Given the reaction 2NO2 + 2H2O → 2HNO3 + NO, if 4.60 g of NO2 reacts with excess H2O, what is the theoretical yield of NO (in grams)? (Molar masses: NO2 = 46.0 g/mol, NO = 30.0 g/mol)

• A. 1.50 g
• B. 4.60 g
• C. 2.30 g
• D. 3.00 g

Answer: (A)

Verified step by step guidance

1. Identify the given information: mass of NO2 = 4.60 g, molar mass of NO2 = 46.0 g/mol, molar mass of NO = 30.0 g/mol, and the balanced chemical equation: 2NO2 + 2H2O → 2HNO3 + NO.
2. Calculate the number of moles of NO2 reacted using the formula: \(\text{moles of NO2} = \frac{\text{mass of NO2}}{\text{molar mass of NO2}} = \frac{4.60}{46.0}\).
3. Use the stoichiometric coefficients from the balanced equation to find the moles of NO produced. According to the equation, 2 moles of NO2 produce 1 mole of NO, so: \(\text{moles of NO} = \frac{1}{2} \times \text{moles of NO2}\).
4. Convert the moles of NO to grams using its molar mass: \(\text{mass of NO} = \text{moles of NO} \times 30.0\) g/mol.
5. The result from step 4 gives the theoretical yield of NO in grams.