Answer:
3.02x10²⁴
Explanation:
To solve this problem we need to use <em>Avogadro's number</em>: It is the number of units (usually atoms or molecules, in this case it's trucks) contained in one mol: 6.023x10²³.
We <u>multiply the given number of moles times Avogadro's number</u>:
5 * 6.023x10²³ = 3.02x10²⁴
So five moles of trucks would be 3.02x10²⁴ trucks.
Answer:
The word "Halloween" comes from All Hallows' Eve and means "hallowed evening."
Halloween's origins can be traced back to the ancient Celtic festival known as Samhain, which was held on November 1 in contemporary calendars. It was believed that on that day, the souls of the dead returned to their homes, so people dressed in costumes and lit bonfires to ward off spirits.
Explanation:
To solve this problem, we should recall that
the change in enthalpy is calculated by subtracting the total enthalpy of the reactants
from the total enthalpy of the products:
ΔH = Total H of products – Total H of reactants
You did not insert the table in this problem, therefore I
will find other sources to find for the enthalpies of each compound.
ΔHf CO2 (g) = -393.5 kJ/mol
ΔHf CO (g) = -110.5 kJ/mol
ΔHf Fe2O3 (s) = -822.1 kJ/mol
ΔHf Fe(s) = 0.0 kJ/mol
Since the given enthalpies are still in kJ/mol, we have to
multiply that with the number of moles in the formula. Therefore solving for ΔH:
ΔH = [<span>3 mol </span><span>( − </span><span>393.5 </span>kJ/mol<span>) + 1 mol (</span>0.0
kJ/mol)<span>] − [</span><span>3 mol </span><span>( − </span><span>110.5 </span>kJ/mol<span>) + </span><span>2 mol </span><span>( − </span><span>822.1 </span>kJ/mol<span>)]</span>
ΔH = <span>795.2
kJ</span>
Answer:
0.081g
Explanation:
first step:calculate the molar conc of the stock solution
molar conc=mass/molar mass ×1000/vol(ml)
molar mass of Co(N03)2=182.943
molar conc=3g/182.943 ×1000/100ml
=0.163M
To calculate the conc of the resulting solution we apply the dilution principle
n=cv
C1V1=C2V2
C1=conc of stock solution=0.163M
V1=4mL
V2=275ml(final volume)
by making 'C2" the subject C2=0.163×4/275
=0.0024M
by applying the formular for calculating molar conc of a solution,we can calculate the mass of CO(NO3)2 in the reulting solution
molar conc=mass/molar mass ×1000(L)/vol(mL)
mass=0.0024×182.943×275/1000
=0.1193g
Mass of CO(NO3)2 in the resulting solution=0.1199g
since CO+(NO3)2=CO(NO3)2
Percentage by mass of (NO3)2 in CO(NO3)2=(NO3)2/CO(NO3)2
=124/182.943×100
=67.8%
it means 67.8% of 0.1193g is the mass of (NO3)2=0.678×0.1199
=0.081g
<span>The radioactive uranium decays into its daughter product, lead. It would do this in magma as well, as nuclear decay depends on forces within the atom, not on the phase of the material in which the atom is a part.</span>