Assignment: Enthalpy, Energy, and Temperature Change

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Complete the following thermochemistry problems – show all of your work as you set up equations and make calculations.

    1. The Travis Scott promotional meal at McDonald’s had [latex]1180[/latex] Calories (note the capital letter- this indicates nutritional Calories). Find the amount of energy in Joules.
    2. A [latex]9.00[/latex] g nugget of pure gold absorbed [latex]276[/latex] J of heat. What was the final temperature of the gold if the initial temperature was [latex]25.0[/latex]° C? The specific heat of gold is [latex]0.129[/latex] J/(g °C).
    3. A sample of silver with a mass of [latex]63.3[/latex] g is heated to a temperature of [latex]384.4[/latex] K and placed in a container of water at [latex]290.0^{\circ}[/latex]K. The final (equilibrium) temperature of the silver and water is [latex]292.4^{\circ}[/latex]K. What volume of water is in the container? The specific heat of silver is [latex]0.235[/latex] J/(g °C).
    4. NSU Chemistry 101L class conducted an experiment in which a measured amount of [latex]\text{NaOH}[/latex] is dissolved in water inside a foam cup calorimeter. A student collected data throughout the experiment. Calculate [latex]\Delta\text{H}[/latex] for the process in kJ/mol.
      • Data table from the experiment:
        Mass of NaOH + weigh boat 14.13 g
        Mass of weigh boat 0.70 g
        Mass of NaOH
        Mass of foam cup+water 109.85 g
        Mass of foam cup 10.25 g
        Mass of water
        Initial temp of water 24.5°C
        Final temp of water 36.8°C
        Change in temperature (ΔT)
    5. You can light a charcoal grill in about a minute. If the grill is prepared using one [latex]20[/latex] pound bag of charcoal (primarily carbon) and two [latex]1[/latex] gallon buckets of liquid oxygen (the density of LOX (liquid oxygen) is [latex]1142[/latex] kg/m3, CRC Handbook of Chemistry and Physics.)
      • Write a balanced chemical equation describing this reaction.
      • Determine the limiting reagent for this reaction.
      • Calculate the mass of each product and any remaining reactant.
      • Calculate the amount of heat released by this reaction.
      • If this heat is used to warm a [latex]500[/latex] gallon tank of water at [latex]15^{\circ}[/latex]C, what is the final temperature?
      • If this heat is used to warm [latex]40[/latex] kg of ice at [latex]200^{\circ}[/latex]K, what is the final temperature?