Final answer:
In organic chemistry, identifying pro-R or pro-S hydrogen atoms involves using the Cahn-Ingold-Prelog priority rules to determine the 3D spatial configuration around a chiral center. Potassium's Latin name is Kalium, and in aqueous solutions, free protons combine with water molecules to form the hydronium ion, H3O+.
Step-by-step explanation:
The question you're asking involves aspects of organic chemistry, specifically the 3D orientation of molecules known as chirality and the classification of hydrogen atoms in a chiral environment as either pro-R or pro-S. These terms are used to describe the spatial position of a hydrogen atom relative to the other substituents around a chiral center. To identify the hydrogens as pro-R or pro-S, you need to look at the molecule's chiral center -- a carbon atom with four different substituents -- and use the Cahn-Ingold-Prelog priority rules.
If you remove each hydrogen atom in question and replace it with a theoretical priority group, you can assign the resulting configuration either an R or an S designation, based on a descending order of priority assigned to the substituents. In propane, the hydrogen atoms attached to the secondary carbon (the two purple ones) can be considered for pro-R/pro-S designation since this carbon is bonded to two other carbons. In 2-methylpropane, the green hydrogen atom is unique because it's attached to a carbon bonded to three other carbons, making it a potential chiral center.
For your other questions: To calculate the number of hydrogen atoms in a compound like C12H22O11, simply look at the molecular formula. The subscript after H indicates that there are 22 hydrogen atoms in one molecule of this compound. The Latin name for the element potassium is Kalium, which is why its chemical symbol is K.
Finally, the discussion surrounding the hydronium ion (H3O+) relates to how protons exist in an aquous solution. Rather than existing as free protons, they are more realistically attached to water molecules, forming hydronium ions.