The melting point (or, rarely, liquefaction point) of a solid is the temperature at which it changes state from solid to liquid at atmospheric pressure. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at standard pressure.
We can find the principal level or lower level
using Rydberg's formula:
1/w = R(1/L² - 1/U²)
<span>where:</span>
<span>w is the
wavelength (93.8 nm),</span>
L is the lower energy level (unknown)
U the upper energy level (n= 6)
R is Rydberg's constant (10,967,758
waves per meter)
Substituing known values into the equation:<span>
1/(9.38 * 10^-8 m.) = 10,967,758(1/L² - 1-36) </span>
Using the solver function of the calculator to
get for L:
L = 0.999 <span>
so L = 1.
<span>The lower level is 1 (the ground state).</span></span>
<span>1.4 moles of aluminium metal is exposed to 1.35 mol of oxygen
Theoretical yield=0.007 mol
calculate % yield
% yield= actual yield/theoretical yield*100
% yield= 0.938/0.700*100
% yield= 13.4% yield</span>
Answer:
a. ΔH⁸ = -1420 kJ/mol b. ΔH⁸ = -1144.84 kJ/mol
Explanation:
a.
C₂H₄ (g) + 3 O₂ (g) ------------------------ 4 CO₂ (g) + 2 H₂O (l) ΔH⁸ = ?
ΔH⁸f kJmol 52.47 0 -399.5 -285.83
ΔH⁸ = 2(-399.5) + 2 (-285.83) - (52.47)
ΔH⁸ = -1420 kJ/mol
b.
H₂S (g) + 3 O₂ (g) ---------------------- 2 H₂O (l) + 2 SO₂ (g)
ΔH⁸f kJmol -20.50 0 -285.83 -296.84
ΔH⁸ = 2(-285.83) + 2 (-296.84) - (-20.50)
ΔH⁸ = -1144.84 kJ/mol
