What mass of natural gas (CH 4 ) must burn to emit 267 kJ of heat? CH 4 (g) + 2 O 2 (g) → CO 2 (g) + 2 H 2 O(g) ΔH° rxn = –802.3 kJ

Hey everyone in this example, we need to find the mass of carbon monoxide produced if the reaction absorbs 32.11 kg of heat. So that's what we're going to begin our equation with 32.11 kg joules. And we're going to recognize that according to the given equation for our reaction, We have an entropy value of 42 kg jewels. So we're going to say that for 42 kg jules, looking at the stock geometry of our carbon monoxide, we have one mole of carbon monoxide that is produced. And so now we can cancel out our units of kilo jewels. And now that we're at moles of carbon monoxide, we want to get two g of carbon monoxide. And so we're going to recall from the periodic table are molar mass for carbon monoxide, Which we see as 28.01 g of carbon monoxide for one mole of carbon monoxide. So this allows us to cancel out moles leaving us with grams of carbon monoxide, which is what we want. And so when we type this into our calculators, we get a value equal to 21.41 g of carbon monoxide that is produced from the given reaction. When it absorbs 32.11 kg joules of heat. And so this will be our final answer to complete this example. So, I hope that everything we reviewed was clear. If you have any questions, please leave them down below and I will see everyone in the next practice video

Ch.6 - Thermochemistry

All textbooks

Tro 4th Edition

Ch.6 - Thermochemistry

Problem 60

Previous problem

Next problem

Chapter 6, Problem 60

What mass of natural gas (CH₄) must burn to emit 267 kJ of heat? CH₄(g) + 2 O₂(g) → CO₂(g) + 2 H₂O(g) ΔH°_rxn = –802.3 kJ

Verified step by step guidance

Identify the given information: The reaction is CH₄(g) + 2 O₂(g) → CO₂(g) + 2 H₂O(g) with ΔH°rxn = -802.3 kJ.

Understand that the negative sign in ΔH°rxn indicates that the reaction is exothermic, meaning it releases 802.3 kJ of heat per mole of CH₄ burned.

Set up a proportion to find the moles of CH₄ needed to release 267 kJ of heat: (1 mole CH₄ / 802.3 kJ) = (x moles CH₄ / 267 kJ).

Solve the proportion for x to find the moles of CH₄ required to release 267 kJ of heat.

Convert the moles of CH₄ to mass using the molar mass of CH₄ (16.04 g/mol): mass = moles × molar mass.

Verified Solution

Video duration:

This video solution was recommended by our tutors as helpful for the problem above.

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. It involves using balanced chemical equations to determine the relationships between the amounts of substances consumed and produced. In this case, stoichiometry will help relate the amount of CH4 burned to the heat emitted based on the reaction's enthalpy change.

Enthalpy Change (ΔH)

Enthalpy change (ΔH) is a measure of the heat absorbed or released during a chemical reaction at constant pressure. A negative ΔH indicates that the reaction is exothermic, meaning it releases heat. For the combustion of methane (CH4), the given ΔH of -802.3 kJ indicates that burning one mole of CH4 releases 802.3 kJ of heat, which is crucial for calculating the mass needed to emit a specific amount of heat.

Molar Mass

Molar mass is the mass of one mole of a substance, expressed in grams per mole (g/mol). For CH4, the molar mass is approximately 16.04 g/mol. Knowing the molar mass is essential for converting between moles of CH4 and grams, allowing us to determine how much mass is required to produce the desired heat output based on the stoichiometric calculations.

Recommended video:

Molar Mass Concept

Related Practice

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.

549

views

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

578

views

Open Question

Consider the thermochemical equation for the combustion of acetone (C3H6O), the main ingredient in nail polish remover: C3H6O(l) + 4 O2(g) → 3 CO2(g) + 3 H2O(g) ΔH°rxn = -1790 kJ. If a bottle of nail polish remover contains 177 mL of acetone, how much heat is released by its complete combustion? The density of acetone is 0.788 g/mL.

Textbook Question

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 5.56 kg of nitromethane?

2922

views

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 1.55×10³ kJ of heat is emitted by the reaction.

1684

views

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?

6036

views

What mass of natural gas (CH4) must burn to emit 267 kJ of heat? CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g) ΔH°rxn = –802.3 kJ

Verified Solution

Key Concepts

Stoichiometry

Enthalpy Change (ΔH)

Molar Mass

What mass of natural gas (CH₄) must burn to emit 267 kJ of heat? CH₄(g) + 2 O₂(g) → CO₂(g) + 2 H₂O(g) ΔH°_rxn = –802.3 kJ