Given the reaction shown below, calculate:
(a) The amount of NO2, in grams, generated from reactants if 300.23 kJ of heat energy is released during the course of the reacton.
(b) The heat energy released if 33.23 grams of O2 is consumed in the reaction.
2 NO(g) + O2(g) „_ 2 NO2(g) ƒ´Hrxn = ¡V114.2 kJ
To solve both parts of the problem, we need to use stoichiometry and the given enthalpy change value.
(a) To calculate the amount of NO2 generated from reactants given the heat energy released, we'll use the enthalpy change value.
From the balanced equation, we know that the enthalpy change of the reaction is -114.2 kJ for the formation of 2 moles of NO2.
To convert kJ to grams, we need to know the molar mass of NO2. The molar mass of NO2 is 46.01 g/mol.
Using the given enthalpy change and molar mass, we can set up the following proportion:
-114.2 kJ / 2 moles NO2 = x kJ / 46.01 g NO2
Solving for x, we get:
x = (-114.2 kJ * 46.01 g NO2) / (2 moles NO2)
x ≈ -2626.17 kJ * g / mole
Therefore, approximately -2626.17 kJ of heat energy is released when 1 mole of NO2 is formed.
(b) To calculate the heat energy released when consuming 33.23 grams of O2, we'll use the same proportion as in part (a).
From the balanced equation, we know that the enthalpy change of the reaction is -114.2 kJ for the formation of 1 mole of NO2.
We'll use the molar mass of O2, which is 32 g/mol, to convert grams of O2 to moles.
Using the given mass of O2 and the molar mass, we can set up the following proportion:
-114.2 kJ / 1 mole O2 = x kJ / 32 g O2
Solving for x, we get:
x = (-114.2 kJ * 32 g O2) / (1 mole O2)
x ≈ -3654.4 kJ * g / mole
Therefore, approximately -3654.4 kJ of heat energy is released when consuming 33.23 grams of O2 in the reaction.
To solve these problems, you'll need to apply the concept of stoichiometry and energy changes in chemical reactions.
(a) To calculate the amount of NO2 generated from reactants when 300.23 kJ of heat energy is released, we need to use the information given about the enthalpy change of the reaction.
1. First, write down the balanced equation for the reaction:
2 NO(g) + O2(g) -> 2 NO2(g)
2. Use the enthalpy change given: ΔH_rxn = -114.2 kJ (the negative sign indicates heat being released).
Keep in mind that this value is for the molar amount of reaction given, so we'll need to use it in terms of moles.
3. Determine the molar amount of NO2 using the stoichiometric coefficients:
According to the balanced equation, 2 moles of NO2 are produced for every 2 moles of NO and 1 mole of O2 consumed.
4. Use the equation: ΔH_rxn = (ΔH_rxn/moles of reaction) * moles of NO2
Rearranging the equation, we get: moles of NO2 = (moles of reaction * ΔH_rxn) / ΔH_rxn
5. Calculate the moles of reaction:
Since we're given the heat energy released, we need to calculate the moles of reaction by using the equation:
moles of reaction = heat energy released / ΔH_rxn
Convert the given heat energy into kJ by dividing by 1000.
6. Finally, convert the moles of NO2 to grams using the molar mass of NO2.
(b) To calculate the heat energy released if 33.23 grams of O2 is consumed in the reaction, we need to reverse the process.
1. Begin with the balanced equation and the given amount of O2.
2. Again, determine the moles of O2 using its molar mass.
3. Use the stoichiometry to determine the moles of NO2 produced. Refer to the balanced equation, which indicates that for every mole of O2 consumed, 2 moles of NO2 are produced.
4. Convert the moles of NO2 to grams using the molar mass of NO2.
These steps should help you calculate the values for both (a) and (b). Remember to keep track of units and perform any necessary conversions along the way.