<u>Answer:</u> The mass of nitrogen gas reacted to produce given amount of energy is 5.99 grams.
<u>Explanation:</u>
The given chemical reaction follows:

We know that:
Molar mass of nitrogen gas = 28 g/mol
We are given:
Enthalpy change of the reaction = 14.2 kJ
To calculate the mass of nitrogen gas reacted, we use unitary method:
When enthalpy change of the reaction is 66.4 kJ, the mass of nitrogen gas reacted is 28 grams.
So, when enthalpy change of the reaction is 14.2 kJ, the mass of nitrogen gas reacted will be = 
Hence, the mass of nitrogen gas reacted to produce given amount of energy is 5.99 grams.
Answer:
The correct answer is there is a mistake in the calculation. The second law of thermodynamics state that in any spontaneous process there is an increase in the entropy of the universe.
Explanation:
According to the second law a reaction will occur in a system spontaneously if the total entropy of both system and surrounding increases during the reaction.That means in case of spontaneous reaction entropy change is always positive.
But according to the question the reaction H2+F2=2HF is spontaneous in all temperature.So according to the second law of thermodynamics i can say that my classmate made a mistake in calculation that"s why his result for entropy change comes negative.
Moles = n/v where n is the moles of solute and v being the liters of solution.
We can put in the information provided to find the molarity.
Moles = .45/3.0 = .15
So we now know that the molarity of that solution is .15!
I hope I helped you :). Make sure to memorize that formula because it's not that hard as long as you know what to plug in.
Mass number...use da textbook bra
Answer:
3 moles of oxygen at STP will occupy a volume of 3×22. 4=67. 2 L.
Explanation: