Hi there! Calvin informed Marie that they could still incorporate solute until reaching 40 grams because the solution remained unsaturated. Unsaturated solutions denote situations where the solvent (water in this instance) can further dissolve more solute (here, KNO₃) considering the current pressure and temperature. This can be visually confirmed when additional solute does not lead to visible solid residues settling at the bottom of the flask, indicating that the dissolving rate surpasses the crystallization rate. Wishing you a pleasant day!
I predict that there will be an increase in the seconds recorded in the time column. This is because, as more water is mixed with sodium thiosulfate, its concentration diminishes in each flask. Additionally, a lower concentration results in a slower reaction rate since fewer molecules of sodium thiosulfate means there are less frequent collisions with sulfuric acid. With fewer collisions occurring in the reaction, it takes a longer time for the reaction to complete, leading to increased time when sodium thiosulfate is diluted.
Explanation:
I can confirm that this explanation is accurate.
Response:
To reach the answer, 465.6 mg of MgI₂ is required.
Detailed Explanation:
We need to establish the moles of ion I⁻ in the resulting solution.
C = n/V -> n = C x V = 0.2577 (L) x 0.1 (mol/L) = 0.02577 mol.
In the initial solution, there was 0.087 M KI, which we can similarly convert into moles, yielding 0.02242 mol.
This indicates we require an additional amount of 0.02577 - 0.02242 = 0.00335 mol of I⁻. Since each molecule of MgI₂ produces two I⁻ ions, we divide 0.00335 by 2 to determine the moles of MgI₂, giving us 0.001675 mol.
Consequently, the quantity of MgI₂ to be added is:
Weight of MgI₂ = 0.001675 mol x 278 g/mol = 0.4656 g = 465.6 mg
