Answer:
c. 298 K
Explanation:
Nernst equation is an equation used in electrochemistry that relates the reduction potential of a reaction with the standard potential, temperature and concentrations of the reactants in that are been reducted and oxidized. The formula is:
E = E° - RT / nF ln [Red] / [Ox]
<em>Where R is gas constant (8.314J/molK), T is absolute temperature (In Kelvin), n are moles of electrons and F is faraday constant (K/Volt*mol)</em>
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In electrochemistry, standard temperature is taken as 298K. That means by assuming standard temperature we can substitute T as:
<h3>c. 298 K</h3>
Answer:
10 moles of SO₂ are produced when 5 moles of FeS₂
Explanation:
Stoichiometry: it is the theoretical proportion in which the chemical species are combined in a chemical reaction. The stoichiometric equation of a chemical reaction relates molecules or number of moles of all the reagents and products that participate in the reaction.
In other words, stoichiometry establishes relationships between the molecules or elements that make up the reactants of a chemical equation with the products of said reaction. The relationships established are molar relationships (that is, moles) between the compounds or elements that make up the chemical equation.
The stoichiometric coefficients of a chemical reaction indicate the proportion in which said substances react.
Taking into account the above, you can apply the following rule of three: by stoichiometry if 4 moles of FeS₂ produce 8 moles of SO₂, then when reacting 5 moles of FeS₂ how many moles of SO₂ will they produce?
moles of SO₂= 10
<u><em>10 moles of SO₂ are produced when 5 moles of FeS₂</em></u>
Answer:
A = 0.75 ×10² KJ.
B = 3.9 ×10³ dg
C = 0.22 × 10² μl.
Explanation:
A = 7.5 ×10⁴ j to kilo joules
7.5 ×10⁴ / 1000 = 0.75 ×10² KJ.
Joule is the smaller unit while kilo joule is the larger unit. One kilo joule equals to the thousand joule that's why we will divide the given value by 1000 in order to convert into KJ.
B = 3.9 ×10⁵ mg to decigrams.
3.9 ×10⁵ / 100 = 3.9 ×10³ dg
Decigram is larger unit while milligram is smaller unit. One decigram is equal to the 100 milligram. In order to convert the given value into decigram we have to divide the value by 100.
C = 2.21 ×10⁻⁴ dL to micorliters
2.21 ×10⁻⁴ ×10⁵ = 0.22 × 10² μl.
Deciliter is bigger unit then micro liter . One deciliter equals to the 100000 micro liters. In order to convert the dL into micro liter we have to multiply the given value with 100000.
To calculate how many photons are in a certain amount of energy (joules) we need to know how much energy is in one photon.
Start by using two equations:
Energy of a photon = Frequency * Planck's constant (6.626 * 10^(-34) J-s)
Speed of light (constant 3 * 10^8 m/s) = Frequency * Wavelength
Which means:
frequency = Speed of Light / Wavelength
So energy of a photon = (Speed of light * Planck's constant)/(Wavelength)
You may have seen this equation as E = hc/<span>λ</span>
We have a wavelength of 691 nm or 691 * 10^-9 meters
So we can plug in all of our knowns:
E = (6.626 * 10^(-34) J-s) * (3.00 * 10^8 m/s) / (691 * 10^-9 m) =
2.88 * 10^(-19) joules per photon
Now we have joules per photon, and the total number of joules (0.862 joules)
,so divide joules by joules per photon, and we have the number of photons:
0.862 J/ (2.88 * 10^(-19) J/photon) = 3.00 * 10^18 photons.
