<u>Answer:</u>
<u>For A:</u> The
for the given reaction is 
<u>For B:</u> The
for the given reaction is 1642.
<u>Explanation:</u>
The given chemical reaction follows:

The expression of
for the above reaction follows:

We are given:

Putting values in above equation, we get:

Hence, the
for the given reaction is 
Relation of
with
is given by the formula:

where,
= equilibrium constant in terms of partial pressure = 
= equilibrium constant in terms of concentration = ?
R = Gas constant = 
T = temperature = 500 K
= change in number of moles of gas particles = 
Putting values in above equation, we get:

Hence, the
for the given reaction is 1642.
<u>Answer: </u>The correct statement is X is the effective nuclear charge, and it increases across a period.
<u>Explanation:</u>
We are given that:
X = number of protons − number of core electrons
Effective nuclear charge is defined as the actual nuclear charge (Z = number of protons) minus the screening effect caused by the electrons present between nucleus and valence electrons. These electrons are the core electrons.
The formula used for the calculation of effective nuclear charge given by Slater is:

where,
= effective nuclear charge
Z = atomic number or actual nuclear charge or number of protons
= Screening constant
The effective nuclear charge increases as we go from left to right in a period because nuclear charge increases with no effective increase in screening constant.
Hence, the correct answer is X is the effective nuclear charge, and it increases across a period.
The dense aerosol cloud created caused decreases in the amount of solar radiation that reached the Earths surface.
2H2O=2H2+O2
37.4g H2O(1 mol/18.02)=2.07547 mol H2O
PV=nRT
(1.30)(V)=(2.07547)(.0821)(297)
Vwater=38.92898L
38.92898L (1 mol O2/2 mol H2O)=19.46449L O2 gas