<u>Answer:</u> The Henry's law constant for oxygen gas in water is 
<u>Explanation:</u>
To calculate the molar solubility, we use the equation given by Henry's law, which is:

where,
= Henry's constant = ?
= solubility of oxygen gas = 
= partial pressure of oxygen gas = 2.1 atm
Putting values in above equation, we get:

Hence, the Henry's law constant for oxygen gas in water is 
I think It’s 55 but that’s just me
Answer:
Explanation:Are You From Milo?
Answer:
the HOMO-LUMO energy difference in ethylene is greater than that of cis,trans−1,3−cyclooctadiene
Explanation:
The λmax is the wavelength of maximum absorption. We could use it to calculate the HOMO-LUMO energy difference as follows:
For ethylene
E= hc/λ= 6.63×10^-34×3×10^8/170×10^-9= 1.17×10^-18J
For cis,trans−1,3−cyclooctadiene
E= hc/λ=6.63×10^-34×3×10^8/230×10^-9=8.6×10^-19J
Therefore, the HOMO-LUMO energy difference in ethylene is greater than that of cis,trans−1,3−cyclooctadiene