Answer:
ΔH°rxn = -47 kJ
Explanation:
Using Hess´s law for the reaction:
3 Fe2O3(s) + CO(g) → 2 Fe3O4(s) + CO2(g) ,
the ΔH°rxn will be given by the expression:
ΔH°rxn kJ = 2ΔHºf(Fe3O4) + ΔHºf(CO2) - ( 3ΔHºf(Fe2O3) + ΔHºf(CO) )
= 2(-1118) + (-394) - ( 3( -824 ) + ( -111 ) )
= - 47 kJ
Answer:
The catalyzed reaction will take 2.85 seconds to occur.
Explanation:
The activation energy of a reaction is given by:

For the reaction without catalyst we have:
(1)
And for the reaction with the catalyst:
(2)
Assuming that frequency factor (A) and the temperature (T) are constant, by dividing equation (1) with equation (2) we have:

Since the reaction rate is related to the time as follow:
![k = \frac{\Delta [R]}{t}](https://tex.z-dn.net/?f=%20k%20%3D%20%5Cfrac%7B%5CDelta%20%5BR%5D%7D%7Bt%7D%20)
And assuming that the initial concentrations ([R]) are the same, we have:
![\frac{k_{1}}{k_{2}} = \frac{\Delta [R]/t_{1}}{\Delta [R]/t_{2}}](https://tex.z-dn.net/?f=%20%5Cfrac%7Bk_%7B1%7D%7D%7Bk_%7B2%7D%7D%20%3D%20%5Cfrac%7B%5CDelta%20%5BR%5D%2Ft_%7B1%7D%7D%7B%5CDelta%20%5BR%5D%2Ft_%7B2%7D%7D%20)


Therefore, the catalyzed reaction will take 2.85 seconds to occur.
I hope it helps you!
Answer:
1.76 g is the mass of Ne is in the container.
Explanation:
We use the equation given by ideal gas which follows:
where,
P = pressure of the gas = 650 mm Hg
V = Volume of the gas = 2.50 L
T = Temperature of the gas =
R = Gas constant =
n = number of moles of Ne gas = ?
Putting values in above equation, we get:

Also, molar mass of Ne = 20.1797 g/mol
So, 
<u>1.76 g is the mass of Ne is in the container.</u>
(i’m not very good at writing but use this as an idea)
changing the told would mess up the amount a daylight/nighttime because they’d be at a different angle from the sun
Answer:
positron
Explanation:
A positron is a particle produced when a proton is transformed into a neutron. Anti neutrinos are ejected from the nucleus to balance spins.
Positron emission increases the Neutron/Proton ratio. When a nuclide undergoes positron emission, the atomic number of the daughter nucleus is one unit less than that of the parent nucleus hence it is found one place before its parent in the periodic table.