Answer:
Contributes to the buildup of plaque in the walls of arteries. This plaque buildup can narrow the arteries and increase the risk of heart disease, heart attack, and stroke.
Suppose that the microwave radiation has a wavelength of 12.4 cm. How many photons are required to heat 205 mL of coffee from 25.0 ∘C to 62.0 ∘C ? Assume that the coffee has the same density, 0.997 g/mL, and specific heat capacity, 4.184 J/(g⋅K), as water over this temperature range.
Answer:
To calculate the number of photons required to heat the coffee, we can follow these steps:
Calculate the mass of the coffee using its volume and density:
mass = volume x density = 205 mL x 0.997 g/mL = 204.185 g
Calculate the amount of heat required to raise the temperature of the coffee using its mass, specific heat capacity, and temperature change:
q = m x c x ΔT = 204.185 g x 4.184 J/(g⋅K) x (62.0 - 25.0) °C = 32289.6 J
Calculate the energy of each photon using the formula E = hc/λ, where h is Planck's constant, c is the speed of light, and λ is the wavelength of the microwave radiation:
E = (6.626 x 10^-34 J⋅s) x (3.00 x 10^8 m/s) / (0.124 m) = 5.067 x 10^-23 J
Calculate the number of photons required to deliver the amount of energy needed to heat the coffee:
number of photons = q / E = 32289.6 J / 5.067 x 10^-23 J = 6.368 x 10^25 photons
Therefore, approximately 6.368 x 10^25 photons are required to heat 205 mL of coffee from 25.0 ∘C to 62.0 ∘C using microwave radiation with a wavelength of 12.4 cm.
Draw the MO diagram for the superoxide ion, O2-. Which statement is true regarding the superoxide ion?
A. The superoxide ion is diamagnetic.
B. It is attracted to a magnetic field.
C. Its MO diagram has two unpaired electrons.
D. It has a bond order of 2.
A. The superoxide ion is diamagnetic.
This statement is false. According to Hund's rule, electrons prefer to occupy separate orbitals if possible, which means that the two unpaired electrons in the π* orbital will have parallel spins, making the superoxide ion paramagnetic.
B. It is attracted to a magnetic field.
This statement is true. As a paramagnetic species, the superoxide ion will be attracted to a magnetic field.
C. Its MO diagram has two unpaired electrons.
This statement is true. The π* orbital contains two electrons with parallel spins, which means they are unpaired.
D. It has a bond order of 2.
This statement is also true. The bond order can be calculated by taking the difference between the number of electrons in the bonding orbitals (σ and π) and the number of electrons in the antibonding orbitals (σ* and π*), and then dividing by two. In this case, the bonding orbitals have 6 electrons and the antibonding orbitals have 4 electrons, giving a bond order of 1. (6 - 4) / 2 = 1. However, because the superoxide ion is a radical species with unpaired electrons, we need to add one more electron to the MO diagram to get the correct bond order. The total number of valence electrons in the superoxide ion is 16 (6 from each oxygen atom, plus the extra electron), which gives a bond order of 2. (8 - 6) / 2 = 1.
Learn more about diamagnetic here:
https://brainly.com/question/15462756
#SPJ1
Base is added to 200. mL of a 2.0 M solution acid solution. If 400 mL of base is added to titrate the acid solution. What is the concentration of the base?
Answer:
To solve this problem, we need to use the concept of stoichiometry and the equation for neutralization reactions. The balanced equation for the neutralization of an acid and a base is: acid + base → salt + water In this case, we know that 200 mL of a 2.0 M acid solution is titrated with 400 mL of a base solution. Let's call the concentration of the base solution "x". To find the concentration of the base solution, we can use the following equation: moles of acid = moles of base The number of moles of acid can be calculated as follows: moles of acid = volume of acid × concentration of acid moles of acid = 0.2 L × 2.0 mol/L moles of acid = 0.4 mol Since the acid and base react in a 1
What is the balanced equation of KOH + HCl -> KCl + H2O
I am not sure if this will help you but I tried.
Explanation,
This is already a balanced equation because there are same number of atoms for the same type of elements on both sides of the equation.
How can a good or service affect culture?
Answer:
Explanation:
establish a direct relationship between organizational culture and effectiveness
Can somebody please help me solve this? I would very much appreciate it.
a. Balanced equation for the decomposition of sodium bicarbonate by heating is:
2 NaHCO3(s) → Na2CO3(s) + CO2(g) + H2O(g)
b. To heat the mixture, the student can use a Bunsen burner or a hot plate in a fume hood to prevent the release of any harmful gases. The mixture should be heated until there is no more mass loss. To determine the mass loss, the student can weigh the vial and its contents before and after heating. The difference between the two weights will be the mass loss.
c. The student can know that all the sodium bicarbonate has been decomposed when there is no more mass loss. The heating should be continued until the mass of the vial and its contents remains constant.
d. The mass loss of 2.28 g is due to the decomposition of 1 mol of NaHCO3, which has a molar mass of 84 g/mol. Therefore, the original mixture contained 2.28/84 = 0.027 mol of NaHCO3. The mass of Na2CO3 in the mixture can be calculated as follows:
mass of Na2CO3 = mass of mixture - mass loss = 14.00 g - 2.28 g = 11.72 g
The molar mass of Na2CO3 is 106 g/mol, so the number of moles of Na2CO3 in the mixture is:
moles of Na2CO3 = mass of Na2CO3/molar mass of Na2CO3 = 11.72 g/106 g/mol = 0.111 mol
The percentage of Na2CO3 in the original mixture is:
% Na2CO3 = (moles of Na2CO3/total moles of carbonate) x 100% = (0.111/0.138) x 100% = 80.4%
e. To determine which is the limiting reactant, we need to compare the number of moles of NaHCO3 and Na2CO3 in the mixture. We know that the mixture contained 0.027 mol of NaHCO3 and 0.111 mol of Na2CO3. Since the balanced equation shows that 2 moles of NaHCO3 produce 1 mole of Na2CO3, the number of moles of Na2CO3 that can be produced from 0.027 mol of NaHCO3 is:
moles of Na2CO3 = 0.027 mol NaHCO3 x (1 mol Na2CO3/2 mol NaHCO3) = 0.0135 mol Na2CO3
Since the actual amount of Na2CO3 in the mixture is greater than 0.0135 mol, we can conclude that NaHCO3 is the limiting reactant, and Na2CO3 is in excess.
d.
Mass of NaHCO3 = 2.28 g / 84 g/mol = 0.027 mol NaHCO3
Mass of Na2CO3 = 14.00 g - 2.28 g = 11.72 g
Moles of Na2CO3 = 11.72 g / 106 g/mol = 0.111 mol Na2CO3
Total moles of carbonate = moles of NaHCO3 + moles of Na2CO3 = 0.027 mol + 0.111 mol = 0.138 mol
% Na2CO3 = (moles of Na2CO3 / total moles of carbonate) x 100% = (0.111 mol / 0.138 mol) x 100% = 80.4%
e.
Moles of Na2CO3 that can be produced from 0.027 mol of NaHCO3 = 0.027 mol NaHCO3 x (1 mol Na2CO3 / 2 mol NaHCO3) = 0.0135 mol Na2CO3
Since the actual amount of Na2CO3 in the mixture (0.111 mol) is greater than 0.0135 mol, NaHCO3 is the limiting reactant, and Na2CO3 is in excess.
ChatGPT
A 1.000-g sample of iron metal reacted with sulfite powder to give 1.574 g of product. Calculate the empirical formula of iron sulfide.
The empirical formula of iron sulfide is FeS. The empirical formula represents the simplest whole number ratio of atoms in the compound, but it may not represent the actual molecular formula.
What is Empirical Formula?
The empirical formula of a chemical compound is the simplest whole number ratio of atoms of each element present in the compound. It can be determined from the mass or percentage composition of the elements in the compound.
We can use the given mass of iron and the mass of the product formed to determine the amount of sulfur that reacted with the iron.
First, we need to determine the mass of sulfur in the product:
mass of sulfur = mass of product - mass of iron
mass of sulfur = 1.574 g - 1.000 g
mass of sulfur = 0.574 g
Next, we can use the mass of iron and sulfur to calculate the number of moles of each element:
moles of iron = mass of iron / molar mass of iron
moles of iron = 1.000 g / 55.85 g/mol
moles of iron = 0.0179 mol
moles of sulfur = mass of sulfur / molar mass of sulfur
moles of sulfur = 0.574 g / 32.06 g/mol
moles of sulfur = 0.0179 mol
The mole ratio of iron to sulfur in the compound can be determined by dividing each value by the smaller of the two:
mole ratio of iron to sulfur = moles of iron / moles of sulfur
mole ratio of iron to sulfur = 0.0179 mol / 0.0179 mol
mole ratio of iron to sulfur = 1:1
Learn more about Empirical Formula from the given link
https://brainly.com/question/1603500
#SPJ1
If 39.5 g AlCl3 is produced, how many grams of HCl was used in the reaction
64.8 g of HCl was used in the reaction to produce 39.5 g of AlCl3.
What is Reaction?
A reaction is a process in which one or more substances are chemically transformed into one or more new substances. It involves the breaking of chemical bonds in the reactants and the formation of new bonds in the products. Reactions can occur spontaneously, as in the case of a burning match or rusting iron, or they may require the addition of energy, as in the case of photosynthesis or the combustion of fossil fuels.
The balanced chemical equation for the reaction between Al and HCl is:
2Al(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2(g)
From the equation, we see that 6 moles of HCl are required to produce 1 mole of AlCl3. We can use this ratio to calculate the moles of HCl required to produce 39.5 g of AlCl3.
First, we need to calculate the molar mass of AlCl3:
AlCl3: Al = 26.98 g/mol, Cl = 35.45 g/mol x 3 = 106.35 g/mol
Molar mass of AlCl3 = 26.98 + 106.35 = 133.33 g/mol
Now we can use the molar mass of AlCl3 to convert the mass of AlCl3 produced to moles:
39.5 g AlCl3 / 133.33 g/mol = 0.296 moles AlCl3
Finally, we can use the mole ratio from the balanced equation to calculate the moles of HCl:
6 moles HCl / 1 mole AlCl3 = x moles HCl / 0.296 moles AlCl3
x = 6 x 0.296 = 1.776 moles HCl
To convert this to grams, we can use the molar mass of HCl:
HCl: H = 1.01 g/mol, Cl = 35.45 g/mol
Molar mass of HCl = 1.01 + 35.45 = 36.46 g/mol
1.776 moles HCl x 36.46 g/mol = 64.8 g HCl
Learn more about Reaction from given link
https://brainly.com/question/25769000
#SPJ1
Which is more abundant, Organic compounds or Inorganic compounds?
Answer:
inorganic compounds are more abundent
How do ionic differ from covalent bonds?
_____________________________________________________
I hope you find this easy to understand....
If you find this really useful, please give me a brainliest.
Have Any questions? write in the comments below.
The graph shows the reaction AB → A+B+ heat.
If the graph indicates how quickly the reaction is progressing,
then the concentration of which component of the equation is
shown in the graph?
Oreactant
O product A
O product B
O heat
Help asap 20pts
The graph shows the reaction AB → A+B+ heat.
If the graph indicates how quickly the reaction is progressing,
then the concentration of which component of the equation is
shown in the graph?
Answer: reactant.
The graph shows the progress of a reaction over time, and the concentration of the reactant (AB) decreases while the concentration of the products (A and B) increases.
Therefore, the concentration of the reactant (AB) is shown in the graph. As the reaction progresses, the concentration of the reactant decreases and the concentration of the products increases until the reaction is complete, at which point the concentration of the reactant will be zero and the concentration of the products will be at a maximum.
The heat released or absorbed during the reaction is not shown in the graph, as it is not a component that changes concentration over time.
To know more about reactant, visit:
https://brainly.com/question/17096236
#SPJ1
Ethanol is a chemical that can be synthetically produced from the sugars of plants, such as corn, using the fermentation reaction shown below. The reaction shows that sugar from plants can be broken down into ethanol and carbon dioxide, releasing heat. sugar → ethanol + carbon dioxide + heat In the United States, the sugar used to produce ethanol is commonly gained from corn—the same type of corn that is used for some foods, like corn flour, corn syrup, and corn oil. The ethanol can then be used as fuel in automobiles. Scientists and engineers are working to develop ways to replace corn with a different plant, such as switchgrass, in the production of ethanol. This is largely because using corn to produce ethanol could cause a problem for society. Which statement describes this problem? A. Grass resources are scarce and could be used up if harvested to produce ethanol. B. Corn grown for ethanol could take up field space that had been used to grow corn for food. C. Chemical processes that can transform corn's sugars into ethanol do not exist. D. Chemical processes that can release the chemical energy in ethanol do not exist.
Answer: Pretty tough one, but I would have to say B.
Explanation: If we plant Corn to use as fuel, the economy will need more Ethanol to fuel automobiles. This means that less edible corn will be planted, and more Ethanol Corn will be planted. Hope this helps!
Predicting Products: Ga2S3 + CaBr2. (2 and 3 are coefficients)
(if you could just write it out it’d be helpful)
The product of Ga₂S₃ + CaBr₂ is CaS and GaBr₃ , where 2 and 3 are stoichiometric coefficients. The balanced chemical reaction is 2Ga₂S₃ + 6CaBr → 6CaS + 2GaBr₃. The sum of the coefficients is 5.
What is balanced chemical reaction?An equation for a chemical reaction is said to be balanced if both the reactants and the products have the same number of atoms and total charge for each component of the reaction. In other words, both sides of the reaction have an equal balance of mass and charge.
The reactants and products of a chemical reaction are listed in an imbalanced chemical equation, but the amounts necessary to meet the conservation of mass are not specified. For instance, the mass balance of the following equation for the reaction between iron oxide and carbon to produce iron and carbon dioxide is off:
Fe₂O₃ + C → Fe + CO₂
The equation must be balanced so that each type of atom appears in equal amounts on both the left and right sides of the arrow. This is accomplished by altering the compounds' coefficients (numbers placed in front of compound formulas). In this example, the subscripts (tiny numbers to the right of some atoms, including iron and oxygen) are never altered. The chemical identification of the compound would change if the subscripts were changed.
2 Fe₂O₃ + 3 C → 4 Fe + 3 CO₂
To know more about conservation of mass, visit:
https://brainly.com/question/23218279
#SPJ1
A gas sample contains 4.4 g of CO2 and 2 g of He. What is the volume of the sample at STP?
Explanation:
At STP (standard temperature and pressure), the temperature is 273.15 K and the pressure is 1 atm. We can use the ideal gas law to calculate the volume of the gas sample:
PV = nRT
where P is the pressure, V is the volume, n is the number of moles of gas, R is the ideal gas constant (0.08206 L·atm/mol·K), and T is the temperature.
First, we need to calculate the number of moles of each gas present in the sample. The molar mass of CO2 is 44.01 g/mol, and the molar mass of He is 4.00 g/mol.
moles of CO2 = mass of CO2 / molar mass of CO2
moles of CO2 = 4.4 g / 44.01 g/mol
moles of CO2 = 0.0998 mol
moles of He = mass of He / molar mass of He
moles of He = 2 g / 4.00 g/mol
moles of He = 0.5 mol
The total number of moles in the gas sample is:
total moles = moles of CO2 + moles of He
total moles = 0.0998 mol + 0.5 mol
total moles = 0.5998 mol
Now, we can use the ideal gas law to calculate the volume of the gas sample:
V = nRT/P
V = (0.5998 mol)(0.08206 L·atm/mol·K)(273.15 K)/(1 atm)
V = 12.96 L
Therefore, the volume of the gas sample at STP is approximately 12.96 L.
The term used to describe the non-living parts of an eco system
Answer:
Abiotic Factor
Explanation:
Is a non-living part of an ecosystem that shapes its enviroment.
When quartz undergoes metamorphism (exposure to extreme heat and pressure), what kind of metamorphic rock can it become?
What are the common reducing agent
Answer: might be lack of taste, education, and good manners
Explanation:
O₂(g) + 2 H₂(g) →2 H₂O
The rate law for this reaction is second order in H₂ and first order in O₂. Write the rate
law.
If the rate constant for this reaction at 1000 K is 6.0 x 104 M²s¹, what is the reaction
rate when [0₂] = 0.055 M and [H₂] = 0.015 M?
Answer:
9.94 x 10^-6 M/s
Explanation:
The rate law for the given reaction is:
Rate = k[O₂][H₂]²
where k is the rate constant, [O₂] is the concentration of O₂, and [H₂] is the concentration of H₂.
Using the given values, we can substitute them into the rate law and solve for the reaction rate:
Rate = (6.0 x 10^4 M²s^-1) x (0.055 M) x (0.015 M)²
Rate = 9.94 x 10^-6 M/s
Therefore, the reaction rate when [O₂] = 0.055 M and [H₂] = 0.015 M is 9.94 x 10^-6 M/s.
A sample of gas has an initial pressure of 740 mmHg and an initial volume of 32.0 L. If the volume is changed to 21.8 L, what is the new pressure? Assume temperature and amount remain constant
Answer:
1086.2 mmHg
Explanation:
P1×V1=P2×V2
740mmHg×32.0L=P2×21.8L
23680L mmHg= P2×21.8L
divide both sides by 21.8L
1086.2mmHg=P2
A student mixes four reagents together, thinking that the solu- tions will neutralize each other. The solutions mixed together are 50.0 mL of 0.100 M hydrochloric acid, 100.0 mL of 0.200 M of nitric acid, 500.0 mL of 0.0100 M calcium hydroxide , and 200.0 mL of 0.100 M rubidium hydroxide . Is the resulting solution neutral ? If not , calculate the concentration of excess H^+ or OH ions left in solution.
To determine whether the resulting solution is neutral, we need to calculate the moles of H+ and OH- ions present in the solution and compare their concentrations.
First, we can calculate the moles of H+ ions present in the solution by using the equation:
moles H+ = volume (L) x concentration (mol/L)
moles H+ = (50.0 mL + 100.0 mL) x 0.100 mol/L = 15.0 x 10⁻³ mol
Next, we can calculate the moles of OH- ions present in the solution by using the equation:
moles OH- = volume (L) x concentration (mol/L)
moles OH- = (500.0 mL + 200.0 mL) x 0.0100 mol/L = 7.0 x 10⁻³ mol
Since the number of moles of H+ and OH- ions are not equal, the resulting solution is not neutral. To calculate the concentration of excess H+ or OH- ions left in solution, we need to determine which ion is present in excess.
Since HCl and HNO3 are strong acids and Ca(OH)2 and RbOH are strong bases, we can assume that all of the H+ and OH- ions from the acids and bases will react completely to form water. Therefore, we can calculate the excess H+ or OH- ions by comparing the moles of H+ and OH- ions present in the solution.
moles H+ - moles OH- = (15.0 x 10⁻³mol) - (7.0 x 10⁻³ mol) = 8.0 x 10⁻³ mol
Since the moles of H+ ions are greater than the moles of OH- ions, there is an excess of H+ ions in the solution. To calculate the concentration of excess H+ ions, we can divide the moles of H+ ions by the total volume of the solution in liters:
[H+] = moles H+ / volume (L)
[H+] = 8.0 x 10⁻³ mol / (50.0 mL + 100.0 mL + 500.0 mL + 200.0 mL) = 3.2 x 10⁻⁴M
Therefore, the resulting solution is not neutral, and it has an excess of H+ ions with a concentration of 3.2 x 10⁻⁴ M.
To know more about concentration, visit:
https://brainly.com/question/10725862
#SPJ1
To determine the mass of 4.35 moles of potassium chloride
The mass of 4.35 moles of potassium chloride is 324.14 grams. Potassium chloride (KCl) is a chemical compound made up of potassium and chlorine.
Potassium chloride (KCl) is a chemical compound composed of potassium and chlorine. It is commonly used as a salt substitute for people on low-sodium diets, as well as a fertilizer, a source of potassium in food additives, and a component of some medical solutions. Potassium chloride can also be used in the production of various chemicals, including explosives and pharmaceuticals.
The molar mass of potassium chloride (KCl) is 74.55 g/mol (39.10 g/mol for K and 35.45 g/mol for Cl).
To calculate the mass of 4.35 moles of KCl, we can use the following formula:
mass = moles × molar mass
So, the mass of 4.35 moles of KCl is:
mass = 4.35 moles × 74.55 g/mol
mass = 324.14 g
To know more about potassium chloride please refer: https://brainly.com/question/22528097
#SPJ1
A 1.0 L of a 6.0 M solution of HCl acid is titrated with a 0.2 M basic solution. How much base is needed to reach its titration endpoint?
(I only have four more questions to ask lol)
Answer:
No worries, happy to help! To find out how much base is needed to reach the titration endpoint, we need to use the balanced chemical equation for the reaction between HCl and the basic solution, and the stoichiometry of the reaction. The balanced chemical equation is: HCl + NaOH → NaCl + H2O From the equation, we can see that 1 mole of HCl reacts with 1 mole of NaOH. We also know that the initial volume of HCl solution is 1.0 L, and the initial concentration is 6.0 M. This means we have: moles of HCl = volume x concentration = 1.0 L x 6.0 mol/L = 6.0 mol To reach the titration endpoint, we need to add enough NaOH solution to completely neutralize all
when you prepare a kettle of stew over a camp fire the stew is warmed in a variety of ways example the combination
A bonfire to heat a stew kettle. The stew is warmed using a variety of techniques, such as the combo, when I am close to a fire, you are not mainly receiving heat from hot air.
In what way does the heat get transferred by sitting next to the fire?The method by which heat is transmitted to a person sitting near a fire is convection. Convection happens as a method of transfer when heat is transferred from one thing to another body when both bodies are made of different materials.
As we feel the heat of a campfire, convection currents are heating your palm. Different heat sources, like radiation, cause heat to manifest. However, a powerful convection current rises in your direction as you elevate your palm over a fire.
When I sit beside a campfire, how does its hot air heat me?Learn more about convection
https://brainly.com/question/4138428
#SPJ9
What is the working mechanism in the pH meter? Briefly describe it.
why is grass green why not pink or blue?
Answer:
There is a tint or pigment in the grass that gives it the color green called chlorophyll. That is used during the photosynthesis cycle.
Explanation:
You're welcome.
16. How many molecules are present in 3.0 X 102 grams of calcium
carbonate? [Calcium - 40 g/m;Carbon - 12g/m. Oxygen - 16 g/m]
A) 6.02 X 1023
B 81.1 X 1023.
C) 1.81 X 1024
To solve this problem, we need to use the concept of Avogadro's number and molecular weight.
The molecular weight of calcium carbonate (CaCO3) can be calculated as follows:
Calcium (Ca) atomic weight = 40 g/molCarbon (C) atomic weight = 12 g/molOxygen (O) atomic weight = 16 g/molMolecular weight of CaCO3 = (1 x 40) + (1 x 12) + (3 x 16) = 100 g/molNow, we can calculate the number of molecules in 3.0 x 10^2 grams of CaCO3 as follows:
Convert the mass of CaCO3 to moles using the formula:moles = mass / molecular weight
moles = 3.0 x 10^2 g / 100 g/mol
moles = 3.0 x 10^0 mol
Use Avogadro's number to calculate the number of molecules:number of molecules = moles x Avogadro's number
number of molecules = 3.0 x 10^0 mol x 6.02 x 10^23 molecules/mol
number of molecules = 1.806 x 10^24
Therefore, the answer is C) 1.81 x 10^24.
help me plssss i beg i beg
To calculate the percent yield, we need to compare the actual yield obtained to the theoretical yield that could be obtained under ideal conditions.
First, we need to find the balanced chemical equation for the reaction:
2 Cu + S → Cu2S
From the equation, we see that 2 moles of copper are needed to produce 1 mole of copper(1) sulfide.
Given that 0.0970 moles of copper was used, the theoretical yield of copper(1) sulfide can be calculated as follows:
1 mol Cu2S = 2 × 63.55 g Cu + 32.07 g S = 159.17 g Cu2S
0.0970 mol Cu × (159.17 g Cu2S / 2 mol Cu) = 7.94 g Cu2S (theoretical yield)
The actual yield obtained is given as 2.64 g Cu2S. Therefore, the percent yield can be calculated as:
percent yield = (actual yield / theoretical yield) × 100%
percent yield = (2.64 g / 7.94 g) × 100%
percent yield = 33.2%
The percent yield for the reaction is 33.2%. This means that only 33.2% of the expected yield of copper(1) sulfide was obtained under the given conditions.
To know more about percent yield, visit:
https://brainly.com/question/17042787
#SPJ1
How is an ellipse described numerically?
An ellipse is described numerically by its mathematical equation, which includes the center, major and minor axes, and values of a and b. The foci of ellipse can also be calculated from its equation.
How is an ellipse described numerically?An ellipse is a geometric shape that is defined by two points called foci and a constant sum of distances from any point on the ellipse to the two foci. This constant sum is called the major axis or the length of the ellipse, while the distance between the center of ellipse and the foci is called the minor axis or width of the ellipse.
To describe an ellipse numerically, we use its mathematical equation, which is in the form of: ((x-h)² / a²) + ((y-k)² / b²) = 1
(h, k) is center of ellipse
a is length of major axis divided by 2; b is length of minor axis divided by 2
The values of a and b determine the shape of ellipse. If a = b, the ellipse is a circle. If a > b, ellipse is stretched horizontally and is called an oblong ellipse. If a < b, ellipse is stretched vertically and is called a flat ellipse.
Two foci of ellipse can also be calculated using: c = √(a² - b²)
c is distance from the center of the ellipse to either of the foci.
To know more about ellipse, refer
https://brainly.com/question/9702250
#SPJ1
How many grams of dry NH4Cl need to be added to 2.50 L of a 0.300 M solution of ammonia, NH3 , to prepare a buffer solution that has a pH of 8.51? Kb for ammonia is 1.8×10−5 .
The correct answer To prepare a buffer solution with a pH of 8.51, we need to use the Henderson-Hasselbalch equation:
pH = pKa + log([base]/[acid] where pKa is the dissociation constant for the base, [base] is the concentration of the base, and [acid] is the concentration of the conjugate acid. For the ammonia/ammonium ion buffer system, the equation is: NH3 + H2O ⇌ NH4+ + OH- The equilibrium constant expression for this reaction is: Kb = [NH4+][OH-]/[NH3] We are given the Kb value as 1.8 x 10^-5, and we can use it to find the concentration of OH- in the buffer solution: Kb = [NH4+][OH-]/[NH3] 1.8 x 10^-5 = [NH4+][OH-]/(0.300 - [NH4+]) Let's assume that the concentration of NH4+ is much less than 0.300 M (which is a reasonable assumption for most buffer solutions). This means that we can approximate the denominator as 0.300 M: 1.8 x 10^-5 = [NH4+][OH-]/0.300 Solving for [OH-], we get: [OH-] = sqrt(Kb*[NH3]) = sqrt(1.8 x 10^-5 * 0.300) = 6.60 x 10^-4 M To find the concentration of NH4+, we can use the Henderson-Hasselbalch equation: pH = pKa + log([base]/[acid]) 8.51 = 9.25 + log([NH4+]/[NH3]) Solving for [NH4+]/[NH3], we get: [NH4+]/[NH3] = 10^(8.51-9.25) = 3.52 x 10^-2 Since we know that the total volume of the buffer solution is 2.50 L, we can use the molarity of NH3 to find the moles of NH3 in the solution: moles of NH3 = 0.300 M x 2.50 L = 0.75 mol We can then use the ratio of NH4+ to NH3 to find the moles of NH4+ in the solution: moles of NH4+ = (3.52 x 10^-2) x (0.75 mol) = 2.64 x 10^-2 mol Finally, we can use the molar mass of NH4Cl (53.49 g/mol) to find the mass of NH4Cl needed to prepare the buffer solution: mass of NH4Cl = moles of NH4Cl x molar mass of NH4Cl To find the moles of NH4Cl, we can use the stoichiometry of the reaction between NH4Cl and NH3: NH4Cl + NH3 → NH4+ + Cl- For every mole of NH4+ in the buffer solution, we need one mole NH4Cl. Therefore moles of NH4Cl = moles of NH4+ = 2.64 x 10^-2 molSubstituting this value into the equation for mass of NH4Cl, we getmass of NH4Cl = (2.64 x 10^-2 mol) x (53.49 g/mol) = 1.41 g Therefore, we need approximately 1.41 grams of dry NH4Cl to add to 2.50 L of a 0.300 M
To learn more about Henderson- click on the link below:
brainly.com/question/29619380
#SPJ1
The particle diagram below represents a solid sample of silver.
Ag
Ag
(Ag
Ag
N
Ag
2.
Ag
4.
(Ag
Ag
Ag
Ag
Ag
(Ag
1. metallic bonding
hydrogen bonding
3. covalent bonding
ionic bonding
Which type of bonding is present when valence electrons move within the sample?
The particle diagram represents a solid sample of silver, which is a metallic element. The type of bonding present when valence electrons move within the sample of silver is 1.) metallic bonding
What is metallic bonding?Metallic bonding is the type of bonding present in metals like silver, where valence electrons move freely throughout the solid sample. Therefore, the type of bonding present when valence electrons move within the sample of silver is metallic bonding.
Metallic bonding is a type of chemical bonding that occurs in metals and alloys. It is a type of bonding where valence electrons are not strongly bound to any one particular atom, but are free to move throughout the entire solid structure.
To know more about metallic bonding, refer
https://brainly.com/question/19023138
#SPJ1