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When Americium (Am-241) undergoes alpha decay(He-4) it forms neptunium (Np-237) based on the following pathway:
²⁴¹Am₉₅ → ²³⁷Np₉₃ + ⁴He₂
The energy released in given as:
ΔE = Δmc²
where Δm = mass of products - mass of reactants
= [m(Np-237) + m(He-4)] - [m(Am-241)]
= 237.0482+4.0015-241.0568 = -0.0073 g/mol = -7.3 * 10⁻⁶ kg/mol
ΔE = -7.3*10⁻⁶ kg/mol * (3*10⁸ m/s)² = -5.84*10¹¹ J/mol
Related Questions
The standard free energy change for a reaction can be calculated using the equation ΔG∘′=−nFΔE∘′ ΔG∘′=−nFΔE∘′ where nn is the number of electrons transferred, FF is Faraday's constant, 96.5 kJ·mol−1·V−1, and ΔE∘′ΔE∘′ is the difference in reduction potential. For each of the given reactions, determine the number of electrons transferred (n)(n) and calculate standard free energy (ΔG∘′)(ΔG∘′) . Consider the half-reactions and overall reaction for reaction 1. half-reactions:fumarate 2−+2H+CoQH2↽−−⇀succinate−↽−−⇀CoQ+2H+ half-reactions:fumarate−+2H+↽−−⇀succinate2−CoQH2↽−−⇀CoQ+2H+ overall reaction:fumarate2−+CoQH2↽−−⇀succinate2−+CoQΔE∘′=−0.009 V
A mass of 34.05 g of H2O(s) at 273 K is dropped into 185 g of H2O(l) at 310. K in an insulated container at 1 bar of pressure. Calculate the temperature of the system once equi- librium has been reached. Assume that CP, m for H2O is con- stant at its values for 298 K throughout the temperature range of interest.
You have 2.2 mol Xe and 2.0 mol F2, but when you carry out thereaction you end up with only 0.25 mol XeF4. What is the percent yieldof this experiment?Xe(g) + 2 F2 (g) - XeF. (g)
how does the volume of an ideal gas at constant temperature and pressure change as the number of moleculess increeases
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Answer and Explanation:
(a) Na and H : The compound formed by Na and H is sodium hydride which formula is NaH
(b) B and O : The compound formed by Ba and O is barium oxide which formula is BaO
(C)Na and S : The compound formed by Na and S is sodium sulfide which formula is
(D) Al and F : The compound formed by Al and F is aluminium fluoride which formula is
(E) F and O : The compound formed by F and O is oxygen fluoride which formula is
(F) Sr and Cl : The compound formed by Sr and Cl is strontium chloride which formula is
Answers
The vapor pressure of the solution would be as follows:
torr
Given that,
Vapor pressure of Carbon Disulfide torr
Naphthalene's mass
Naphthalene's molar mass
Now,
We know that
Number of moles
Mass ×
×
So,
Number of moles of Carbon Disulfide ×
moles of Carbon Disulfide
Number of moles of Naphthalene:
Number of moles
Now,
Total number of moles :
moles
Mole fraction of each compound in solution :
Carbon Disulfide:
2.567 / 2.65
Naphthalene
0.083 / 2.65
According to Raoult's:
P ×
Carbon Sulfide = Solvent
Mole fraction of solvent
Vapour pressure of the pure solvent
×
torr
Thus, " torr" is the correct answer.
Learn more about "Pressure" here:
Answer:
344.5764 torr
Explanation:
Molar mass of naphthalene = 128.2g/mol
Mass of naphthalene = 10.60 g
Carbon disulfide:
Molar mass= 76.14g/mol ;
volume = 155mL ;
density = 1.261 g/mL
Vapour pressure = 355.6 torr
Number of moles = mass / molar mass
CS2:
Mass = density × volume
Number of moles = (density × volume) / molar mass
Number of moles = (1.261 * 155) / 76.14 = (195.455 / 76.14) = 2.567 moles of CS2
Number of moles of C8H10:
Number of moles = 10.60 / 128.2 = 0.083 C8H10
Total number of moles :
2.567 + 0.083 = 2.65 moles
Mole fraction of each compound in solution :
CS2 :
2.567 / 2.65 = 0.969
C8H10:
0.083 / 2.65 = 0.031
According to Raoult's:
Psolution = Xsolvent × Posolvent
CS2 = solvent
Xsolvent = Mole fraction of solvent
Posolvent = Vapour pressure of pure solvent
Psolution = 0.969 × 355.6 torr = 344.5764 torr
b. An endothermic reaction that only proceeds when coupled to an exothermic reaction
c. An endothermic reaction that only proceeds when a catalytst is present
d. An endothermic reaction which is not spontaneous
e. All of the above
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Answer: Option (c) is the correct answer.
Explanation:
It is given that the scientist is claiming that all the spontaneous reactions are exothermic in nature.
And, it is known that when a reaction is spontaneous in nature then is negative.
Now, the relation between Gibb's free energy, enthalpy and entropy is as follows.
=
So, when a catalyst is present in a chemical reaction then we do not need to give large amount of heat from outside. And, because of this the enthalpy of reaction will not be highly positive.
Hence, the value of will result in a negative value which means the reaction is spontaneous.
Thus, we can conclude that an endothermic reaction that only proceeds when a catalytst is present, would provide the strongest challenge to their claim.
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Answer:
Based on the difference in solubility one can perform the process of purification of the benzoic acid contaminated with sodium chloride. The benzoic acid does not get soluble in cold water, while the sodium chloride is soluble in cold water.
Thus, for separation, the supplementation of cold water can be done into the mixture in the experiment of purifying benzoic acid from sodium chloride. In the process, the mixture is placed on the ice bath and is stirred well, in the end, the solution is filtered. The filtrate contains sodium chloride and on the filter paper pure benzoic acid is collected.
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Answer:
The human cheek cell is a good example of a typical animal cell. It has a prominent nucleus and a flexible cell membrane which gives the cell its irregular, soft-looking shape.