Answer:
The correct answer is option E.
Explanation:
Structures for the reactants and products are given in an aimage ;
Number of double bonds in oxygen gas molecule = 1
Number of double bonds in nitro dioxide gas molecule = 1
Number of single bond in in nitro dioxide gas molecule = 1
Number of triple bonds in nitrogen gas molecule = 1

![\Delta H=[2 mol\times \Delta H_{f,NO_2}]-[1 mol\times \Delta H_{f,N_2}-2 mol\times \Delta H_{f,O_2}]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B2%20mol%5Ctimes%20%5CDelta%20H_%7Bf%2CNO_2%7D%5D-%5B1%20mol%5Ctimes%20%5CDelta%20H_%7Bf%2CN_2%7D-2%20mol%5Ctimes%20%5CDelta%20H_%7Bf%2CO_2%7D%5D)

(pure element)
(pure element )

The enthalpy of the given reaction is 15.86 kcal.
Explanation:
By losing or gaining electrons from its outermost orbit
You’ve not put anything below so I’m not sure what the options are but the relative charge of a proton is +1
1 Kj ------------- 1000 J
?? --------------- 10 J
10 x 1 / 1000 => 0.01 Kj
Answer:
23.8
Explanation:
Formula
weight % = weight of solute/ weight of solution x 100
weight of solution = weight of salt + weight of water
weight of solution = 1.62 lb + 5.20 lb = 6.82 lb
weight % = 1.62 / 6,82 x 100
weight % = 0.238 x 100
weight % = 23.8