Answer:
177.8kJ/mol
Explanation:
In this reaction, the heat of decomposition is the same as the heat of formation. This is a decomposition reaction.
Given parameters:
ΔHf CaCO₃ = -1206.9kJ/mol
ΔHf CaO = −635.6 kJ/mol
ΔHf CO₂ = −393.5 kJ/mol
The heat of decomposition =
Sum of ΔHf of products - Sum of ΔHf of reactants
The equation of the reaction is shown below:
CaCO₃ → CaO + CO₂
The heat of decomposition = [ -635.6 + (-393.5)] - [−1206.9 ]
= -1029.1 + 1206.9
= 177.8kJ/mol
Answer:
Explanation:
Ionization energy of hydrogen atom is 13.6 eV . This energy will be provided by energetic proton , the kinetic energy of which is 1000 eV. The kinetic energy of ionized electron is 15.2 eV . Kinetic energy of proton produced from from the ionization of hydrogen or the nucleus of the hydrogen atom is 4.3 eV . All these energy must have come from kinetic energy of initial proton.
So kinetic energy of projectile proton after collision
= 1000 - ( 13.6 + 15.2 + 4.3 ) eV.
= 966.9 eV .
For the purpose we will here use t<span>he ideal gas law:
p</span>×V=n×R×<span>T
V= </span><span>5.0 L
T= </span><span>373K
p= </span><span>203kPa
</span><span>
R is </span> universal gas constant, and its value is 8.314 J/mol×<span>K
</span>
Now when we have all necessary date we can calculate the number of moles:
n=p×V/R×T
n= 203 x 5 / 8.314 x 373 = 0.33 mole
solution:
the change in the boiling point is given as,
dTbp =2.30°c
elevation constant for the solvent is given by,
kb=0.512°c/m
= 4.49m
To solve this problem, we assume ideal gas so that we can
use the formula:
PV = nRT
since the volume of the flask is constant and R is
universal gas constant, so we can say:
n1 T1 / P1 = n2 T2 / P2
1.9 mol * (21 + 273 K) / 697 mm Hg = n2 * (26 + 273 K) /
841 mm Hg
<span>n2 = 2.25 moles</span>
