Answer is: 60.
In one molecule of C₂₀H₄₂S₃O₂, there is 2 atoms of oxygen (subscript after oxygen indicates number of atoms of oxygen in chemical (molecular) formula).
So, in 30 molecules of C₂₀H₄₂S₃O₂, there is: 30·2 = 60 atoms of oxygen.
Answer:
Chemical energies
Explanation:
We get chemical energy from foods, which we use to run about, and move and talk (kinetic and sound energy). Chemical energies are stored in fuels which we burn to release thermal energy - this is one way of making electricity, see Electricity for more information.
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:
we use atom in our sentences all the time
Explanation:
that what i put
