Answer:
1.204 × 10^24 formula units
Explanation:
Using the following formula to convert mass of iron (III) chloride to moles;
mole = mass/molar mass
Molar mass of FeCl3 = 56 + 35.5(3)
= 56 + 106.5
= 162.5g/mol
Mole = 325/162.5
mole = 2mol
Next, to calculate the formula units of FeCl3, we multiply the number of moles of FeCl3 by Avagadro number (6.02 × 10^23)
Formula units of FeCl3 = 2 × 6.02 × 10^23
12.04 × 10^23
= 1.204 × 10^24 formula units.
Answer:
a) 381.2 g
b) 39916 g
c) 0.0013 lb mol
d) 29.6 g mol
Explanation:
The molecular weight (mw) of a compound is the mass of it per mole, so it's the ratio of the mass (m) per mole (n).
a) The molecular weight of one mol is found at the periodic table. So, for Mg, mw = 24.3 g/mol, for Cl = 35.5 g/mol, so for MgCl2, mw = 24.3 + 2*35.5 = 95.3 g/mol. The g mol is the mass divided by the molecular weight:
g mol = m/mw
4 = m/95.3
m = 381.2 g
b) The pound (lb) is a unity of mass, and the lb mol is a unity of the mass divided by the molecular weight. So, by the periodic table, the molecular weight of C3H8 is 3*12 (of C) + 8*1 (of H) = 44 lb/mol.
lb mol = m/mw
2 = m/44
m = 88 lb
1 lb = 453.592 g
So, m = 88*453.592 = 39916 g
c) The molecular weight of N2 is 2*14 (of N) = 28 lb/mol.
m = 16/453.592 = 0.0353 lb
lb mol = m/mw
lb mol = 0.0353/28
lb mol = 0.0013 lb mol
d) The molecular weight is 2*12 (of C) + 6*1(of H) + 1*16(of O) = 46 g/mol
3 lb = 1360.78 g
g mol = m/mw
g mol = 1360.78/46
g mol = 29.6 g mol
A model is a purposeful representation of reality. When law is more complex and dynamic. Law is the description of an observed phenomenon. Make sense?
Hopefully that helped :)
