Phthalates used as plasticizers in rubber and plastic products are believed to act as hormone mimics in human. The value of deltaHcombustion for dimethylphthalate (C10H10O4) is 4685 kJ/mol. Assume 1.035 g of dimethylphthalate is combusted in a calorimeter whose heat capacity (C calorimeter) is 7.293 kJ/Celsius at 20.142 Celsius. What is the final temperature of the calorimeter?
4685 kJ/mol x (1.035g/molar mass) = ? and convert to J.
q joules = Ccal x (Tfinal-Tinitial)
Solve for Tf. I would put Ccal in J.
How do you convert 4848.975 to J?
kJ x 1000 = J.
But where did you get 4868.97...?
4685 x (1.035/197...) isn't anywhere near that number. I think you did not divide by the molar mass of the phthalate.
Ok, yeah I somehow read that as a label not as part of the equation, so
4685*(1.035/194.21)= 24.97
24.97*1000=24967.69
So then would the final equation be:
24967.69=7.293(Tfinal-20.142)
Thank you by the way Im just really struggling with this.
Yes except you need to convert that 7.293 kJ to J.
To find the final temperature of the calorimeter, you can use the concept of heat transfer and the equation for heat capacity. The heat released by the combustion of dimethylphthalate will be transferred to the calorimeter and raise its temperature. Here's how you can calculate it:
1. Calculate the heat released by the combustion of dimethylphthalate:
- The molar mass of dimethylphthalate (C10H10O4) = 194.18 g/mol.
- The moles of dimethylphthalate combusted = mass / molar mass
-> moles = 1.035 g / 194.18 g/mol = 0.00533 mol.
- The heat released = moles of dimethylphthalate combusted × ΔHcombustion
-> heat released = 0.00533 mol × 4685 kJ/mol = 24.96 kJ.
2. Calculate the temperature change of the calorimeter using the equation:
- Heat released = Ccalorimeter × ΔT
-> 24.96 kJ = 7.293 kJ/Celsius × ΔT
-> ΔT = 24.96 kJ / 7.293 kJ/Celsius
-> ΔT = 3.424 Celsius.
3. Determine the final temperature of the calorimeter:
- The initial temperature of the calorimeter is 20.142 Celsius.
- The final temperature = initial temperature + ΔT
-> final temperature = 20.142 Celsius + 3.424 Celsius
-> final temperature = 23.566 Celsius.
Therefore, the final temperature of the calorimeter is approximately 23.566 Celsius.