Susan should follow PEMDAS,
Parentheses
Exponents
Multiplication
Division
Addition
Subtraction,
So, the first step should be, to solve the equation in the parentheses.
I hope this helps!
Answer:
Isotopes are atoms of the same element that have different numbers of neutrons but the same number of protons and electrons. The difference in the number of neutrons between the various isotopes of an element means that the various isotopes have different masses.
Answer:
The reactions free energy 
Explanation:
From the question we are told that
The pressure of (NO) is 
The pressure of (Cl) gas is 
The pressure of nitrosly chloride (NOCl) is 
The reaction is
⇆ 
From the reaction we can mathematically evaluate the
(Standard state free energy ) as

The Standard state free energy for NO is constant with a value

The Standard state free energy for
is constant with a value

The Standard state free energy for
is constant with a value

Now substituting this into the equation

The pressure constant is evaluated as

Substituting values


The free energy for this reaction is evaluated as

Where R is gas constant with a value of 
T is temperature in K with a given value of 
Substituting value
![\Delta G = -43 *10^{3} + 8.314 *298 * ln [0.0765]](https://tex.z-dn.net/?f=%5CDelta%20%20G%20%20%3D%20-43%20%2A10%5E%7B3%7D%20%2B%208.314%20%2A298%20%2A%20ln%20%5B0.0765%5D)

