1) 
Moles of methanol = 
Mass of
that would produce 208 kg methanol =

2) Mass of sodium = 
3) Mass of mercury = 
Number of atoms of mercury = 
Answer:
Explanation:
We're asked to calculate the number of atoms of
Ca
in
153
g Ca
.
What we must first do is convert the given mass of calcium to moles of calcium, using its molar mass (referring to a periodic table, this is
40.08
g
mol
):
153
g Ca
(
1
mol Ca
40.08
g Ca
)
=
3.82
mol Ca
Using Avogadro's number,
6.022
×
10
23
particles
mol
, we can calculate the number of atoms present:
3.82
mol Ca
(
6.022
×
10
23
atoms Ca
1
mol Ca
)
=
2.30
×
10
24
atoms Ca
Answer:
18.0 Ampere is the size of electric current that must flow.
Explanation:
Moles of electron , n = 550 mmol = 0.550 mol
1 mmol = 0.001 mol
Number of electrons = N

Charge on N electrons : Q

Duration of time charge allowed to pass = T = 49.0 min = 49.0 × 60 seconds
1 min = 60 seconds
Size of current : I



18.0 Ampere is the size of electric current that must flow.