Nitromethane (CH3NO2), sometimes used as a fuel in drag racers, burns according to the following equation. How much heat is released by burning 100.0 g of nitromethane? 4 CH3NO2(l) + 7 O2(g) → 4 CO2(g) + 6 H2O(g) + 4 NO2(g) ΔH° = -2441.6 kJ

Verified step by step guidance

1. Step 1: Determine the molar mass of nitromethane (CH3NO2). Calculate it by adding the atomic masses of all the atoms in the molecule: C (12.01 g/mol) + H (1.01 g/mol * 3) + N (14.01 g/mol) + O (16.00 g/mol * 2).
2. Step 2: Convert the given mass of nitromethane (100.0 g) to moles using its molar mass. Use the formula: moles = mass / molar mass.
3. Step 3: Use the stoichiometry of the balanced chemical equation to find the moles of reaction. According to the equation, 4 moles of CH3NO2 release -2441.6 kJ of heat.
4. Step 4: Calculate the heat released for the moles of nitromethane you have. Use the proportion: (moles of CH3NO2 / 4 moles) * -2441.6 kJ.
5. Step 5: The result from Step 4 will give you the amount of heat released when 100.0 g of nitromethane is burned.

Key Concepts

Stoichiometry

Stoichiometry is the calculation of reactants and products in chemical reactions based on the balanced equation. It allows us to determine the amount of substance consumed or produced in a reaction. In this case, it helps us relate the mass of nitromethane burned to the heat released, using the coefficients from the balanced equation.

Enthalpy Change (ΔH)

Enthalpy change (ΔH) represents the heat content change during a chemical reaction at constant pressure. A negative ΔH indicates that the reaction is exothermic, meaning it releases heat. In the provided equation, the ΔH° of -2441.6 kJ signifies that burning 4 moles of nitromethane releases this amount of energy, which is crucial for calculating the heat released for a specific mass.

Molar Mass

Molar mass is the mass of one mole of a substance, expressed in grams per mole (g/mol). For nitromethane (CH3NO2), calculating its molar mass is essential to convert the given mass (100.0 g) into moles. This conversion is necessary to apply stoichiometry and determine the total heat released based on the enthalpy change associated with the combustion of nitromethane.