Answer:
D. The mixing of warm and cold water
Explanation:
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.
Answer:
The ΔHrxn for the above equation = 179 kJ/mol
Explanation:
The reaction bond enthalpies are for the reactant;
3 × N-H = 3 × 390 = 1,170 kJ/mol
2 × O=O = 2 × 502 = 1004 kJ/mol
The reaction bond enthalpies are for the product;
3 × N-O = 3 × 201 = 603 kJ/mol
3 × O-H = 3 × 464 = 1,392 kJ/mol
The ΔHrxn for the above equation is therefore;
ΔHrxn = 1,170 + 1,004 - (603 + 1,392) = 179 kJ/mol
1,140,480 inches
Explanation:
Multiply 63,360 inches by the amount of miles you want.
This case:
63,360 inches x 18 miles = 1,140,480 inches
The total pressure = 1.402 atm
<u><em>calculation</em></u>
Total pressure = partial pressure of gas A + partial pressure of gas B + partial pressure of third gas
partial pressure of gas A= 0.205 atm
Partial pressure of gas B =0.658 atm
partial pressure for third gas is calculated using ideal gas equation
that is PV=nRT where,
p(pressure)=? atm
V(volume) = 8.65 L
n(moles)= 0.200 moles
R(gas constant)=0.0821 L.atm/mol.k
T(temperature) = 11°c into kelvin =11+273 =284 k
make p the subject of the formula by diving both side by V
p =nRT/v
p = [(0.200 moles x 0.0821 L.atm/mol.K x 284 K)/8.65L)] =0.539 atm
Total pressure is therefore = 0.205 atm +0.658 atm +0.539 atm
=1.402 atm
