Answer:
4.09×10⁻³ is the mole fraction of sucrose
Explanation:
Mole fraction = Moles of solute or solvent/ Total moles
Let's convert the mass to moles (mass / molar mass)
38.6 g / 342 g/m = 0.113 moles of sucrose
495 g / 18 g/m = 27.5 moles of water
Total moles = 0.113 m + 27.5 m = 27.0613 moles
Mole fraction of sucrose = Moles of sucrose / Total moles
0.113 m / 27.0613 moles = 4.09×10⁻³
I would say D, because you need to start with nothing to measure the different sizes as they start to grow. hope this helps!
8.98
×
N
A
cobalt atoms
Explanation:
N
A
,
Avogadro's number
specifies
6.0221
×
10
23
individual particles. It is simply another collective number like a dozen, or a score, or a gross.
N
A
has the property that
6.0221
×
10
23
individual cobalt atoms has a mass of
58.93
⋅
g
. How did I know that? Did I have it memorized?
So the quantity is
≈
54
×
10
23
cobalt atoms.
This link might help you!!
https://www.eiu.edu/biology/bio1500/writing_a_lab_report.pdf