A first-year student did a calorimetry experiment to determine the heat capacity ofethylene glycol (C 2 H 6 O 2 ). They mixed 55 g of water at 83.6 o C with 120 g of ethyleneglycol at 17.9 o C in a well-insulated polystyrene container of negligible heat capacity.After stirring, they measured the temperature of the mixture to be 47.1 o C.Calculate the specific heat capacity of ethylene glycol.(The specific heat capacity of water is 4.184 J g -1 K -1 )
Question
A first-year student did a calorimetry experiment to determine the heat capacity ofethylene glycol (C 2 H 6 O 2 ). They mixed 55 g of water at 83.6 o C with 120 g of ethyleneglycol at 17.9 o C in a well-insulated polystyrene container of negligible heat capacity.After stirring, they measured the temperature of the mixture to be 47.1 o C.Calculate the specific heat capacity of ethylene glycol.(The specific heat capacity of water is 4.184 J g -1 K -1 )
Solution
To solve this problem, we can use the principle of conservation of energy, which states that the heat lost by the hot substance (water) is equal to the heat gained by the cold substance (ethylene glycol).
The formula for heat transfer is Q = mcΔT, where Q is the heat transferred, m is the mass, c is the specific heat capacity, and ΔT is the change in temperature.
First, we calculate the heat lost by the water:
Q_water = m_water * c_water * ΔT_water Q_water = 55 g * 4.184 J/g°C * (83.6°C - 47.1°C) Q_water = 55 g * 4.184 J/g°C * 36.5°C Q_water = 8393.42 J
Next, we calculate the heat gained by the ethylene glycol. We don't know the specific heat capacity of ethylene glycol (c_glycol), so we'll leave it as a variable:
Q_glycol = m_glycol * c_glycol * ΔT_glycol Q_glycol = 120 g * c_glycol * (47.1°C - 17.9°C) Q_glycol = 120 g * c_glycol * 29.2°C
Since the heat lost by the water is equal to the heat gained by the ethylene glycol, we can set the two equations equal to each other and solve for c_glycol:
8393.42 J = 120 g * c_glycol * 29.2°C c_glycol = 8393.42 J / (120 g * 29.2°C) c_glycol = 2.39 J/g°C
So, the specific heat capacity of ethylene glycol is approximately 2.39 J/g°C.
Similar Questions
Ethylene glycol has a specific heat of 0.578 cal/(g•°C). If the temperature of a 23.2 g sample of ethylene glycol is raised from 10.00 °C to 15.64 °C, how much heat energy is absorbed by the sample?
A 59.0g sample of polystyrene is put into a calorimeter (see sketch at right) that contains 300.0g of water. The polystyrene sample starts off at 86.5°C and the temperature of the water starts off at 20.0°C. When the temperature of the water stops changing it's 24.1°C. The pressure remains constant at 1atm.Calculate the specific heat capacity of polystyrene according to this experiment. Be sure your answer is rounded to the correct number of significant digits.
A coolant solution is prepared using 250.0 mL of propylene glycol C3H8O2 with density 1.04g/cc, in 300.0 g of water. Calculate the new boiling point of the water. Note: Kb = 0.512degrees Celsius/molal
A chemist carefully measures the amount of heat needed to raise the temperature of a 832.0g sample of a pure substance from 26.3°C to 37.4°C. The experiment shows that 17.1kJ of heat are needed. What can the chemist report for the specific heat capacity of the substance? Round your answer to 3 significant digits.
A chemist mixes 75.0 g of an unknown substance at 96.5°C with 1,150 g of water at 25.0°C. If the final temperature of the system is 37.1°C, what is the specific heat capacity of the substance? Use 4.184 J / g °C for the specific heat capacity of water. A. 368 J / g °C B. 13.1 J / g °C C. 0.368 J / g °C D. 0.0112 J / g °C
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.