I can t figure out this chemistry problem:
Camphor, (C10H16)) has a heat of combustion of 5903.6kJ/mole. A sample of camphor with a mass of 0.1204 g is burned in a bomb calorimeter. The temperature increases by 2.28 degrees Celsius. What is the heat capacity of the calorimeter?
I need help with a chemistry problem.?
2017-11-01 9:00 am
回答 (2)
2017-11-01 9:30 am
Molar mass of C₁₀H₁₆ = (12.01×10 + 1.008×16) g/mol = 136.23 g/mol
No. of moles of C₁₀H₁₆ burned = (0.1204 g) / (136.23 g/mol) = 0.0008838 mol
Heat released in burning C₁₀H₁₆ = (5903.6 × 1000 J/mol) × (0.0008838 mol) = 5217.6 J
Heat absorbed by the calorimeter = m c ΔT = 2.28mc J
Heat absorbed by the calorimeter = Heat released in burning C₁₀H₁₆
2.28mc = 5217.6
Heat capacity of the calorimeter, mc = 2290 J/°C (to 3 sig. fig.)
No. of moles of C₁₀H₁₆ burned = (0.1204 g) / (136.23 g/mol) = 0.0008838 mol
Heat released in burning C₁₀H₁₆ = (5903.6 × 1000 J/mol) × (0.0008838 mol) = 5217.6 J
Heat absorbed by the calorimeter = m c ΔT = 2.28mc J
Heat absorbed by the calorimeter = Heat released in burning C₁₀H₁₆
2.28mc = 5217.6
Heat capacity of the calorimeter, mc = 2290 J/°C (to 3 sig. fig.)
2017-11-01 9:32 am
Mass of one mole = 12 * 10 + 16 = 136 grams
n = 0.1204 ÷ 136
This is approximately 8.45 * 10^-4 mole. To determine the amount of heat energy that is used to increase the temperature, multiply the heat of combustion in J/mole by the number of moles.
Q = 5903.6 * 1000 * 0.1204 ÷ 136 = 710,793.44 ÷136
This is approximately 5,226 J. Let’s use the following equation to determine the heat capacity of the camphor.
Q = mass * heat capacity * ∆ T
710,793.44 ÷136 = x * 2.28
x = 710,793.44 ÷ 310.08
The heat capacity is approximately 2287 J(g * ˚C).
n = 0.1204 ÷ 136
This is approximately 8.45 * 10^-4 mole. To determine the amount of heat energy that is used to increase the temperature, multiply the heat of combustion in J/mole by the number of moles.
Q = 5903.6 * 1000 * 0.1204 ÷ 136 = 710,793.44 ÷136
This is approximately 5,226 J. Let’s use the following equation to determine the heat capacity of the camphor.
Q = mass * heat capacity * ∆ T
710,793.44 ÷136 = x * 2.28
x = 710,793.44 ÷ 310.08
The heat capacity is approximately 2287 J(g * ˚C).
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