Ask Question
25 June, 10:44

Using information in Appendices B and C in the textbook, calculate the minimum number of grams of propane, C3H8 (g), that must be combusted to provide the energy necessary to convert 6.15 kg of ice at - 16.5 ∘C to liquid water at 77.0 ∘C.

+2
Answers (1)
  1. 25 June, 14:11
    0
    The minimum number of grams of propane is 84.16 grams

    Explanation:

    The strategy here is to calculate first the amount of heat required to bring the ice at - 16.5 ºC to water at 77.0 ºC. After this we can calculate the minimum amount of propane which when combusted will give us the heat calculated in the first part.

    For the first part we need to know the specific heats of ice and water. The heat of melting will also be needed since the ice needs to be converted to liquid water (phase change).

    C (ice) : 2.108 kJ/KgK

    C (water) : 4.184 kJ/KgK

    Q to bring ice to 0ºC = mxC (ice) xΔT

    Q to 0ºC = 6.15 kg x 2.108 kJ/KgK x 16.5 K = 213.9 kJ

    Cmelting : 333.55 kJ/Kg

    Qmelting = Cmelting x mass

    Qmelting = 333.55 kJ/Kg * 6.15 Kg = 2051.33 kK

    Q to bring to 77 ºC = m x C (water) xΔT

    Q = 6.15 Kg x 4.184 kJ/KgK x (77 K) = 1981.33 kJ

    adding the heats calculated to bring the ice @-16.5 ºC to 77 ºC = (213.9+2051.33 + 1981.33) kJ

    = 4246.6 kJ

    Amount of Propane Required

    ΔH⁰combustion propane = - 2220 kJ/mol

    therefore for 4246.6kJ we will require

    4246.6 kJ x 1 mol/2220 kJ = 1.91 mol

    MW propane = 44 g/mol

    minimum mass of propane rqd = 1.91 mol x 44 g/mol = 84.2 g
Know the Answer?
Not Sure About the Answer?
Find an answer to your question ✅ “Using information in Appendices B and C in the textbook, calculate the minimum number of grams of propane, C3H8 (g), that must be combusted ...” in 📘 Chemistry if you're in doubt about the correctness of the answers or there's no answer, then try to use the smart search and find answers to the similar questions.
Search for Other Answers