq)[/tex]
So, when it is placed in:
a. 0.10 M AgNO3
Due to common ion effect Ag+, its solubility is less in this solution than in pure water.
b. 0.10 M NaCI :
Due to common ion effect Cl-, its solubility is less in this solution than in pure water.
c. 0.10 M KNO3 :
In this solution there is no presence of common ion.
So, the solubility of AgCl in this solution is similar to that of pure water.
d. 0.10 M NH4CH3COO:
In this solution, AgCl forms a precipitate.
So, the solubility of AgCl is more in this solution compared to pure water.
Compound A and compound B are constitutional isomers with molecular formula C3H7Cl. When compound A is treated with sodium methoxide, a substitution reaction predominates. When compound B is treated with sodium methoxide, an elimination reaction predominates.
Required:
Propose structures A and B.
Answer:
Compound A and compound B are constitutional isomers with molecular formula C3H7Cl.
When compound A is treated with sodium methoxide, a substitution reaction predominates. When compound B is treated with sodium methoxide, an elimination reaction predominates.
Explanation:
Constitutional isomers are the one which differs in the structural formula.
When compound A is treated with sodium methoxide, a substitution reaction predominates.
That means sodium methoxide is a strong base and a strong nucleophile.
But when it reacts with primary alkyl halides it forms a substitution product and when it reacts with secondary alkyl halide it forms mostly elimination product.
The reaction and the structures of A and B are shown below:
Question 11
1 pts
A solution is formed by dissolving 45 grams of NH4Cl in
100 grams of H20 at 70°C. Which statement correctly
describes this solution?
O NH4Cl is the solute, and the solution is saturated.
O NH4Cl is the solute, and the solution is unsaturated.
o NH4Cl is the solvent, and the solution is unsaturated.
O NH4Cl is the solvent, and the solution is saturated.
< Previous
Answer:
NH4Cl is the solute, and the solution is unsaturated.
Explanation:
To create a saturated solution of ammonium chloride at 70°C, we need to dissolve 62 g of ammonium chloride in 100 g of water.
The question tells us that 45 grams of NH4Cl was dissolved in 100 grams of H20 at 70°C. This creates an unsaturated solution since the amount of solute present is less than the amount of solute that the NH4Cl solution can normally hold at 70°C.
Hence, NH4Cl is the solute, and the solution is unsaturated.
what is a property of every mixture
Explanation:
can u post a picture of the question ?
An organelle that is not found in this illustration of a cell would be
A. the cell wall
B. chromosome
C. mitochondria
D. the cell membrane
Answer:
The answer is cell wall
Explanation:
Because it is
Define solubility. a solid that does not dissolve in a gas the amount of a substance that will dissolve in a given amount of solvent the amount of a substance that will dissolve in a given amount of solute a liquid that does not dissolve in another liquid a solid mixed with another solid
Answer:
the amount of a substance that will dissolve in a given amount of solvent.
Explanation:
Solubility is a term used to describe how readily a substance can be dissolved in a solvent to form a solution. Thus, a substance is said to be soluble if it dissolves completely in a solvent and insoluble if it doesn't dissolve or only dissolves partially.
For example, sodium chloride (NaCl) when mixed with water dissociates into sodium and chloride ions. Thus, salt (sodium chloride) is said to be soluble because it dissolves completely in water.
Furthermore, a compound that dissolves completely in water to produce an aqueous solution is said to be soluble in water.
In conclusion, solubility is simply the amount of a substance such as salt, that will dissolve in a given amount of solvent. A solvent is any liquid such as water, coffee, tea, etc., that dissolves a liquid, gaseous, or solid solute to produce a solution.
An experiment was performed under identical conditions as yours. The absorbance of the penny solution was recorded as 0.219 absorbance units. A calibration plot of absorbance vs. concentration of Cu(II) (M) yielded the following trendline equation:
y= 11.589x - 0.0002
Required:
What is the concentration (mol/L) of the penny solution?
Answer:
Concentration C = 0.0189 mol/L
Explanation:
From the given information:
Let consider the formula used in calculating the concentration according to Beer's law:
[tex]\mathtt{A =\varepsilon \times L \times C}[/tex] --- (1)
here;
A = absorbance
ε = coefficient of molar absorptivity
L = path length
C = concentration (mol/L)
Also, from Beer law plot:
y = mx+b
where,
y represent absorbance A
b represents intercept
m represents the coefficient of molar absorptivity ε
and x represents the concentration(C).
replacing the substituted entities
A = ε × C + b ---- (2)
Making the concentration the subject of the above formula:
[tex]C = \dfrac{A-b}{\varepsilon}[/tex]----(3)
From y = 11.589x - 0.0002
A = 11.589 *C - 0.0002
Given that:
A = 0.219
∴
0.219 = 11.589 *C - 0.0002
0.219 + 0.0002 = 11.589 *C
C = 0.2192/11.589
C = 0.0189 mol/L
What are the main modifications of John Dalton's atomic theory
Match each term to the best description.
a. Blue-gray color
b. Chelating agent
c. EBT
d. EDTA
e. Pale purple-pink color
1. Eriochrome Black T
2. Starting color, before titration
3. Molecule that has a high affinity for ions
4. Ethylenediaminetetracetlc acid
5. Color at the completion of titration
Solution :
Term Best description
Eriochrome Black T EBT
Starting color, before titration Pale purple-pink color
Molecule that has a high affinity for metal ions Chelating agent
Ethylenediaminetetracetic acid EDTA
Color at the completion of titration Blue-gray color
which is the correct orbital diagram for carbon
Answer:
Below
Explanation:
Got it right
Check the periodic table, then click electrons
PLZZZ HELPPPPPPPPPPPPPPPP
Calcular el pH de una disolución cuando 10 g de NaOH se diluyen con agua hasta un volumen final de 250 ml
Answer:
My nettttttworkkkk is slowww
Phosphorus pentachloride, PCl5, a white solid that has a pungent, unpleasant odor, is used as a catalyst for certain organic reactions. Calculate the number of moles in 38.7 g of PCl5.
Answer:
0.186 moles
Explanation:
In order to convert grams of PCl₅ into moles, we need to use its molar mass:
Molar Mass of PCl₅ = Molar mass of P + (Molar mass of Cl)*5Molar Mass of PCl₅ = 208.24 g/molThen we proceed to calculate the number of moles:
38.7 g ÷ 208.24 g/mol = 0.186 molThere are 0.186 moles of PCl₅ in 38.7 g of PCl₅.In the given question Phosphorus pentachloride is used as a catalyst for certain chemical reaction. 38.7 g of [tex]\rm PCl_5[/tex], there are 0.186 moles of [tex]\rm PCl_5[/tex].
A catalyst is a substance that increases the rate of a chemical reaction by lowering the activation energy required for the reaction to occur.
To calculate the number of moles in 38.7 g of [tex]\rm PCl_5[/tex], we need to divide the given mass of [tex]\rm PCl_5[/tex] by its molar mass.
The molar mass of [tex]\rm PCl_5[/tex] can be calculated by adding the atomic masses of one phosphorus atom and five chlorine atoms:
Molar mass of [tex]\rm PCl_5[/tex] = (1 x atomic mass of P) + (5 x atomic mass of Cl)
= (1 x 30.97 g/mol) + (5 x 35.45 g/mol)
= 208.22 g/mol
Now, we can calculate the number of moles of [tex]\rm PCl_5[/tex]:
Number of moles = mass / molar mass
= 38.7 g / 208.22 g/mol
= 0.186 moles
Therefore, there are 0.186 moles of [tex]\rm PCl_5[/tex] in 38.7 g of [tex]\rm PCl_5[/tex].
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Boiling point-methanol (65.0) 66.8c.Boiling point-unknown (record from video)——-c
Identify of unknown:
Possibilities are:Mathanol65.0c;Ethanol 78.5c; Acetone 56.0C
Calculate the pressure exerted by 40 g of oxygen enclosed in a 1litre flask at 25°C. (0=16) (3 Marks)
Answer:
I don't know sorry siso
Explanation:
I don't know
Which of the following is NOT true about soil? *
Match each term with the best description.
a. The electrode where oxidation occurs
b. A device that produces electricity
c. The connection between two half-cells
d. The electrode where reduction occurs
e. A device that consumes electricity
f. A device that utilizes redox reactions to either consume or produce electricity
1. Anode
2. Cathode
3. Electrolytic cell
4. Electrochemical
5. Galvanic cell
6. Salt bridge
Answer:
Match each term with the best description.
a. The electrode where oxidation occurs: Anode
b. A device that produces electricity: Galvanic cell
c. The connection between two half-cells: salt bridge
d. The electrode where reduction occurs: Cathode
e. A device that consumes electricity: Electrolytic cell
f. A device that utilizes redox reactions to either consume or produce electricity: Electrochemical cell.
Explanation:
a.The electrode where oxidation occurs is called the anode.
Oxidation is losing of electrons.
b. Galvanic cell produces electricity by using redox chemical reaction.
It is also called a voltaic cell or electrochemical cell.
c. The connection between two cells is called a salt bridge.
It will not allow the solutions to diffuse with each other.
It maintains electrical neutrality.
d. The electrode where reduction occurs: Cathode
Reduction means the gaining of electrons.
e. Electrolytic cell is the one that consumes electricity and then produces a chemical change.
f. A device that utilizes redox reactions to either consume or produce electricity: Electrochemical cell.
n a combination redox reaction, two or more ____________ , at least one of which is a(n) ____________ , form a(n) ____________ . General Reaction: ____________ In a decomposition redox reaction, a(n) ____________ forms two or more ____________ , at least one of which is a(n) ____________ . General Reaction: ____________ In double-displacement (metathesis) reactions, such as precipitation and acid-base reactions, ____________ of two ____________ exchange places; these reactions ____________ redox processes.General Reaction: ____________ In solution, single-displacement reactions occur when a(n) ____________ of one ____________ displaces the ____________ of another. Since one of the ____________ is a(n) ____________ , a
Answer:
In a combination redox reaction, two or more reactants, at least one of which is a(n) element, form a(n) compound. General Reaction: X + Y > Z
In a decomposition redox reaction, a(n) compound forms two or more products, at least one of which is a(n) element. General Reaction: Z>X+Y
In double-displacement (metathesis) reactions, such as precipitation and acid-base reactions, atoms (or ions) of two compounds exchange places; these reactions are not redox processes. General Reaction: AB+CD>AD+CB
In solution, single-displacement reactions occur when a(n) atom of one element displaces the atom of another. Since one of the reactants is a(n) element, all single-displacement reactions are redox processes. General Reaction: X+YZ>XY+Z
Explanation:
In a combination redox reaction, two or more reactants, at least one of which is a(n) element, form a(n) compound.
General Reaction: X + Y > Z
In the reaction scheme above, X combines with Y to give Z as a product.
In a decomposition redox reaction, a(n) compound forms two or more products, at least one of which is a(n) element.
General Reaction: Z>X+Y
In the reaction scheme above, Z decomposes to X and Y
In double-displacement (metathesis) reactions, such as precipitation and acid-base reactions, atoms (or ions) of two compounds exchange places; these reactions are not redox processes since there are no changes occurring in the oxidation number of the atoms (or ions) involved.
General Reaction: AB+CD>AD+CB
In the reaction scheme above, B and D exchange places in their respective compounds
In solution, single-displacement reactions occur when a(n) atom of one element displaces the atom of another. This type of reaction is due to the difference in the reactivities of the elements. The more reactive atom of one element displaces the least reactive atom of another element from its solution.
Since one of the reactants is a(n) element, all single-displacement reactions are redox processes.
General Reaction: X+YZ>XY+Z
In the reaction scheme above, X displaces Z from the compound YZ.
In Denver, Colorado the elevation is about 5,280 feet above sea level. Explain what potential effects this may have on the solubility of a gaseous solute in a liquid solution.
Answer:
The solubility of the gaseous solute decreases
Explanation:
As we know, pressure decreases with altitude. This means that, at higher altitudes, the pressure is much lower than it is at sea level.
The solubility of a gas increases with increase in pressure and decreases with decrease in pressure.
Hence, in Denver, Colorado where the elevation is about 5,280 feet above sea level, a gaseous solute is less soluble than it is at sea level due to the lower pressure at such high altitude.
A 0.15 M solution of BaCl2 contains: Group of answer choices 0.30 M Ba2 ions and 0.30 M Cl- ions. 0.15 M Ba2 ions and 0.15 M Cl- ions. 0.30 M Ba2 ions and 0.15 M Cl- ions. 0.15 M Ba2 ions and 0.30 M Cl- ions. none of the above
Answer:
0.15 M Ba⁺² ions and 0.30 M Cl⁻ ions
Explanation:
The dissociaton of barium chloride is as follows:
BaCl₂ → Ba²⁺ + 2Cl⁻
By observing the stoichiometric coefficients, we can tell that the number of moles of Ba²⁺ is the same as the number of moles of BaCl₂, while the number of moles of Cl⁻ is the double of that.
Spell out the full name of the compound.
Submit
Help plz
Explanation:
A=Butan-2-one
B=Pentan-3-one
A 420 mL sample of a 0.100 M formate buffer, pH 3.75, is treated with 7 mL of 1.00 M KOH. What is the pH following this addition? (pKa for formic acid is 3.75)
Answer: The pH of the resulting solution will be 3.60
Explanation:
Molarity is calculated by using the equation:
[tex]\text{Molarity}=\frac{\text{Moles}}{\text{Volume}}[/tex] ......(1)
We are given:
Molarity of formic acid = 0.100 M
Molarity of potassium formate = 0.100 M
Volume of solution = 420 mL = 0.420 L (Conversion factor: 1 L = 1000 mL)
Putting values in equation 1, we get:
[tex]\text{Moles of formic acid}=(0.100mol/L\times 0.420L)=0.0420mol[/tex]
[tex]\text{Moles of potassium formate}=(0.100mol/L\times 0.420L)=0.042mol[/tex]
Molarity of KOH = 1.00 M
Volume of solution = 7 mL = 0.007 L
Putting values in equation 1, we get:
[tex]\text{Moles of KOH}=(1mol/L\times 0.007L)=0.007mol[/tex]
The chemical equation for the reaction of formic acid and KOH follows:
[tex]HCOOH+KOH\rightleftharpoons HCOOK+H_2O[/tex]
I: 0.042 0.007 0.042
C: -0.007 -0.007 +0.007
E: 0.035 - 0.049
Volume of solution = [420 + 7] = 427 mL = 0.427 L
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] .......(2)
Given values:
[tex][HCOOK]=\frac{0.049}{0.427}[/tex]
[tex][HCOOH]=\frac{0.035}{0.427}[/tex]
[tex]pK_a=3.75[/tex]
Putting values in equation 2, we get:
[tex]pH=3.75-\log \frac{(0.049/0.427)}{(0.035/0.427)}\\\\pH=3.75-0.146\\\\pH=3.60[/tex]
Hence, the pH of the resulting solution will be 3.60
