Answer:
K = 0.2
Explanation:
Based on the chemical dissociation of N₂O₄:
N₂O₄ ⇄ 2NO₂
The equilibrium constant, K, of the reaction is:
K = [NO₂]² / [N₂O₄]
Now, if 20% of N₂O₄ is dissociated, 80% remains as N₂O₄ = 0.8mol/L = 0.8M
as 20% is dissociated, 0.2moles of N₂O₄ were dissociated and 0.2*2 = 0.4mol/L of NO₂ are produced.
Replacing in K:
K = [0.4M]² / [0.8M]
<h3>K = 0.2</h3>
Since there are 23 days and 24 hours in each day, you multi-ply them and get 552 hours. Since each hours is 60 minutes, 552*60 is 33120 minutes. Since one minute is 60 seconds, 60*33120 is 1,987,200 seconds. Therefore, there are 1,987,200 seconds in 23 days.
Two independent variables could change at the same time, and you would not know which variable affected the dependent variable
Answer : The correct option is (c) 
Explanation :
The given balanced chemical reaction is,

From the balanced chemical reaction, we conclude that
As, 3 moles of
react to give 2 mole of 
So, 1 mole of
react to give
moles of 
Thus, the conversion factor needed to convert the number of moles of
to the number of moles of
produced is 
Hence, the correct option is (c) 