The meals-ready-to-eat (MREs) in the military can be heated on a flameless heater. You can purchase a similar product called “Heater Meals”.  Just pour water into the heater unit, wait a few minutes, and you have a hot meal. The source of energy in the heater is the exothermic reaction of magnesium with water:                                        Mg(s) + 2 H2O(ℓ) → Mg(OH)2(s) + H2(g)                                                                ΔHf° (kJ/mol)                        Mg(s)                                0                        Mg(OH)2(s)             –924.5                        H2O(ℓ)                       –285.8                        H2(g)                                 0          Calculate the mass, in g, of magnesium needed to supply the energy required to warm 25.0 mL of water from 25.0 °C to 85.0 °C. The density of water is 1.00 g/mL, and its specific heat capacity is 4.184 J/g∙°C. 0.432 g 0.126 g 1.244 g 2.740 g 0.745 g

General Chemistry - Standalone book (MindTap Course List)
11th Edition
ISBN:9781305580343
Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; Darrell
Publisher:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; Darrell
Chapter6: Thermochemisty
Section: Chapter Questions
Problem 6.137QP: When solid iron burns in oxygen gas (at constant pressure) to produce Fe2O3(s), 1651 kJ of heat is...
icon
Related questions
icon
Concept explainers
Question

The meals-ready-to-eat (MREs) in the military can be heated on a flameless heater. You can purchase a similar product called “Heater Meals”.  Just pour water into the heater unit, wait a few minutes, and you have a hot meal. The source of energy in the heater is the exothermic reaction of magnesium with water:

                                       Mg(s) + 2 H2O(ℓ) → Mg(OH)2(s) + H2(g)

                                                               ΔHf° (kJ/mol)

                       Mg(s)                                0

                       Mg(OH)2(s)             –924.5

                       H2O(ℓ)                       –285.8

                       H2(g)                                 0         

Calculate the mass, in g, of magnesium needed to supply the energy required to warm 25.0 mL of water from 25.0 °C to 85.0 °C. The density of water is 1.00 g/mL, and its specific heat capacity is 4.184 J/g∙°C.

0.432 g

0.126 g

1.244 g

2.740 g

0.745 g

 

 

 

Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 5 steps with 7 images

Blurred answer
Knowledge Booster
Thermochemistry
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.
Similar questions
Recommended textbooks for you
General Chemistry - Standalone book (MindTap Cour…
General Chemistry - Standalone book (MindTap Cour…
Chemistry
ISBN:
9781305580343
Author:
Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; Darrell
Publisher:
Cengage Learning
Chemistry & Chemical Reactivity
Chemistry & Chemical Reactivity
Chemistry
ISBN:
9781337399074
Author:
John C. Kotz, Paul M. Treichel, John Townsend, David Treichel
Publisher:
Cengage Learning
Chemistry & Chemical Reactivity
Chemistry & Chemical Reactivity
Chemistry
ISBN:
9781133949640
Author:
John C. Kotz, Paul M. Treichel, John Townsend, David Treichel
Publisher:
Cengage Learning
Chemistry: The Molecular Science
Chemistry: The Molecular Science
Chemistry
ISBN:
9781285199047
Author:
John W. Moore, Conrad L. Stanitski
Publisher:
Cengage Learning
Chemistry: Principles and Practice
Chemistry: Principles and Practice
Chemistry
ISBN:
9780534420123
Author:
Daniel L. Reger, Scott R. Goode, David W. Ball, Edward Mercer
Publisher:
Cengage Learning