What is the mass change in grams for the reaction 2 NO₂(g)→ N₂O₄(g)? The enthalpy for the reaction is -57.2 kJ. A)-6.36 × 10^-13 g B)-6.36 × 10^-10 g C)-1.91 × 10^-7 g D)-1.91 × 10^-4 g

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Quizplus · Accepted Answer

To solve this problem, we need to use the equation: Δn = moles of products - moles of reactants Δn = (1 mol N₂O₄ - 2 mol NO₂) = -1 mol Then, we can use the equation: Δn = Δm / Mr where Δm is the mass change in grams and Mr is the molar mass of the compound. Δm = Δn * Mr = -1 * (92.0 + 32.1 + 16.0*14) g/mol = -6.36 × 10^-10 g Therefore, the mass change is -6.36 × 10^-10 g or -6.36 × 10^-10 g (rounded to two significant figures). The best choice is B.

What Is the Mass Change in Grams for the Reaction