Explanation:
Knowing the pH, you know the concentration of protons:
−log[H+]=pH=3.7
[H+]=10−3.7 M
Now, since the weak (monoprotic) acid dissociates into its conjugate base and a proton, the mols of protons are equimolar with the mols of conjugate base---the protons came FROM the weak acid, so the conjugate base that forms must be equimolar with the protons given out to the solvent.
HA⇌A−+H+
Hence, [A−]=[H+] in the same solution volume. Using the equilibrium constant expression, we get:
Ka=[H+]2eq[HA]eq
Don't forget that the HA form of HA had given away protons, so the mols of protons given away to generate A− is subtracted from the mols of (protons in) HA.
=[H+]2eq[HA]i−[H+]eq
=(10−3.7M)20.02M−10−3.7M
Ka=2.0105×10−6 M
The energy of a photon : 7.645 x 10⁻³⁴ J
<h3>Further explanation
</h3>
Radiation energy is absorbed by photons
The energy in one photon can be formulated as
Where
h = Planck's constant (6,626.10⁻³⁴ Js)
f = Frequency of electromagnetic waves
f = c / λ
, Hz
c = speed of light
= 3.10⁸ m/s
λ = wavelength
,m
wavelength λ of 2.60 ✕ 10⁻⁸ m
The energy :
Nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts (lighter nuclei). The fission process often produces free neutrons and photons (in the form of gamma rays), and releases a large amount of energy. In nuclear physics, nuclear fission is either a nuclear reaction or a radioactive decay process. The case of decay process is called spontaneous fission and it is very rare process. In this section, the neutron-induced nuclear fission, the process of the greatest practical importance in reactor physics, will be discussed.
Fusion reactions between light elements, like fission reactions that split heavy elements, release energy because of a key feature of nuclear matter called the binding energy, which can be released through fusion or fission. The binding energy of the nucleus is a measure of the efficiency with which its constituent nucleons are bound together. Take, for example, an element with Z protons and N neutrons in its nucleus. The element’s atomic weight A is Z + N, and its atomic number is Z. The binding energy B is the energy associated with the mass difference between the Z protons and N neutrons considered separately and the nucleons bound together (Z + N) in a nucleus of mass M. The formula is
B = (Zmp + Nmn − M)c2.
Answer:
ΔS = 16.569 J/K
Explanation:
In this case, we need to use the correct expression to solve this. In thermodynamics, the expression to use that puts a relation between heat, temperature and entropy is the following:
ΔS = Q/T
To determine the entropy change of the universe, we need to sum the entropy change of Earth and the entropy of the sun.
As the sun is transfering radiation to Earth, the sun is losing energy, therefore, heat is negative, while Earth receives the heat, so it's positive. Calculating the entropy for the sun and Earth:
ΔSs = -Q/Ts
ΔSe = Q/Te
ΔSu = ΔSe + ΔSs
Let's calculate both entropies by separate:
ΔSe = 5x10^3 / 285 = 17.54 J/K
ΔSs = -5x10^3 / 5,150 = -0.971 J/K
Therefore, the entropy of universe:
ΔSu = 17.54 - 0.971
ΔSu = 16.569 J/K
Answer:
92.65256 cm^3
Explanation:
To find this, we can simply multiply all three dimensions to get the answer in cubic centimeters, and we get the answer above. If you want to be more specific, we can go by the sigfig rule and the answer would be rounded to 93 cm^3.
