Answer:
Explanation:
The octet rule does not always refer to a stable arrangement of eight valence electrons because there are some element that do not have eight valence electrons yet they are stable. for example;
i) Helium, It has two valence electrons and it is a stable gas.
ii) Boron triflouride (BF3); it has six valence electrons (deficit valence electron) yet it is also stable.
iii) Phosphorus pentachloride (PCl5); it has more than eight valence electron and it is also stable.
For these few reasons it is not always advisable to say octet arrangement refer to stable eight valence electrons.
<h2>Ultraviolet Light</h2>
Explanation:
- The energy of a photon that will be released if an electron falls from the n= 2 orbit (excited state) to the n0 = 1 orbit (ground state) is of ultraviolet light.
- In the ultraviolet part of the spectrum, a photon having an energy of 10.2 eV has a wavelength of 1.21 x 10-7 m.
- Hence, when an electron wants to jump or it gets excited from the first level to the second level that is from n = 1 orbit to n = 2 orbits, it must absorb a photon of ultraviolet light.
- But,When an electron falls from n = 2 orbit to n = 1 orbit or from n = 2 orbit(excited state) to n = 0 orbit(groubd state), it emits a photon of ultraviolet light.
To solve this we assume that the hydrogen gas is an
ideal gas. Then, we can use the ideal gas equation which is expressed as PV =
nRT. At a constant pressure and number of moles of the gas the ratio T/V is
equal to some constant. At another set of condition of temperature, the
constant is still the same. Calculations are as follows:
T1 / V1 = T2 / V2
V2 = T2 x V1 / T1
V2 = (100 + 273.15) K x 2.50 L / (-196 + 273.15) K
<span>V2 = 12.09 L</span>
Therefore, the volume would increase to 12.09 L as the temperature is increased to 100 degrees Celsius.
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Recall; pH + pOH = 14
In this case [OH-] =0.100 m
therefore;
pOH = -LOG[OH-]
= - Log (0.100)
= 1.00
Therefore; the pOH is 1.00
And since, pH +pOH = 14
Then pH = 14-pOH
= 14 -1
= 13
Thus the pH is 13.00
