Answer:
1.207 ××10⁻¹⁷ J
Explanation:
Step 1: Given and data
Frequency of the photon (ν): 1.821 × 10¹⁶ s⁻¹Planck's constant (h): 6.626 × 10⁻³⁴ J.sStep 2: Calculate the energy (E) of the photon
We will use the Planck-Einstein's relation.
E = h × ν
E = (6.626 × 10⁻³⁴ J.s) × ( 1.821 × 10¹⁶ s⁻¹) = 1.207 ××10⁻¹⁷ J
what is the characteristics of tropical air mass
Answer:
Explanation:
Continental tropical air masses are extremely hot and dry. Arctic, Antarctic, and polar air masses are cold. The qualities of arctic air are developed over ice and snow-covered ground. Arctic air is deeply cold, colder than polar air masses.
A barium hydroxide solution is prepared by dissolving 2.29 g of Ba(OH)2 in water to make 46.6 mL of solution. What is the concentration of the solution in units of molarity?
Concentration: 0.287 M
The barium hydroxide solution is used to titrate a perchloric acid solution of unknown concentration. Write a balanced chemical equation to represent the reaction between barium hydroxide and perchloric acid.
Chemical Equation:
If 25.5 mL of the barium hydroxide solution was needed to neutralize a 8.99 mL aliquot of the perchloric acid solution, what is the concentration of the acid?
Concentration:
Answer:
0.287 M
Ba(OH)₂ + 2 HClO₄ ⇒ Ba(ClO₄)₂ + 2 H₂O
1.62 M
Explanation:
Step 1: Calculate the concentration of Ba(OH)₂
We will use the following expression.
[Ba(OH)₂] = mass Ba(OH)₂/ molar mass Ba(OH)₂ × liters of solution
[Ba(OH)₂] = 2.29 g/ 171.34 g/mol × 0.0466 L = 0.287 M
Step 2: Write the balanced neutralization equation
Ba(OH)₂ + 2 HClO₄ ⇒ Ba(ClO₄)₂ + 2 H₂O
Step 3: Calculate the reacting moles of Ba(OH)₂
25.5 mL of 0.287 M Ba(OH)₂ react.
0.0255 L × 0.287 mol/L = 7.32 × 10⁻³ mol
Step 4: Calculate the reacting moles of HClO₄
7.32 × 10⁻³ mol Ba(OH)₂ 2 mol HClO₄/1 mol Ba(OH)₂ = 0.0146 mol HClO₄
Step 5: Calculate the concentration of HClO₄
0.0146 moles of HClO₄ are in 8.99 mL of solution.
[HClO₄] = 0.0146 mol/0.00899 L = 1.62 M
At 50.0 oC, a reinforced tank contains 675.5 grams of gaseous argon and 465.0 g of gaseous molecular chlorine with a total pressure of 4.00 atm. Calculate the following:
a. How many moles of Ar are in the tank?
b. How many moles of Cl, are in the tank?
c. Total moles of gas in the tank.
d. The mole fraction of Ar.
e. The mole fraction of Cl2.
f. The Partial Pressure of Ar.
g. The Partial Pressure of Cl2.
Answer:
For (a): The moles of Ar is 16.94 moles
For (b): The moles of [tex]Cl_2[/tex] is 16.94 moles
For (c): The total number of moles in a tank is 23.47 moles
For (d): The mole fraction of Ar is 0.722
For (e): The mole fraction of [tex]Cl_2[/tex] is 0.278
For (f): The partial pressure of Ar is 2.888 atm
For (g): The partial pressure of [tex]Cl_2[/tex] is 1.112 atm
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
For (a):Given mass of Ar = 675.5 g
Molar mass of Ar = 39.95 g/mol
Plugging values in equation 1:
[tex]\text{Moles of Ar}=\frac{675.5g}{39.95g/mol}=16.91 mol[/tex]
For (b):Given mass of [tex]Cl_2[/tex] = 465.0 g
Molar mass of [tex]Cl_2[/tex] = 70.9 g/mol
Plugging values in equation 1:
[tex]\text{Moles of }Cl_2=\frac{465.0g}{70.9g/mol}=6.56 mol[/tex]
For (c):Total moles of gas in the tank = [16.91 + 6.56] mol = 23.47 mol
Mole fraction is defined as the moles of a component present in the total moles of a solution. It is given by the equation:
[tex]\chi_A=\frac{n_A}{n_A+n_B}[/tex] .....(2)
where n is the number of moles
For (d):Moles of Ar = 16.94 moles
Total moles of gas in the tank = 23.47 mol
Putting values in equation 2, we get:
[tex]\chi_{Ar}=\frac{16.94}{23.47}\\\\\chi_{Ar}=0.722[/tex]
For (e):Total mole fraction of the system is always 1
Mole fraction of [tex]Cl_2[/tex] = [1 - 0.722] = 0.278
Raoult's law is the law used to calculate the partial pressure of the individual gases present in the mixture.
The equation for Raoult's law follows:
[tex]p_A=\chi_A\times p_T[/tex] .....(3)
where [tex]p_A[/tex] is the partial pressure of component A in the mixture and [tex]p_T[/tex] is the total partial pressure of the mixture
For (f):We are given:
[tex]\chi_{Ar}=0.722\\p_T=4.00atm[/tex]
Putting values in equation 3, we get:
[tex]p_{Ar}=0.722\times 4.00atm\\\\p_{Ar}=2.888atm[/tex]
For (g):We are given:
[tex]\chi_{Cl_2}=0.278\\p_T=4.00atm[/tex]
Putting values in equation 3, we get:
[tex]p_{Cl_2}=0.278\times 4.00atm\\\\p_{Cl_2}=1.112atm[/tex]
how many atoms of one formula unit in Fe2O3
Answer:
5 atoms form one formula unit of Fe2O3
Explanation:
2 atoms of Fe (Iron)
and 3 atoms of O ( Oxygen)
so total = 3 + 2
= 5
Answer:
fe203 the right answer is thus
When H2S(g) reacts with O2(g) to form H2O(g) and SO2(g), 124 kcal of energy are evolved for each mole of H2S(g) that reacts. Write a balanced equation for the reaction with an energy term in kcal as part of the equation.
Answer:
2H2S(g) + 3O2(g) → 2H2O(g) + 2SO2(g) + 248kcal
Explanation:
The reaction of the problem occurs as follows:
H2S(g) + O2(g) → H2O(g) + SO2(g)
To balance the reaction we must balance oxygens:
H2S(g) + 3O2(g) → 2H2O(g) + 2SO2(g)
To balance the complete reaction:
2H2S(g) + 3O2(g) → 2H2O(g) + 2SO2(g)
As the energy is evolved, 124kcal are as product in the reactio per mole of H2S. As the balanced reaction contains 2 moles of H2S, the heat evolved is:
124kcal*2 = 248kcal:
2H2S(g) + 3O2(g) → 2H2O(g) + 2SO2(g) + 248kcal
And this is the balanced equation
A chemist requires a large amount of 1-bromo-4-phenyl-2-butene as starting material for a synthesis and decides to carry out the following NBS allylic bromination reaction in the presence of UV light. Draw the structures of all of the observed products.
NBS
(C6H5)CH2CH = CHCH3 → ?
CCI4
Draw one additional resonance structure for the species below:
CH3CH=CHCH=CHCH=CHCH2
Answer:
CH 2 CH 3 CHCH = C6H5 + 5 Hydrogen Atoms
I hope I helped you.
Deepest apologies if I was wrong!
Bye!
~ Myaka O.
the empirical formula of a compound is CH2 N2 and its molecular mass is 126.0. what is the molecular formula of the compound
Step 1: Represent a molecular formula.
[tex]\text{molecular formula} = (\text{CH}_{2}\text{N}_{2})_{n}[/tex]
Step 2: Calculate the empirical mass.
empirical mass = (12.0 g/mol × 1) + (1.0 g/mol × 2) + (14.0 g/mol × 2)
empirical mass = 42.0 g/mol
Step 3: Divide the molecular mass by the empirical mass.
[tex]n = \frac{\text{molecular mass}}{\text{empirical mass}}[/tex]
[tex]n = \frac{\text{126.0}}{\text{42.0}}[/tex]
[tex]n = 3[/tex]
Step 4: Multiply the subscripts by the value of n to obtain the molecular formula.
[tex]\text{molecular formula} = (\text{CH}_{2}\text{N}_{2})_{3}[/tex]
[tex]\boxed{\text{molecular formula} = \text{C}_{3}\text{H}_{6}\text{N}_{6}}[/tex]
[tex]\\[/tex]
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hợp chất nào có khả năng là hợp chất ion cao nhất ?
A Al2O3
B ScCl3
C NO2
D CCl4
Answer:
B
Explanation:
hợp chất nào có khả năng là hợp chất ion cao nhất ?
A Al2O3?
B
A chemist adds 370.0mL of a 1.41/molL potassium iodide KI solution to a reaction flask. Calculate the millimoles of potassium iodide the chemist has added to the flask. Be sure your answer has the correct number of significant digits.
Answer: The millimoles of potassium iodide the chemist has added to the flask is 522 millimoles.
Explanation:
Given: Volume of KI = 370.0 mL (1 mL = 0.001 L) = 0.37 L
Molarity of KI solution = 1.41 mol/L
Now, moles of KI (potassium iodide) is calculated as follows.
[tex]Moles = Volume \times Molarity \\= 0.37 L \times 1.41 M\\= 0.5217 mol[/tex]
Convert moles into millimoles as follows.
1 mol = 1000 millimoles
0.5217 mol = [tex]0.5217 mol \times \frac{1000 millimoles}{1 mol} = 521.7 millimoles[/tex]
This can be rounded off to the value 522 millimoles.
Thus, we can conclude that the millimoles of potassium iodide the chemist has added to the flask is 522 millimoles.
Draw the structures and provide the names of all the isomeric alcohols that have the molecular formula C4H10O Draw the structures of (a) 6-methyl-3-heptanol and (b) trans-2-methylcyclohexanol
Answer:
Draw the structures and provide the names of all the isomeric alcohols that have the molecular formula C4H10O.
Draw the structures of (a) 6-methyl-3-heptanol and (b) trans-2-methylcyclohexanol
Explanation:
Isomers are compounds with the same molecular formula but different structural arrangements of atoms.
The given molecule is:
C4H10O.
The possible isomeric alcohols structures are shown below:
Structure of (a) 6-methyl-3-heptanol:
The root word -hept indicates that the main carbon chain has seven carbons.
-ol suffix indicates the presence of alcohol functional group at third carbon.
The 6-methyl prefix indicates the presence of methyl group as the substituent at the sixth position of the main carbon chain.
The structure of 6-methyl-3-heptanol is shown below:
The structure of trans-2-methyl cyclohexanol is shown below:
Andy needs to determine the freezing point depression of 30.0 mL of 0.50 m AlCl3 aqueous solution. When dissolved, AlCl3 dissociates into Al3 and Cl-. Andy realizes that he may need to reduce the effect of ion-pairing in his 0.50 m AlCl3 aqueous solution. Which of the following would reduce the ion-pairing effect in his AlCl3 solution?A. Add some solid AICIz to his solution.B. Add some water to his solution.C. Use only half of his initial volume.D. Use 45 mL of the 0.50 m AlCl3 solution.
Answer:
Add some water to his solution
Explanation:
Ion pair effect refers to strong electrostatic interaction between oppositely charged ions in solution. Such strong interaction affects solute- solvent interaction when an ionic substance is dissolved in water.
High solute concentration may lead to ion-pair effect. Hence, the ion pair effect may be minimized by adding more water (decreasing the concentration of the solution).
To reduce the ion- pair effect, Andy needs to add some water to his solution (dilution).
The activity that would reduce the ion-pairing effect in his AICI₃ solution is : ( B ) add some water to his solution
Ion pair effectIon pair effect is a strong electrostatic interaction seen between ions with opposite charges, when an ionic substance is been dissolved in a solvent such as water this effect will affect the dissolution of the substance.
High concentration of the solute in a solution also leads to the ion pair effect therefore for Andy to reduce the ion-pairing effect in his solution he has to add more water to reduce the concentration of the solute.
Hence we can conclude that The activity that would reduce the ion-pairing effect in his AICI₃ solution is to add some water to his solution
Learn more about ion pair effect : https://brainly.com/question/24100697
pasagot po please!!
science po ito pasagot po matino need ko po!!
Explanation:
Efficiency = (output/input)×100%
70% = output/(800 W)
which means
output = 0.70×(800 W) = 560 W
Discuss the unique properties of carbon as a group 4a element
Answer:
Carbon is dull, have a low density, and are poor conductors of heat.
Explanation:
Carbon is a non-metal, therefore bearing properties of a non-metal element.
How to find the number of protons
Answer:
No of protons is equal to the atomic number.
Answer:
atomic number
Explanation:
g The boiling of water is a Question 4 options: chemical and physical damage chemical change because a gas (steam) is given off chemical change because heat is needed for the process to occur physical change because the water merely disappears physical change because the gaseous water is chemically the same as the liquid
Answer:
physical change because the gaseous water is chemically the same as the liquid
Explanation:
Matter can be defined as anything that has mass and occupies space. Any physical object that is found on earth is typically composed of matter. Matter are known to be made up of atoms and as a result has the property of existing in states.
Generally, matter exists in three (3) distinct or classical phases and these are; solid, liquid and gas.
A physical change can be defined as a type of change that only affects the physical form of a chemical substance (matter) without having any effect on its chemical properties. Thus, a physical change would only affect the physical appearance and properties of a chemical substance (matter) but not its chemical properties.
This ultimately implies that, a physical change result in a change of matter from one form or phase (liquid, solid or gas) to another without a corresponding change in chemical composition.
Hence, the boiling of water is considered to be a physical change because the gaseous water is chemically the same as the liquid i.e there isn't any changes in chemical composition of water when boiling.
You decide to share some sugar sweetened fruit juice with your friend. You divide the fruit equally into two glasses. Then an additional equal volume of water is added to glass 1. Which glass would have the lower molarity?
Answer:
Glass 1
Explanation:
Molarity is measured in moles of substance per liter.
For the sake of calculations, let's say that each glass contains 1 mole of juice and 1 liter after it is divided between the glasses. If you add an equal amount of water to glass 1 ( another liter), you now have:
Glass 1 = 1 mole / 2 liters = 0.5 M
Glass 1 = 1 mole/ 1 liter = 1 M
So glass 1 will have a lower molarity
heating, the particle _______________ increases as more __________ __________ is added
Answer: what are the choices?!.
Explanation:
A student is adding DI water to a volumetric flask to make a 50% solution. Unfortunately, he was not paying attention and filled the flask past the calibration mark. Instead of starting over, the student decides to continue with the experiment. How will the student's results be affected by his mistakes
Answer:
His results will be skewed because there was more water than stock solution. Which would cause the percentage solution to be less than 50% therefore the density would be less than the actual value.
Explanation:
The solution will have percentage less than that of 50%. Therefore the density would be less than the actual value.
Suppose there should be 50 mL of the solution, and he added 60 mL. So 10 mL of the solution is added more.
Suppose the mass of the solute is m.
Originally, the density is = [tex]$\frac{m}{50}$[/tex] [tex]\left(\frac{\text{mass}}{\text{volume}}\right)[/tex]
Now after adding extra 10 mL , the density becomes [tex]$\frac{m}{60}$[/tex].
Therefore, [tex]$\frac{m}{50}>\frac{m}{60}$[/tex]
So the density decreases when we add more solution.
A crop is sprayed with a pesticide to prevent infestation and damage from insects. However, the next season the same pesticide fails to prevent the insects from damaging the crop. Why
Answer:
Farmers spray to mitigate crop damage caused by pests. A pest is any biological organism, including weeds, pathogens, and arthropods, that interferes with the production of crops affecting quality and/or yield. ... Pesticides work in many different ways by affecting their target, whether it be a weed, pest, or disease.
Explanation:
this is my answer❤︎
In a titration to find the concentration of 30ml of a H2SO4 solution, a student found that 40ml of 0.2M KOH solution was needed to reach the endpoint. What's the concentration of the H2SO4?
Question 21 options:
A) 0.27M
B) 0.53M
C) 0.4M
D) 1.1M
Answer:
it's B
Explanation:
Write the balanced equation: H2SO4 + 2KOH → K2SO4 +2H2O. So 2(moles KOH) = (moles H2SO4); 2(volume KOH)(concentration KOH) = (volume H2SO4)(concentration H2SO4); 2(40ml)(0.2M) = (30ml)(x); x = 0.53M
The concentration of H₂SO₄ solution is equal to 0.133 M.
What is a neutralization reaction?A neutralization reaction can be described as a chemical reaction in which an acid and base react together to form respective salt and water. When a strong acid such as HCl will react with a strong base such as NaOH the salt can be neither acidic nor basic.
When H₂SO₄ (a strong acid) reacts with KOH, the resulting salt will be K₂SO₄ and water.
H₂SO₄ + 2KOH → K₂SO₄ + 2H₂O
Given, the concentration of KOH solution = 0.2 M
The volume of the KOH solution = 40 ml = 0.040 ml
The number of moles of KOH, n = M × V = 0.2 × 0.04 = 0.008 mol
The volume of the H₂SO₄ = 30 ml = 0.03 L
The number of moles of H₂SO₄, n = 0.008/2 = 0.004 mol
The concentration of H₂SO₄ solution = 0.004/0.03 = 0.133 M
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Which of the following can be mixed in solution with NH3 to make a buffer?
Answer:
c. NaOH
Explanation:
just took the quiz
I am holding a balloon containing 439 mL of gas over my fireplace. The temperature and pressure of the gas inside the balloon is 317.15 K and 0.959 atm, respectively. Suppose I don't want the pressure to change, but I want to the volume to go down to 0.378 L. What is the temperature that I need to reach when I cool down the balloon?
To what temperature (in Celsius) must the balloon be cooled to reduce its volume to 0.378 L if the pressure doesn't change (remained constant)?
Answer:
-0.08 °C
Explanation:
We can solve this problem by using Charles' law, which states that at constant pressure:
V₁T₂ = V₂T₁Where in this case:
V₁ = 439 mLT₂ = ?V₂ = 0.378 L ⇒ 0.378 * 1000 = 378 mLT₁ = 317.15 KWe input the data:
439 mL * T₂ = 378 mL * 317.15 KAnd solve for T₂:
T₂ = 273.08 KFinally we convert 273.08 K to Celsius:
273.08 K - 273.16 = -0.08 °CToothpastes containing sodium hydrogen carbonate (sodium bicarbonate) and hydrogen peroxide are widely used. Write Lewis structures for the hydrogen carbonate ion and hydrogen peroxide molecule, with resonance forms where appropriate.
Answer:
See explanation and images attached
Explanation:
The first image shows the structure of hydrogen peroxide. It does not exist as resonance structures. The structure and properties of the molecule can wholly be explained on the basis of a single Lewis structure.
However, the structure of the bicarbonate ion in sodium bicarbonate can not be completely described by a single Lewis structure. Hence, two resonance structures are shown for the bicarbonate ion. In each case, Na^+ is the counter ion.
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:
Which of the following is considered a standard unit of length in the United States?
O square inch
O acre
O cubic yard
O yard
Answer:
Yard . I hope this helped:))
A coffee cup has a heat capacity of 62.6 - If the coffee cup's temperature increases by 1.20°C, how much heat has it
absorbed?
Select the correct answer below:
?
Answer:
75.12 J
Explanation:
Applying,
Q = CΔT................ equation 1
Where Q = amount of heat, C = Heat capacity, ΔT = temperature rise.
From the question,
Given: C = 62.6 J/K, ΔT = 1.20°C
Substitute these values into equation 1
Q = 62.6(1.20)
Q = 75.12 J
Hence the amount of heat it absorbed is 75.12 J
Balance this equation, _AlCl3 + _NaOH → _Al(OH)3 + _NaCl
Answer:
AlCl3 + 3NaOH ———>Al(OH)3 + 3NaCl
The pH of a certain orange juice is 3.33.Calculate the +ion concentration.
Answer:
[tex]4.67\times 10^{-4}[/tex]
Explanation:
Given that,
The pH of a certain orange juice is 3.33.
We need to find the +ion concentration.
We know that,
[tex]pH=-log[H^+][/tex]
So,
[tex]3.33=-log[H^+]\\\\\[H^+=10^{-3.33}\\\\=4.67\times 10^{-4}[/tex]
So, the +ion concentraion is equal to [tex]4.67\times 10^{-4}[/tex].
Which of the following is the most plausible explanation for the fact that the saponification of the triacylglycerol in the passage resulted in four different fatty acid salts?
a. The triacylglycerol molecule consisted of four different fatty acid units.
b. Glycerol was transformed into a fatty acid salt under the reaction conditions.
c. One of the fatty acid salts was unsaturated, and it completely isomerized under the reaction conditions.
d. One of the fatty acid salts was unsaturated, and a small percentage isomerized under the reaction conditions.
Answer: The correct option is C (One of the fatty acid salts was unsaturated, and it completely isomerized under the reaction conditions).
Explanation:
Fats and oils belongs to a general group of compounds known as lipids. Fatty acids are weak acid and are divided into two:
--> Saturated fatty acids: These have NO double bonds in their hydrocarbon chain, and
--> Unsaturated fatty acids: These have one or more double bonds in their hydrocarbon chain.
SAPONIFICATION is defined as the process by which fats and oil is hydrolyzed with caustic alkali to yield propane-1,2,3-triol and the corresponding sodium salt of the component fatty acids. During this process, One hydroxide ion is required to hydrolyze one ester linkage of a triacylglycerol molecule. Because there are three ester linkages in a triacylglycerol, three equivalents of sodium hydroxide will be needed to completely saponify the triacylglycerol. This explains the reason why saponification of the triacylglycerol iresulted in four different fatty acid salts.
An atom of 24/11 na decays by gamma decay which atom is left after the decay
Answer:
Hello There!!
Explanation:
The atom is still 24Na.
hope this helps,have a great day!!
~Pinky~