Answer:
One mole is the Avogadro's number of particles (atoms, molecules, ions or electrons) in a substance. Converting to moles is fairly easy because the conversion is always the same.
<span>Neutrons.
The nucleus of an atom contains two kinds of particles, protons and neutrons. The number of protons determines what element the atom is. Atoms that have the same number of protons but different numbers of neutrons are isotopes of the same element.
For example, if two atoms both have 1 proton in their nuclei, but one atom has 0 neutrons and the other has 1 neutron, both atoms are hydrogen but they are different isotopes of hydrogen.</span>
Explanation:
We leave a soda in the car overnight and the temperature dips to 25 °F. To see if it will freeze we have to convert the °F to °C.
T(°C) = ( T(°F) - 32 ) *5/9
T(°C) = (25 - 32) *5/9
T(°C) = -3.9 °C
Since -3.9 °C is a temperature greater than the freezing point (-4.5 °C) the soda won't freeze.
Answer: The soda won't freeze.
Answer : The pH will be, 3.2
Explanation :
As we known that the value of solubility constant of ferric hydroxide at
is, 
Amount or solubility of iron consumed = (1.800 - 0.3) mg/L = 1.5 mg/L
The given solubility of iron convert from mg/L to mol/L.

The chemical reaction will be:

The expression of solubility constant will be:
![K_{sp}=[Fe^{3+}]\times [3OH^-]^3](https://tex.z-dn.net/?f=K_%7Bsp%7D%3D%5BFe%5E%7B3%2B%7D%5D%5Ctimes%20%5B3OH%5E-%5D%5E3)
Now put all the given values in this expression, we get the concentration of hydroxide ion.
![2.79\times 10^{-39}=(2.7\times 10^{-7})\times [3OH^-]^3](https://tex.z-dn.net/?f=2.79%5Ctimes%2010%5E%7B-39%7D%3D%282.7%5Ctimes%2010%5E%7B-7%7D%29%5Ctimes%20%5B3OH%5E-%5D%5E3)
![[OH^-]=1.5\times 10^{-11}M](https://tex.z-dn.net/?f=%5BOH%5E-%5D%3D1.5%5Ctimes%2010%5E%7B-11%7DM)
Now we have to calculate the pOH.
![pOH=-\log [OH^-]](https://tex.z-dn.net/?f=pOH%3D-%5Clog%20%5BOH%5E-%5D)


Now we have to calculate the pH.

Therefore, the pH will be, 3.2