Answer:
- A. Which element, X or Z, has a higher molar mass?
Explanation:
Heating the original compounds intensely to remove all oxygen causes chemical decomposition reactions:
- 2XClO₃ (solid) → 2XCl + 3O₂ (gas)
- 2ZClO₃ (solid) → 2ZCl + 3O₂ (gas)
By measuring the initial mass of each sample and the mass remaining after heating, the student can compute the oxygen gas mass released:
- Mass of oxygen released = initial sample mass minus residue mass
Using this oxygen mass, she can calculate how many moles of oxygen were present in each sample:
- Moles of oxygen = oxygen mass (g) divided by molar mass of oxygen
Next, the moles of the original sample are determined:
- Each mole of XClO₃ or ZClO₃ has 3 moles of oxygen atoms.
So, dividing the moles of oxygen released by 3 gives the moles of the sample.
Applying the formula molar mass = mass / moles, the student finds the molar masses of XClO₃ and ZClO₃.
Thus, this data allows answering question A: Which of X or Z has the higher molar mass?
Response:
The cuvette was prepared with the solution so that the spectrometer measures solely the absorbance from the solute. This also means the spectrometer disregards other fluctuations in absorbance that typically arise from the composition of water. The spectrometer focused only on the absorbance of 
as reflected in the spectrum. The reaction between the 
and the 
produces two clear liquids that generate the orange product which leads to the absorbance spectrum. Due to the orange color of the solution, it reflects this hue and others like it, while absorbing blue tones. To isolate the absorption of just the , pre-rinsing the cuvette with the solutions intended for measurement is advisable, along with using a kimwipe to clean any fingerprints that might impact data collection.
Clarification:
The cuvette was prepared with the solution so that the spectrometer measures solely the absorbance from the solute. This also means the spectrometer disregards other fluctuations in absorbance that typically arise from the composition of water. The spectrometer focused only on the absorbance of as reflected in the spectrum.
