D) Distillation is the process used to separate a solid from a liquid through <span>evaporating the liquid..</span>
<u>Answer:</u> The
of the reaction at given temperature is -12.964 kJ/mol.
<u>Explanation:</u>
For the given chemical reaction:

The expression of
for the given reaction:

We are given:

Putting values in above equation, we get:

To calculate the Gibbs free energy of the reaction, we use the equation:

where,
= Gibbs' free energy of the reaction = ?
= Standard gibbs' free energy change of the reaction = 0 J (at equilibrium)
R = Gas constant = 
T = Temperature = ![25^oC=[25+273]K=298K](https://tex.z-dn.net/?f=25%5EoC%3D%5B25%2B273%5DK%3D298K)
= equilibrium constant in terms of partial pressure = 
Putting values in above equation, we get:

Hence, the
of the reaction at given temperature is -12.964 kJ/mol.
Answer:
0.5188 M or 0.5188 mol/L
Explanation:
Concentration is calculated as <u>molarity</u>, which is the number of moles per litre.
***Molarity is represented by either "M" or "c" depending on your teacher. I will use "c".
The formula for molarity is:
n = moles (unit mol)
V = volume (unit L)
<u>Find the molar mass (M) of potassium hydroxide.</u>

<u>Calculate the moles of potassium hydroxide.</u>


Carry one insignificant figure (shown in brackets).
<u>Convert the volume of water to litres.</u>


Here, carrying an insignificant figure doesn't change the value.
<u>Calculate the concentration.</u>

<= Keep an insignificant figure for rounding
<= Rounded up
<= You use the unit "M" instead of "mol/L"
The concentration of this standard solution is 0.5188 M.