Answer:
-65.897°C.
Explanation:
- Adding solute to water causes depression of the boiling point.
- The depression in freezing point (ΔTf) can be calculated using the relation: <em>ΔTf = Kf.m,</em>
where, ΔTf is the depression in freezing point of chloroform solution.
Kf is the molal depression constant of chloroform (Kf = 4.70°C.kg/mol).
m is the molality of the solution (m = 0.51 m).
∴ ΔTf = Kf.m = (4.70°C.kg/mol)(0.51 m) = 2.397°C.
∴ The freezing point of the solution = (freezing point of chloroform) - ΔTf = (-63.5°C) - (2.397°C) = -65.897°C.
This is because, only <span> weak van der Waals forces or weak London dispersion forces are present between the atoms of the </span><span>noble gases.
Hope this helps!</span>
B. 347 m/s
My friend and I did an experiment to find the speed of sound and we came very close to the actual value.
Answer:
83.24 mmHg.
Explanation:
- <em>The vapor pressure of the solution (Psolution) = (Xmethanol)(P°methanol).</em>
where, Psolution is the vapor pressure of the solution,
Xmethanol is the mole fraction of methanol,
P°methanol is the pure vapor pressure of methanol.
- We need to calculate the mole fraction of methanol (Xmethanol).
<em>Xmethanol = (n)methanol/(n) total.</em>
where, n methanol is the no. of moles of methanol.
n total is the total no. of moles of methanol and urea.
- We can calculate the no. of moles of both methanol and urea using the relation: n = mass/molar mass.
n of methanol = mass/molar mass = (56.9 g)/(32.04 g/mol) = 1.776 mol.
n of urea = mass/molar mass = (7.38 g )/(60.06 g/mol) = 0.123 mol.
∴ Xmethanol = (n)methanol/(n) total = (1.776 mol)/(1.776 mol + 0.123 mol) = 0.935.
<em>∴ Psolution = (Xmethanol)(P°methanol)</em> = (0.935)(89.0 mmHg) =<em> 83.24 mmHg.</em>
If the pressure on an ideal gas is increased, the volume of the gas will decrease. This can be predicted with the use of the ideal gas equation which is expressed as: PV = nRT. At constant temperature, we can say that pressure and volume are inversely related. Thus, as one value increase, the other decrease.