Explore BrainMass
Share

Explore BrainMass

    Energy, q, w, Enthalpy, and Stoichiometry II and Specific Heat

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    Problem 1 - Energy, q, w, Enthalpy, and Stoichiometry
    Consider the following reaction:

    2Mg(s)+O2(g)>>2MgO(s)ΔH = -1204kJ

    1) Is this reaction exothermic or endothermic?

    2) Calculate the amount of heat transferred when 2.1 g of Mg(s) reacts at constant pressure.
    Express your answer using two significant figures.

    3)How many grams of MgO are produced during an enthalpy change of -94.0 kJ ?

    4)How many kilojoules of heat are absorbed when 7.80 g of MgO(s) is decomposed into Mg(s) and O2(g) at constant pressure?

    Problem 2 - Specific Heat

    The specific heat of iron metal is 0.450 J/g*K
    How many J of heat are necessary to raise the temperature of a 1.10 - Kg block of iron from 26.0 Celsius degrees to 88.0 Celsius degrees?

    © BrainMass Inc. brainmass.com October 10, 2019, 12:46 am ad1c9bdddf
    https://brainmass.com/chemistry/reaction-stoichiometry/energy-enthalpy-stoichiometry-specific-heat-306973

    Solution Preview

    Problem 1 - Energy, q, w, Enthalpy, and Stoichiometry
    Consider the following reaction:

    2Mg(s) + O2(g) >> 2MgO(s) ΔH = -1204kJ

    1) Is this reaction exothermic or endothermic?
    Since ΔH is negative, the reaction is exothermic.

    2) Calculate the amount of heat transferred when 2.1 g of Mg(s) reacts at constant pressure.
    Express your answer using two ...

    Solution Summary

    Energy, q, w, enthalpy, and stoichiometry II and specific heat are examined. The expert determines if a reaction is exothermic or endothermic.

    $2.19