I think the best answer from the choices is option B. <span>Atmospheric chemists think that Earth’s first atmosphere contained no oxygen atoms. It was believed that the early atmosphere of the Earth was due to the volcanic activities which are not known to produce oxygen atoms. Therefore, chemists think that there were no atoms of oxygen.</span>
Answer:
m = 3 moles/kg
Explanation:
This is a problem of freezing point depression, and the formula or expression to use is the following:
ΔT = i*Kf¨*m (1)
Where:
ΔT: Change of temperature of the solution
i: Van't Hoff factor
m: molality of solution
Kf: molal freezing point depression of water (Kf = 1.86 °C kg/mol)
Now, the value of i is the number of moles of particles obtained when 1 mol of a solute dissolves. In this case, we do not know what kind of solution is, so, we can assume this is a non electrolyte solute, and the value of i = 1.
Let's calculate the value m, which is the molality solving for (1):
m = ΔT/Kf (2)
Finally, let's calculate ΔT:
ΔT = T2 - T1
ΔT = 0 - (-5.58)
ΔT = 5.58 °C
Now, let's replace in (2):
m = 5.58/1.86
<em>m = 3 moles/kg</em>
<em>This is the molality of solution.</em>
<em>The other data of mass, can be used to calculate the molecular mass of this unknown solid, but it's not asked in the question.</em>
Oil being less dense than water floats on it. Had it been denser than water like iron, it would have sunk. Density is mass per unit volume. It means that if you take a cubic cm (cc) of oil, its mass is much lesser than a cubic cm of water.
Hope this helped
Good luck
Brainliest is appreciated
~ Emmy