What is the solution's freezing point: 15 g of CH4N2O (Molar mass = 60.055 g/mol) in 200. g of H2O? (Kf = 1.86 (°C·kg)/mol)
1 answer:
Ok to answer this question we firsst need to fin the number of mol of Urea (CH4N2O). to do this we simply :
1 mol of urea =15/60.055 = 0.25mol
therefore 200g of water contain 0.25mol
the next step is to determine the malality of our solution in 200g of water, to do this we say:
200 g = 1Kg/1000g = 0.2kg
therefor 0.25mol/0.2Kg = 1.25mol/kg
and from the equation:
we know that i = 1
we are given Kf
b is the molality that we just calculated
therefore;
the solutions freezing point is -2.325°C
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Answer:
The correct answer is: 1.316 . 10⁻³ m³/kg.
Explanation:
The density (ρ) of a substance is the ratio of its <em>mass (m)</em> to its <em>volume (V)</em>. At constant temperature and pressure, its value is constant and it is an intrinsic property of materials. The units of density are kg/m³.
The specific volume (ν) of a substance is the ratio of its <em>mass</em> to its <em>volume</em>. We can see that it is the reciprocal of density and an intrinsic property of matter as well. Therefore, the units of specific volume are m³/kg.
Given we know the density of the liquid, we can use this relationship to find out its specific volume: