Skip to main content
Ch.7 - Thermochemistry
Chapter 7, Problem 65

Nitromethane (CH3NO2) burns in air to produce significant amounts of heat. 2 CH3NO2(l ) + 32 O2( g)¡2 CO2( g) + 3 H2O(l ) + N2( g) ΔH °rxn = -1418 kJ How much heat is produced by the complete reaction of 10.47 kg of nitromethane?

Verified step by step guidance
1
Convert the mass of nitromethane from kilograms to grams by multiplying by 1000, since 1 kg equals 1000 grams.
Calculate the number of moles of nitromethane by using its molar mass. The molar mass of CH3NO2 is approximately 61 g/mol. Use the formula: number of moles = mass (g) / molar mass (g/mol).
Use the stoichiometry of the balanced chemical equation to determine the amount of heat produced per mole of nitromethane. According to the equation, 2 moles of CH3NO2 produce -1418 kJ of heat.
Calculate the total heat produced by multiplying the number of moles of nitromethane by the heat produced per mole from the stoichiometry.
Ensure the final answer is expressed in kilojoules (kJ) as the heat produced by the reaction.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Stoichiometry

Stoichiometry is the calculation of reactants and products in chemical reactions based on the balanced chemical equation. It allows us to determine the proportions of substances involved in a reaction, which is essential for calculating how much heat is produced when a specific amount of a reactant, like nitromethane, is consumed.
Recommended video:
Guided course
01:16
Stoichiometry Concept

Enthalpy Change (ΔH)

Enthalpy change (ΔH) represents the heat absorbed or released during a chemical reaction at constant pressure. In this case, the negative value of ΔH indicates that the reaction is exothermic, meaning it releases heat. Understanding ΔH is crucial for calculating the total heat produced from the combustion of nitromethane.
Recommended video:
Guided course
02:34
Enthalpy of Formation

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). To calculate the heat produced from a given mass of nitromethane, we first need to convert the mass of nitromethane (10.47 kg) into moles using its molar mass. This conversion is vital for applying stoichiometry and determining the total heat released.
Recommended video:
Guided course
02:11
Molar Mass Concept
Related Practice
Textbook Question

Determine whether each process is exothermic or endothermic and indicate the sign of ΔH. a. natural gas burning on a stove b. isopropyl alcohol evaporating from skin c. water condensing from steam Indicate the sign of ΔH for the following processes.

Textbook Question

Determine whether each process is exothermic or endothermic and indicate the sign of ΔH. a. dry ice evaporating b. a sparkler burning c. the reaction that occurs in a chemical cold pack used to ice athletic injuries

Textbook Question

What mass of natural gas (CH4) must burn to emit 352 kJ of heat? CH4( g) + 2 O2( g)¡CO2( g) + 2 H2O( g) ΔH °rxn = -802.3 kJ

Textbook Question

Titanium reacts with iodine to form titanium(III) iodide, emitting heat. 2 Ti(s) + 3 I2( g)¡2 TiI3(s) ΔH °rxn = -839 kJ Determine the mass of titanium that react if 2.38 * 103 kJ of heat is emitted by the reaction.

Textbook Question

The propane fuel (C3H8) used in gas barbeques burns according to the thermochemical equation: C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(g) ΔH°rxn = –2044 kJ If a pork roast must absorb 1.6×103 kJ to fully cook, and if only 10% of the heat produced by the barbeque is actually absorbed by the roast, what mass of CO2 is emitted into the atmosphere during the grilling of the pork roast?

7
views
Textbook Question

Charcoal is primarily carbon. Determine the mass of CO2 produced by burning enough carbon (in the form of charcoal) to produce 5.00×102 kJ of heat. C(s) + O2(g) → CO2(g) ΔH°rxn = –393.5 kJ

1
views