Suppose that 0.450 of methane,CH4(g) , is reacted with 0.600 of fluorine, F2(g), forming CF(g) and HF(G) as sole products. Assuming that the reaction occurs at constant pressure, how much heat is released?
You don't have any units.
who cares solve the damn problem
To determine the amount of heat released during the reaction, we need to calculate the heat of reaction (∆H) using the balanced chemical equation and the standard enthalpies of formation (∆Hf) for the reactants and products involved.
First, let's write the balanced chemical equation for the reaction between methane (CH4) and fluorine (F2):
CH4(g) + 2F2(g) -> CF(g) + 4HF(g)
Now, we need to find the standard enthalpies of formation for each compound involved in the reaction:
∆Hf(CH4) = -74.6 kJ/mol
∆Hf(F2) = 0 kJ/mol
∆Hf(CF) = +142.2 kJ/mol
∆Hf(HF) = -270.3 kJ/mol
Since the reaction occurs at constant pressure, the heat released (∆H) is equal to the difference in the enthalpies of formation between the products and the reactants.
∆H = (∆Hf(products)) - (∆Hf(reactants))
∆H = [∆Hf(CF) + 4∆Hf(HF)] - [∆Hf(CH4) + 2∆Hf(F2)]
∆H = [142.2 kJ/mol + (4 * -270.3 kJ/mol)] - [(-74.6 kJ/mol) + (2 * 0 kJ/mol)]
∆H = 568.8 kJ/mol - 74.6 kJ/mol
∆H = 494.2 kJ/mol
Therefore, the heat released during the reaction is 494.2 kJ.
To calculate the heat released in the reaction, we need to know the enthalpy change per mole for the reaction. This information is typically provided as the standard enthalpy of formation (ΔH°f) for the substances involved.
Let's find the necessary enthalpy values:
ΔH°f(CH₄(g)) = -74.87 kJ/mol
ΔH°f(F₂(g)) = 0 kJ/mol
ΔH°f(CF(g)) = -92.3 kJ/mol
ΔH°f(HF(g)) = -272.2 kJ/mol
Now, let's balance the chemical equation for the reaction:
CH₄(g) + 2F₂(g) → CF(g) + 2HF(g)
From the balanced equation, we see that one mole of methane reacts with 2 moles of fluorine to produce 1 mole of CF and 2 moles of HF.
Given:
0.450 mol of CH₄
0.600 mol of F₂
Since 1 mole of CH₄ reacts to produce 92.3 kJ of heat, the heat released can be calculated as follows:
0.450 mol CH₄ × (-92.3 kJ/mol) = -41.54 kJ
Therefore, the reaction releases 41.54 kJ of heat. Since the reaction is exothermic, the negative sign indicates the release of heat.