Explanation:
It depends on Mass and Height above ground.
P.E. - mgh
Mark me BrAinLieST.
Please answer Q1, Q2, Q3 and Q4 in great detail. Thank you so much
Q1. State the formula for the energy levels of Hydrogen
Q2. What is the wavelength (in nm) for a transition between:
a) n=1⇒n=6?
b) n=25⇒n=26?
Q3. For a gas temperature of 300K, what is the relative density (between the two states) for each of the transitions in Q2? To two decimal points is sufficient.
Q4. The Lambert-Beers law is:
I(x) = I◦ exp(−nσx)
where n is the density of the absorber, σ(λ) is the wavelength-dependent cross section for absorption, x is the position, I◦ is the initial photon flux, I(x) is the photon flux versus position through the absorber.
Derive the Lambert-Beers law. (State and justify any assumptions.)
Q1. The formula for the energy levels of hydrogen is E = -13.6 eV/n².
Q2. a) The wavelength for the transition between n=1 and n=6 is approximately 93.5 nm. b) The wavelength for the transition between n=25 and n=26 is approximately 29.46 nm.
Q3. For the transitions in Q2, the relative densities are approximately 0.73 and 0.995, respectively.
Q4. The Lambert-Beers law relates the intensity of light transmitted through an absorber to the absorber's density, cross section for absorption, and position within the medium. It is expressed as I(x) = I₀ * exp(-n * σ(λ) * x).
Q1. The formula for the energy levels of hydrogen is given by the Rydberg formula, which is used to calculate the energy of an electron in the hydrogen atom:
E = -13.6 eV/n²
Where:
- E is the energy of the electron in electron volts (eV).
- n is the principal quantum number, which represents the energy level or shell of the electron.
Q2. a) To find the wavelength (in nm) for a transition between n=1 and n=6 in hydrogen, we can use the Balmer series formula:
1/λ = R_H * (1/n₁² - 1/n₂²)
Where:
- λ is the wavelength of the photon emitted or absorbed in meters (m).
- R_H is the Rydberg constant for hydrogen, approximately 1.097 x 10⁷ m⁻¹.
- n₁ and n₂ are the initial and final energy levels, respectively.
Plugging in the values, we have:
1/λ = (1.097 x 10⁷ m⁻¹) * (1/1² - 1/6²)
1/λ = (1.097 x 10⁷ m⁻¹) * (1 - 1/36)
1/λ = (1.097 x 10⁷ m⁻¹) * (35/36)
1/λ = 1.069 x 10⁷ m⁻¹
λ = 9.35 x 10⁻⁸ m = 93.5 nm
Therefore, the wavelength for the transition between n=1 and n=6 in hydrogen is approximately 93.5 nm.
b) Similarly, to find the wavelength (in nm) for a transition between n=25 and n=26 in hydrogen, we can use the same formula:
1/λ = R_H * (1/n₁² - 1/n₂²)
Plugging in the values:
1/λ = (1.097 x 10⁷ m⁻¹) * (1/25² - 1/26²)
1/λ = (1.097 x 10⁷ m⁻¹) * (1/625 - 1/676)
1/λ = (1.097 x 10⁷ m⁻¹) * (51/164000)
1/λ = 3.396 x 10⁴ m⁻¹
λ = 2.946 x 10⁻⁵ m = 29.46 nm
Therefore, the wavelength for the transition between n=25 and n=26 in hydrogen is approximately 29.46 nm.
Q3. To determine the relative density for each of the transitions in Q2, we need to calculate the ratio of the photon flux between the two states. The relative density is given by the equation:
Relative Density = (I(x2) / I(x1))
Where I(x2) and I(x1) are the photon fluxes at positions x2 and x1, respectively.
For a gas temperature of 300K, the relative density is proportional to the Boltzmann distribution of states, which is given by:
Relative Density = exp(-ΔE/kT)
Where ΔE is the energy difference between the two states, k is the Boltzmann constant (approximately 1.38 x 10⁻²³ J/K), and T is the temperature in Kelvin.
a) For the transition between n=1 and n=6, the energy difference is:
ΔE = E₁ - E₂ = (-13.6 eV / 1²) - (-13.6 eV / 6²)
ΔE = -13.6 eV + 0.6 eV = -13.0 eV
Converting the energy difference to joules:
ΔE = -13.0 eV * 1.6 x 10⁻¹⁹ J/eV = -2.08 x 10⁻¹⁸ J
Substituting the values into the relative density equation:
Relative Density = exp(-(-2.08 x 10⁻¹⁸ J) / (1.38 x 10⁻²³ J/K * 300 K))
Relative Density ≈ 0.73
Therefore, for the transition between n=1 and n=6, the relative density is approximately 0.73.
b) For the transition between n=25 and n=26, the energy difference is:
ΔE = E₁ - E₂ = (-13.6 eV / 25²) - (-13.6 eV / 26²)
ΔE ≈ -13.6 eV + 0.0585 eV ≈ -13.5415 eV
Converting the energy difference to joules:
ΔE ≈ -13.5415 eV * 1.6 x 10⁻¹⁹ J/eV ≈ -2.1664 x 10⁻¹⁸ J
Substituting the values into the relative density equation:
Relative Density = exp(-(-2.1664 x 10⁻¹⁸ J) / (1.38 x 10⁻²³ J/K * 300 K))
Relative Density ≈ 0.995
Therefore, for the transition between n=25 and n=26, the relative density is approximately 0.995.
Q4. Derivation of the Lambert-Beers law:
To derive the Lambert-Beers law, we consider a thin slice of the absorber with thickness dx. The intensity of light passing through this slice decreases due to absorption.
The change in intensity, dI, within the slice can be expressed as the product of the intensity at that position, I(x), and the fraction of light absorbed within the slice, nσ(λ)dx:
dI = -I(x) * nσ(λ)dx
The negative sign indicates the decrease in intensity due to absorption.
Integrating this equation from x = 0 to x = x (the total thickness of the absorber), we have:
∫[0,x] dI = -∫[0,x] I(x) * nσ(λ)dx
The left-hand side represents the total change in intensity, which is equal to I₀ - I(x) since the initial intensity is I₀.
∫[0,x] dI = I₀ - I(x)
Substituting this into the equation:
I₀ - I(x) = -∫[0,x] I(x) * nσ(λ)dx
Rearranging the equation:
I(x) = I₀ * exp(-nσ(λ)x)
This is the Lambert-Beers law, which shows the exponential decrease in intensity (photon flux) as light passes through an absorber. The law quantifies the dependence of intensity on the density of the absorber, the absorption cross section, and the position within the absorber.
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if 18.2 ml of 0.800 m hcl solution are needed to neutralize 5.00 ml of a household ammonia solution, what is the molar concentration of the ammonia?
The molar concentration of ammonia is 2.976M.
Molarity of HCl = number of moles/ volume
Number of moles = Molarity of Hcl * volume
Hence the number of moles of ammonia =\(14.88 * 10^{-3}\)
From question volume of ammonia =\(5 * 10^{-3}\)
Molarity = \(14.88 * 10^{-3}/5 * 10^{-3}\)
Molarity \(=2.976\)
What is meant by molar concentration?
Molar concentration is the most effective way of describing a solute concentration in a solution. Molarity is described as the total number of moles of solute dissolved per liter of solution,i.e., M = mol/L.
How do you calculate the molar concentration?
To calculate the Molar Concentration, we will find the molar concentration by dividing the moles by the liters of water used in the solution.
Thus, the molar concentration of ammonia is 2.976M
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If Sara was planning a wedding and wanted to have a sculpture of a heart made of
butter at the reception, describe how Sara could test the temperature range at
which the heart would remain a solid.
Answer:
check the Ac so ya so ya so ya so ya so ya so ya
Answer:
Butter stored in a refrigerator is a solid. Sara should put a thermometer in the refrigerator for an hour and record this temperature.
In a chemical reaction, 247 g of copper carbonate was heated and 149.2 g of copper oxide was made.
a. RFM CuCO₃ = 123.5
RFM CuO = 79.5
b. 159 g
c. 93.84%
Further explanationGiven
247 g of copper carbonate
149.2 g of copper oxide
Required
a. RFM(relative formula mass)
b. the mass of CuO
c. % yield
Solution
Reaction
CuCO₃⇒CuO+CO₂
a.
RFM CuCO₃ = 63.5+12+3.16=123.5
RFM CuO = 63.5 + 16 = 79.5
b. mol CuCO₃ :
mol = mass : MW
mol = 247 : 123.5
mol = 2
From equation, mol ratio CuCO₃ : CuO = 1 :1 , so mol CuO = 2
mass CuO = 2 x 79.5 = 159 g
c. % yield = (actual/theoretical) x 100%
\(\tt %yield=\dfrac{149.2}{159}\times 100\%=93.8\%\)%yield = (149.2/159) x 100% = 93.84%
what is disproportionation reaction and give one example of it ?
Answer:
A disproportionation reaction is when a multiatomic species whose pertinent element has a specific oxidation state gets oxidized and reduced in two separate half-reactions, yielding two other products containing the same pertinent element. A convenient example is Mn2O3 becoming Mn2+ and MnO2 .
please help quickly
Rubia was given a type of inclined plane called a ramp in her science class. Her teacher told her that the ramp should have a mechanical advantage of 3.
Rubia pulled a block up the ramp, but afterward she calculated that the mechanical advantage of the ramp was 2.8 instead of 3. Her teacher said she did not make a mistake. What did Rubia calculate?
A.
the actual operating power of the ramp
B.
the actual mechanical advantage of the ramp
C.
the ideal mechanical advantage of the ramp
D.
the ideal operating power of the ramp
Answer: B. The actual mechanical advantage of the ramp.
Explanation:
The professor saying that the ramp SHOULD have a mechanical advantage of 3 indicates that that would be the ideal mechanical advantage. Since Rubia calculated it to be 2.8, that means that it is the acutal mechanical advantage. The actual advantage will be reduced from the ieal due to things like friction.
Enthalpy
Explain how the heat measured in Example 5.5 differs from the enthalpy change for the exothermic reaction described by the following equation:
HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)
Reference Example 5.5
Heat Produced by an Exothermic Reaction
When 50.0 mL of 0.10 M HCl(aq) and 50.0 mL of 0.10 M NaOH(aq), both at 22.0 °C, are added to a coffee cup calorimeter, the temperature of the mixture reaches a maximum of 28.9 °C. What is the approximate amount of heat produced by this reaction?
HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)
The equation q = -H, where q is the heat emitted or absorbed and H is the enthalpy change, relates the heat measured in Example 5.5 to the reaction's enthalpy change.
What kind of reaction happens when NaOH and HCl are combined?An acid and base interaction of this kind is referred to as a neutralization reaction. In the equation above, the base NaOH reacts with the acid HCl to generate the salt NaCl.
Will HCl raise the temperature?Therefore, since this creation is so powerful and produces a tremendous amount of energy, when the hydrochloric acid is dissolved in water, the hydrogen ions will form hydrogen bonding with the oxygen atom of the water molecule.
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KOH + _co2 -_ксоз + _Н,0
Answer:
2KOH + 3co2 ------->2ксоз + 2Н20
Tori created the following table to summarize the key features of the three types of magma. What correction needs to be made?
The correction that is needed to be made is Rhyolitic and Andesitic should be switched Basaltic and Andesitic should be switched'. The correct option is D.
What is magma?Magma is a molten or semi-molten substance that is found under the earth. It forms igneous rocks. It is very hot, liquid, and semi-liquid. When it came above the earth, it is called lava.
The basaltic is high viscosity lava, whereas the andesitic is low viscosity lava. Andesitic has low reactivity and explosivity. Basaltic lava has reactivity and explosivity.
Thus, the correct option is D.
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The question is incomplete. Your most probably complete question is given below:
Gas Content Low Intermediate High Explosivity Low Intermediate High.
Gas Content should be reversed ("High" under Basaltic and Low' under Andesitic).
Explosivity should be reversed 'High under Basaltic and Low under Andesitic).
Rhyolitic and Andesitic should be switched Basaltic and Andesitic should be switched'
What most likely occurred during this demonstration?
In a science demonstration, a teacher mixed zinc (Zn)
with hydrogen chloride (HCI) in a flask and quickly
attached a balloon over the mouth of the flask Bubbles
formed in the solution and the balloon inflated,
O The Zn and HCl both retained their identity
Either Zn or HCI, but not both, retained its identity
O Evaporation of one of the substances occurred
One or more new substances formed
Answer:
Hydrogen gas and a salt formed at the end of the reaction.
Explanation:
Hydrogen Gas has formed which inflated the balloon
Usually, metals and acids react to form a salt and Hydrogen Gas.
Here's what happened:
Zn (s) + 2HCl (aq) → \(ZnCl_2\)(aq) +\(H_2\)(g)
Cheers :)
Answer:
One or more new substances formed.
Explanation:
This is an example of a chemical property because bubbles formed, and the mixture produced a gas which allowed the balloon to inflate. The production of bubbles is an indicator of a chemical change. When a chemical change occurs, one or more new substances form as a result.
- I took the quiz and got 100%
Hope this helps!
g how many minutes will be required to deposit 1.00 g of chromium metal from an aqueous croisolution using a current of 6.00 a?
The time that is required to deposit 1.00 g of chromium metal is 30.9 mins.
Faraday's II Law of electrolysis states that if the equal quantity of energy is handed thru extraordinary electrolytes, the loads of ions deposited on the electrodes are without delay proportional to their chemical equivalents.
The chemical equation of the reaction can be represented as follows:
Cr6+ + 6e → Cr
Moles of Cr = mass / molar mass = 1 / 52 = 0.0192 mol
Moles of electrons needed = 6 * moles of Cr = 6 * 0.0192 = 0.1152 mol
Charge needed = moles of e * charge per mole of e = 0.1152 * 96485.33 = 11115.110 C
Now time needed = charge / current = 11115.110 / 6 = 1852.52 seconds = 1852.52 / 60 min = 30.9 min
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from the following list of elements, select those that will always form ionic compounds in a 1:1 ratio with alkaline earth metals.
a. Sulfur
b. Silver
c. Magnesium
d. Chlorine
e. Phosphorous
f. Nitrogen
g. Cadmium
h. Aluminum
i. cesium
Which carbon is bound to an oh group in deoxyribose?.
Answer:
In DNA nucleotides, the 3′ carbon of the sugar deoxyribose is attached to a hydroxyl (OH) group.
Briefly answer the following questions, including reasoning and calculations where appropriate: (a) Explain in your own words why direct expansion systems require the vapour exiting the evaporator to be superheated. (8 Marks) (b) Describe the difference between a forced draft evaporator and an induced draft evaporator, and describe why (and in what type of system) a forced draft evaporator is often preferred over an induced draft evaporator. (6 Marks) (c) Determine the R-number of each of the following refrigerants, and hence classify them (ie chlorofluorocarbon, hydrocarbon etc): (i) CClF 2
CF 3
(3 Marks) (ii) Tetrafluoroethane (3 Marks) (iii) H 2
O (3 Marks) (d) Briefly describe the role of hydrogen gas in an absorption refrigeration system (NH 3
/H 2
O/H 2
). In a system where the evaporating temperature is −2.0 ∘
C, with a design condensing temperature of 38.0 ∘
C, estimate the partial pressure of hydrogen in the evaporator.
Direct expansion systems require the vapour exiting the evaporator to be superheated to avoid liquid slugging, to improve the effectiveness of the evaporator and to maintain the stability of the compressor. (B) Forced draft and induced draft evaporators differ in the way air is introduced into them. (C) CClF2CF3 (also known as R12) is a chlorofluorocarbon refrigerant. (ii) Tetrafluoroethane (also known as R134a) is a hydrofluorocarbon refrigerant and H2O is not classified as a refrigerant. (D) The partial pressure of hydrogen in the evaporator is 1.6 mmHg.
(a) Direct expansion systems are those in which the refrigerant in the evaporator evaporates directly into the space to be cooled or frozen. The evaporator superheat is used to make sure that only vapor and no liquid is carried over into the suction line and compressor. Superheating is required for the following reasons :
To avoid liquid slugging : Liquid slugging in the compressor's suction line can be caused by a lack of superheat, which can result in compressor damage. To improve the effectiveness of the evaporator : Superheating increases the evaporator's efficiency by allowing it to absorb more heat. To maintain the stability of the compressor : The compressor is protected from liquid by the correct use of superheat, which ensures that only vapor is returned to the compressor.(b) Forced draft and induced draft evaporators differ in the way air is introduced into them. In an induced draft evaporator, a fan or blower is positioned at the top of the evaporator, and air is drawn through the evaporator from the top. In a forced draft evaporator, air is propelled through the evaporator by a fan or blower that is located at the bottom of the evaporator. Forced draft evaporators are frequently used in direct expansion systems because they allow for better control of the air temperature. Because the air is directed upward through the evaporator and out of the top, an induced draft evaporator is less effective at keeping the air at a uniform temperature throughout the evaporator.
(c) (i) CClF2CF3 (also known as R12) is a chlorofluorocarbon refrigerant.
(ii) Tetrafluoroethane (also known as R134a) is a hydrofluorocarbon refrigerant.
(iii) H2O is not classified as a refrigerant.
(d) The function of hydrogen gas in an absorption refrigeration system (NH3/H2O/H2) is to increase the heat of reaction between ammonia and water.
The pressure of hydrogen gas in the evaporator of an absorption refrigeration system can be determined using the formula, Pa/Pb = (Ta/Tb)^(deltaS/R),
where Pa = partial pressure of hydrogen in the evaporator, Ta = evaporating temperature, Tb = condensing temperature, Pb = partial pressure of hydrogen in the absorber, deltaS = entropy change between the absorber and evaporator, R = gas constant.
Substituting the given values, Ta = −2.0 ∘C = 271 K ; Tb = 38.0 ∘C = 311 K ; Pb = atmospheric pressure = 1 atm ;
deltaS = 4.7 kJ/kg K ; R = 8.314 kJ/mol K
we get, Pa/1 atm = (271/311)^(4.7/8.314)
Pa = 0.021 atm or 1.6 mmHg
Therefore, the partial pressure of hydrogen in the evaporator is 1.6 mmHg.
Thus, Direct expansion systems require the vapour exiting the evaporator to be superheated to avoid liquid slugging, o improve the effectiveness of the evaporator and to maintain the stability of the compressor. (B) Forced draft and induced draft evaporators differ in the way air is introduced into them. (C) CClF2CF3 (also known as R12) is a chlorofluorocarbon refrigerant. (ii) Tetrafluoroethane (also known as R134a) is a hydrofluorocarbon refrigerant and H2O is not classified as a refrigerant. (D) The partial pressure of hydrogen in the evaporator is 1.6 mmHg.
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When molybdate (MoO3) and Zinc (Zn) are heated together they react in this equation:
3Zn + 2MoO3 → Mo2O3 + ZnO
What is the mole ratio of Zn to Zno?
Answer: The mole ratio of Zn to ZnO is 3: 3.
Explanation:
According to law of conservation of mass, mass can be neither be created nor be destroyed. The mass on reactant side must be equal to the mass on product side. Thus the atoms of each element on both side of the reaction must be same.
The balanced chemical reaction is:
\(3Zn+2MoO_3\rightarrow Mo_2O_3+3ZnO\)
Here 3 moles of Zn combine with 2 moles of \(MoO_3\) to give 1 mole of \(Mo_2O_3\) and 3 moles of \(ZnO\). Thus the mole ratio of Zn to ZnO is 3: 3.
What is indicated by 'a' in the figure below
The A in the diagram indicates +VE. The correct option is D.
What is enthalpy?Enthalpy is the result of the pressure, volume, and internal energy of the system added together.
The diagram demonstrates that, as indicated in the previous response, Hrxn is positive since the enthalpy of the products is higher than the enthalpy of the reactants.
The enthalpy of a reaction is determined by comparing the total enthalpy (heat content) of the reaction's products to the total enthalpy (heat content) of its reactants.
Thus, the correct option is D. +VE.
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Newton's Third Law of Motion states that objects exert equal forces on each other in opposite directions.
Which of the following examples best describe Newton's Third Law of Motion?
O
A. waiter pulls off the tablecloth but the dishes remain
O
B. a ball rolling down and incline plane
C. a baseball bat resting against a wall
D. truck crashes into a car
Answer:
Truck crashes into a car
The rocksalt structure, the FCC metal structure and the BCC metal structure all have close packed directions. List the FAMILY of close packed directions for each structure.
Rocksalt Structure: No close-packed directions.
FCC Metal Structure: [111] family of close-packed directions.
BCC Metal Structure: [110] family of close-packed directions.
The rock salt structure has a face-centered cubic (FCC) arrangement of both cations and anions. In this structure, there are no close-packed directions because the ions are arranged in a simple cubic pattern. Consider the [100], [010], and [001] directions as the primary directions of the rock salt structure.
In an FCC metal structure, the close-packed directions are represented by the [111] family. The [111] direction is the densest and corresponds to the stacking of atoms along the body diagonal of the cube. The [111] family includes directions such as [111], [1-11], [11-1], [1-1-1], [-111], [-1-11], [-11-1], and [-1-1-1].
In a BCC metal structure, the close-packed directions are represented by the [110] family. The [110] direction is the densest and corresponds to the stacking of atoms along the cube edge diagonal. The [110] family includes directions such as [110], [1-10], [-110], and [-1-10].
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.
Which of the following describes Pluto?
1. asteroid
2. moon
3. planet
4. dwarf planet
Answer:
4. dwarf planet
Explanation:
24. what is the most likely method of decay of the radioactive isotope technicium-99 (99tc)? a. alpha decay b. beta decay c. electron capture d. positron emission e. both electron capture and positron emission
The radioactive isotope Technium-99 decays most likely through alpha decay (99tc). An atomic nucleus emits an alpha particle during the radioactive decay process known as "alpha decay".
and then changes or "decays" into a separate atomic nucleus with a mass number that is decreased by four and an atomic number that is decreased by two. The nucleus of an atom of helium-4 is the same as an alpha particle. Radioisotopes are an element's radioactive isotopes. They are the atoms with unstable neutron-proton combinations or excess energy in their nuclei. During those processes, the radionuclide is said to experience radioactive decay, albeit the surplus energy may be put to use in any number of ways.
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HELP PLS
I NEED THE BOTTOM TO BE a matched up by the top PLS ASSAPPp
Answer:
a: milliliters and grams | b: heat | c: force | d: solid | e: attraction
Explanation:
A: milliliters are cubic and grams are weight.
b: heat make particles go faster
c: thus more collisions and temperature and force
d: solid, they can't move, just vibrate
e: attraction
explain why almunium is often used for long distance over head electric cables (high voltage)
Answer:
because it does not cost much and can be found easily. due to their low resistance and excellent conductivity.
Explanation:
Use the table below to answer the
following question.
Energy released by fusion of hydrogen in 1 liter of solution A [8.4 x 10^12]
Electrical energy used daily in a certain family home [3 x 10^8]
Question:
If you could generate energy by fusing the
hydrogen in solution A, how much of the
solution would you need to generate the
electrical energy used daily by a certain home?
Answer in liter(s)
(Use scientific notation. Use the multiplication symbol in the math palette as needed. Round to one decimal place as
needed.)
To determine how much of solution A would be needed to generate the electrical energy used daily in the home
we need to calculate the ratio of the energy released by fusion of hydrogen to the electrical energy used daily.
Energy ratio = Energy released by fusion of hydrogen / Electrical energy used daily
Energy ratio = (8.4 x 10^12) / (3 x 10^8)
To simplify the calculation, we can convert the values to scientific notation with the same exponent:
Energy ratio = (8.4 / 3) x (10^12 / 10^8)
Energy ratio = 2.8 x 10^4
This means that for every unit of electrical energy used daily in the home, we would need 2.8 x 10^4 units of solution A to generate that energy.
Therefore, to generate the electrical energy used daily in the home, we would need 2.8 x 10^4 liters of solution A.
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which solution contains 0.2 mol of potassium hydroxide, koh? group of answer choices 1 cm^3 of 0.2 mol dm^-3 koh(aq) 10 cm^3 of 0.2 mol dm^-3 koh(aq) 100 cm^3 of 2.0 mol dm^-3 koh(aq) 1 dm^3 of 2.0 mol dm^-3 koh(aq)
The answer is 10 cm^3 of 0.2 mol dm^-3 KOH(aq). This is because the molarity of the solution is 0.2 mol/dm^3, and 0.2 mol of KOH can be found in 10 cm^3 of the solution.
The molar concentration of a solution can be used to determine the amount of solute in a given volume of solution. This is done by multiplying the molar concentration by the volume of solution. For example, if you wanted to know how many moles of KOH were in 10 cm^3 of 0.2 mol/dm^3 solution, you would multiply 0.2 by 0.001 (10 cm^3 is equal to 0.001 liters), giving you 0.2 moles of KOH.
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(c) The student finds that 21.50 cm³ of hydrochloric acid is needed to neutralise 25.0 cm³ of sodiu
hydroxide solution.
(i) Describe what the student should do next to prepare a pure solution of sodium chloride.
Answer:
After neutralizing the sodium hydroxide solution with hydrochloric acid, the student should remove any excess hydrochloric acid and water from the solution to obtain a pure solution of sodium chloride. This can be done by a process called evaporation or by using a separating funnel.
To prepare a pure solution of sodium chloride, the student should follow the steps below:
Transfer the neutralized solution of sodium chloride into an evaporating dish.
Heat the evaporating dish over a low flame, stirring continuously until all the water evaporates.
Once all the water has evaporated, the student will be left with a dry residue of sodium chloride in the evaporating dish.
The sodium chloride can then be transferred to a clean, dry container and stored for use.
Alternatively, the student can use a separating funnel to remove excess hydrochloric acid and water from the solution. In this case, the neutralized solution is transferred to a separating funnel, and an equal volume of water is added. The funnel is then shaken, and the two layers are allowed to separate. The bottom layer containing the excess hydrochloric acid is drained off, leaving behind a pure solution of sodium chloride.
Explanation:
Where does the 'Equiv' come from?
Explanation:
Equiv means equivalent ...
How do weak intermolecular bond strengths affect the melting and boiling point of a substance?
The melting point is lower, but the boiling point is higher.
Both the melting point and boiling point are lower.
The melting point is higher, but the boiling point is lower.
Both the melting point and boiling point are higher.
Considering the definition of intermolecular bond, the correct answer is second option: Both the melting point and boiling point are lower.
The molecules of covalent compounds can be held together through electrostatic interactions known as "intermolecular forces", which are characterized by holding more than one molecule together. Therefore, they are related to chemical bonds, which have the goal of making molecules stick together or separate.
In other words, intermolecular forces or bonds are those interactions that hold molecules together. These are electrostatic forces.
The presence of these forces explains, for example, the properties of solids and liquids.
They differ from intramolecular forces, because of these, they correspond to interactions that hold the atoms in a molecule together. In general, intermolecular forces are much weaker than intramolecular forces.
On the other side, the melting point is the temperature at which a substance goes from solid to liquid at a given pressure. Similarly, the boiling point is the temperature at which the substance passes from a liquid to a gaseous state.
Finally, the more intense the intermolecular forces, the higher the melting point and the boiling point of a substance because these are the forces that must be overcome to separate them.
In summary, the correct answer is second option: Both the melting point and boiling point are lower.
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https://brainly.com/question/4889416?referrer=searchResultshttps://brainly.com/question/25729379?referrer=searchResultsa sample of neon is at 89c and 123 kpa. if the pressure changes to 145 kpa and the volume remains constant, what is the new temperature, in c?
The new temperature of the neon gas is 151.45°C when the pressure changes to 145 kPa and the volume remains constant.
Assuming that the amount of neon gas remains constant, we can use the combined gas law to find the new temperature. The combined gas law states that:
(P1 x V1) / T1 = (P2 x V2) / T2
where P1, V1, and T1 are the initial pressure, volume, and temperature, respectively, and P2, V2, and T2 are the final pressure, volume, and temperature, respectively. We are given P1 = 123 kPa, T1 = 89°C = 362 K, V1 = V2 (since the volume remains constant), and P2 = 145 kPa. Substituting these values into the combined gas law equation gives:
(123 kPa x V) / 362 K = (145 kPa x V) / T2
Simplifying this equation by cross-multiplying and rearranging gives:
T2 = (145 kPa x 362 K) / 123 kPa
T2 = 424.6 K
Finally, we can convert the temperature from Kelvin to Celsius by subtracting 273.15:
T2 = 424.6 K - 273.15
T2 = 151.45°C
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There are ________ mol of carbon atoms in 4 mol of C4H8O2
There are 16 mol of carbon atoms in 4 mol of C4H8O2
The chemical formula C4H8O2 tells us that each molecule of this compound contains 4 carbon atoms, 8 hydrogen atoms, and 2 oxygen atoms. Therefore, to determine the number of carbon atoms in 4 mol of C4H8O2, we need to multiply the number of moles by the number of carbon atoms per molecule:
Number of carbon atoms = number of moles × number of carbon atoms per molecule
Number of carbon atoms = 4 mol × 4 carbon atoms per molecule
Number of carbon atoms = 16 mol
So there are 16 mol of carbon atoms in 4 mol of C4H8O2. It's important to note that the chemical formula of a compound gives us information about the ratio of atoms in the compound, which allows us to determine the number of atoms in a given amount of the compound.
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What is the mass of 0.20 mole of glucose C6H12O6?
a. 230 g
b. 36 g
c. 23 g
d. 4.6 g
Answer:
answer will be b
Explanation:
mole is given 0.20
you have to find mass so just convert it into mass
remember if you move away from mole you multiply and if you move towards mole you divide so
just multiply mole with molar mass of glucose
so
0.20×180 = 36 grams
simple keep learning.......