-CORRECTION-

N2 + O2 --> 2 NO change in heat (delta H)= 43.2 kcal

based on the reaction, which statement is true?
a) 43.2 kcal are consumed when 1.00g of O2 reacts
b) 43.2 kcal are consumed when 1.00g of N2 reacts
c) 43.2 kcal are consumed when 1.00g of NO is produced
d) 43.2 kcal are consumed when 1.00 mole of O2 reacts

I think it is D because the heat is used when the reaction occurs and the product is made. Is this correct?

***I actually meant to write C not D. When I copied the question over from my worksheet there were 5 answers and I took one out because I knew it was not correct and I accidentally wrote the letter for the answer on my paper and not what I wrote on here.

What I was trying to say for my reason is that the energy is not used until the two products react together to form 2 NO. So when 2 NO is produced, the energy is released. None of the possible answers say when they both react so that's why I thought it would be the product. But I really don't know. I just don't understand Chemistry. So if it is actually D, what is the reason?

The FIRST think you need to understand about chemistry is that the reaction is not between grams but between moles. Let me point out some things that are common to all the answers. The delta H is positive which means that the reaction is endothermic (heat is consumed in the reaction) so nothing can be eliminated on that point. Answers a, b, and c are wrong because they have grams in them. D is the only answer that uses moles; therefore, D is correct. So when 1 mole N2 reacts with 1 mole of O2 to form 2 moles NO, 43.2 kcal are consumed. As for both reactants not being used in the answer consider that IF 1 mole O2 is consumed then 1 mole N2 MUST have been consumed also AND 2 moles NO must have been produced. But the secret to the answer (from those you listed since I don't know the one you didn't post) is that D is the only one that lists moles.

I wanted to point out in your clarified explanation that when 2 NO moles are produced, the energy is NOT released. It is CONSUMED.

Actually, the correct answer is C) 43.2 kcal are consumed when 1.00g of NO is produced.

In the given reaction, N2 (nitrogen gas) reacts with O2 (oxygen gas) to produce 2 moles of NO (nitric oxide). The change in heat (ΔH) for this reaction is 43.2 kcal.

To determine the correct statement, we need to consider the stoichiometry of the reaction and the given ΔH value.

From the balanced equation, we can see that for every 2 moles of NO produced, 1 mole of N2 reacts. Therefore, the reaction consumes 43.2 kcal when 1 mole of N2 reacts.

However, the question asks for the statement that is true when 1.00g of a specific substance is produced. To answer this, we can use the molar mass of NO, which is 30.01 g/mol.

Using the molar mass, we can calculate the number of moles of NO produced when 1.00g of NO is formed:

moles of NO = mass of NO / molar mass of NO
moles of NO = 1.00g / 30.01 g/mol ≈ 0.0333 mol

Since 2 moles of NO are produced when 1 mole of N2 reacts, the moles of N2 reacting can be calculated as:

moles of N2 = 2 × moles of NO = 2 × 0.0333 mol ≈ 0.0667 mol

Now, let's calculate the consumed heat (ΔH) when 0.0667 mol of N2 reacts:

ΔH (kcal) = ΔH (kcal/mol) × moles of N2
ΔH (kcal) = 43.2 kcal × 0.0667 mol ≈ 2.88104 kcal

Since the given reaction consumes 2.88104 kcal when 0.0667 mol of N2 reacts, it follows that 43.2 kcal are consumed when 1.00g of NO is produced.

Therefore, the correct answer is C) 43.2 kcal are consumed when 1.00g of NO is produced.

The correct answer is actually C) 43.2 kcal are consumed when 1.00g of NO is produced. Let me explain the reasoning behind this.

In the given reaction, N2 + O2 → 2 NO, the stoichiometric coefficients of the reactants and products indicate the relative amounts of each substance involved in the reaction.

The change in heat (ΔH) of the reaction is given as 43.2 kcal. This means that 43.2 kcal of energy are either released or consumed during the reaction.

To determine which statement is true, we need to consider the molar mass of each substance involved in the reaction:

- The molar mass of N2 is approximately 28 g/mol.
- The molar mass of O2 is approximately 32 g/mol.
- The molar mass of NO is approximately 30 g/mol.

Now, let's examine the options:

a) 43.2 kcal are consumed when 1.00g of O2 reacts.
To calculate the amount of O2 in moles:
1.00 g O2 / (32 g/mol) = 0.03125 mol O2

Since the stoichiometric coefficient of O2 in the balanced equation is 1, we can conclude that the consumption of 0.03125 mol of O2 would correspond to a change in heat of 43.2 kcal. Therefore, option a) is not correct.

b) 43.2 kcal are consumed when 1.00g of N2 reacts.
To calculate the amount of N2 in moles:
1.00 g N2 / (28 g/mol) = 0.03571 mol N2

Since the stoichiometric coefficient of N2 in the balanced equation is 1, we can conclude that the consumption of 0.03571 mol of N2 would correspond to a change in heat of 43.2 kcal. Therefore, option b) is not correct.

c) 43.2 kcal are consumed when 1.00g of NO is produced.
To calculate the amount of NO in moles:
1.00 g NO / (30 g/mol) = 0.03333 mol NO

Since the stoichiometric coefficient of NO in the balanced equation is 2, we can conclude that the production of 0.03333 mol of NO would correspond to a change in heat of 43.2 kcal. Therefore, option c) is correct.

d) 43.2 kcal are consumed when 1.00 mole of O2 reacts.
This option is not directly related to the given information. We cannot determine the amount of heat released or consumed based solely on the amount of O2 in moles. Therefore, option d) is not correct.

In summary, based on the given reaction, statement c) is true. 43.2 kcal of energy are consumed when 1.00g of NO is produced.