The visible constellations<span> are definitely different
between the Northern and Southern Hemispheres. In general, at any given point
on Earth, only around 50% of the sky will be visible. We can understand this by
considering the atmosphere as a sphere around the earth. The sky any person can
view at one point can be compared to a giant dome equal to half of the sphere.
And because the Earth rotates, the dome we can see changes, unless one is
sitting directly on the North or South Pole.</span>
<span>One mol of NaCl (6.02 x1023 formulas) has a mass of 58.44 g. Concept 2. The relation between molecular (formula) mass and molar mass. To obtain one mole of copper atoms (6.02 x 1023 atoms), weigh out 63.55 g copper.</span>
Explanation:
The given data is as follows.
Pressure (P) = 170 torr, mass of heptane (m) = 86.7 g
First, we will calculate the number of moles as follows.
No. of moles = 
= 
= 0.867 mol
Now, the number of moles of
are calculated as follows.
No. of moles = 
=
= 1.07
Therefore, mole fraction of heptane will be calculated as follows.
Mole fraction =
= 
= 
= 0.445
Now, we will calculate the partial pressure of heptane as follows.

=
= 75.65 torr
Thus, we can conclude that the partial pressure of heptane vapor above this solution is 75.65 torr.