In the calorimeter (calibration factor, CF), n mol of butane was then burnt and the resulting temperature rise (ΔT) was measured - VCE - SSCE Chemistry - Question 19 - 2007 - Paper 1
Question 19
In the calorimeter (calibration factor, CF), n mol of butane was then burnt and the resulting temperature rise (ΔT) was measured.
The ΔH, in 1 mol<sup>-1</sup>, for ... show full transcript
Worked Solution & Example Answer:In the calorimeter (calibration factor, CF), n mol of butane was then burnt and the resulting temperature rise (ΔT) was measured - VCE - SSCE Chemistry - Question 19 - 2007 - Paper 1
Step 1
A. 2 × CF × ΔT × n
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
This expression suggests that the change in enthalpy (ΔH) is calculated by multiplying the calibration factor (CF), the temperature rise (ΔT), and the number of moles (n) involved in the reaction. While this is relevant, it isn't the final ratio needed for ΔH per mole.
Step 2
B. \( \frac{2 \text{ CF}}{n} \)
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
This formula indicates that the calibration factor is being divided by the number of moles (n) with a coefficient of 2. Since the reaction consumes 2 moles of butane, this option correctly translates the total energy change for the reaction into an energy change per mole of butane, making this response correct.
Step 3
C. \( \frac{CF}{2} \)
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
This option divides the calibration factor by 2 but does not account for the total quantity of n moles burned. Thus, it does not correctly represent the change in enthalpy per mole.
Step 4
D. \( \frac{CF}{n} \)
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
This expression divides the calibration factor by the total moles. While indicative of a proportional relationship, it lacks the necessary factor accounting for the stoichiometry of the reaction, making it incorrect.
