Based on the equation:
ΔG = ΔH - TΔS = 0
It follows that ΔS = ΔH/T
So, ΔS = n*ΔHVap / Tvap
- where n represents the number of moles calculated as mass/molar mass
For a mass of 24.1 g
and a molar mass of 187.3764 g/mol
substituting gives:
∴ n = 24.1 / 187.3764g/mol
= 0.129 moles
The molar enthalpy of vaporization, ΔHvap, is 27.49 kJ/mol
The temperature in Kelvin, Tvap = 47.6 + 273 = 320.6 K
After substitution, we compute ΔS, the change in entropy:
∴ΔS = 0.129 mol * 27490 J/mol / 320.6 K
= 11 J/K
Answer:
The specific gravity of the saturated solution is 2
Explanation:
Specific gravity represents the ratio of the density of a solution, in this case, a saturated potassium iodide (KI) solution, to the density of water. Assuming the density of water is 1:
Specific gravity = Density
Density itself is defined as the mass divided by volume.
In 100mL of water, the mass of dissolve-able KI is:
100mL * (1g KI / 0.7mL) = 143g of KI
This indicates that all 100g of KI dissolves (Mass solute)
With 100mL of water corresponding to a mass of 100g (Mass solvent)
The overall mass of the solution computes to 100g + 100g = 200g
In a volume of 100mL, the solution's density is:
200g / 100mL = 2g/mL.
Specific gravity is a dimensionless quantity, thus the specific gravity of the saturated solution is 2
The amount of oxygen atoms present is approximately 3.27·10²³. To determine this figure, we must first assess the sodium sulfate sample. The chemical formula for it is Na₂SO₄, which possesses a molar mass of roughly 142.05 g/mol. We can then use stoichiometry to convert the mass of Na₂SO₄ into moles. By knowing the moles of Na₂SO₄, we will subsequently convert this to moles of oxygen utilizing the mole ratio and finally apply Avogadro's number to convert to atoms of oxygen. Thus, with the calculations completed, the resulting quantity of oxygen atoms is about 3.27·10²³.
To determine the mass of AlF3 in 2.64 moles of AlF3, we use the formula: mass = moles x molar mass, which results in 221.76 grams of AlF3.
