How many grams of N2(g) would have to react to produce 19.5 kJ of energy

React with what?

To determine the grams of N2(g) needed to produce 19.5 kJ of energy, we need to use the balanced equation for the reaction and the molar enthalpy of that reaction.

Here's the step-by-step process to find the answer:

1. Identify the balanced chemical equation for the reaction involving N2(g). Make sure the equation is balanced (same number of atoms on both sides).
Example: N2(g) + 3H2(g) -> 2NH3(g)

2. Determine the molar enthalpy (ΔH) of the reaction.
The molar enthalpy can be obtained from reference tables or calculated using experimental data. Make sure the enthalpy value corresponds to the direction of the reaction.
Example: ΔH = -46 kJ/mol (Note: The negative sign indicates the release of energy.)

3. Calculate the molar amount of N2 in the reaction.
Based on the balanced equation, the stoichiometry tells us that 1 mole of N2 reacts with a certain amount of energy released or absorbed.

4. Use the molar enthalpy (ΔH) to calculate the moles of N2 needed to produce the desired energy.
Apply the equation: moles N2 = (energy released/absorbed) / molar enthalpy.
Convert the given energy value (19.5 kJ) to joules (J) by multiplying it by 1000 (1 kJ = 1000 J).
Example: moles N2 = (19.5 kJ * 1000 J/kJ) / (-46 kJ/mol)

5. Convert the moles of N2 to grams.
To convert moles to grams, use the molar mass of N2.
The molar mass of N2 is approximately 28 g/mol.
Example: grams N2 = moles N2 * molar mass of N2

By following this process, you can calculate the grams of N2 required to produce 19.5 kJ of energy in the given reaction.