<span>E=hν</span> where E is the energy of a single photon, and ν is the frequency of a single photon. We recall that a photon traveling at the speed of light c and a frequency ν will have a wavelength λ given by <span>λ=<span>cν</span></span>λ will have an energy given by <span>E=<span><span>hc</span>λ</span></span><span>λ=657</span> nm. This will be <span>E=<span><span>(6.626×<span>10<span>−34</span></span>)(2.998×<span>108</span>)</span><span>(657×<span>10<span>−9</span></span>)</span></span>=3.0235×<span>10<span>−19</span></span>J</span>
So we now know the energy of one photon of wavelength 657 nm. To find out how many photons are in a laser pulse of 0.363 Joules, we simply divide the pulse energy by the photon energy or <span>N=<span><span>E<span>pulse </span></span><span>E<span>photon</span></span></span>=<span>0.363<span>3.0235×<span>10<span>−19</span></span></span></span>=1.2×<span>1018</span></span>So there would be <span>1.2×<span>1018</span></span><span> photons of wavelength 657 nm in a pulse of laser light of energy 0.363 Joules.</span>
Answer:
Fe2(SO4)3 + 3BaCl2 → 2FeCl3 + 3BaSO4
The substance with the higher freezing point depression is CaCl2.
<h3>What is water's freezing point?</h3>
Water freezes at 0° C in normal conditions but once water is mixed with other substances this temperature can change.
<h3>How does the freezing point change?</h3>
As previously mentioned, the freezing point changes according to the substance water is mixed with, here are the changes for the listed substances:
- Water with NaCl: -3.72 °C
- Water with CaCl2: -5.58 °C
- Water with C12H22O11 (Sucrose): -0.68 °C
- Pure water: No changes
Based on this, the one that has the greatest freezing point depression is CaCl2.
Learn more about freezing in: brainly.com/question/14131507