#4 and #5:
To find pH given concentration of H+ or H30+
pH = - log (H+ or H30+ M)
To find pH given concentration of OH-
Since you already found the pH for this (in #4), you subtract #4's answer from 14.
14 - (pH) = pOH
Because it is made up of sodium, a metal, and carbon, a nonmetal.
Hope I helped ♡
The third question requires you to solve for the weight of sodium (Na) and weight of Chloride (Cl) from the calculated moles of each element Na, and Cl.
So, you need to multiply the calculated moles of Na with its molar mass (23 g/ mol) to get the answer for Na. And multiply the calculated moles of Cl with its molar mass (35.45 g/mol) to get the answer for Cl.
Explanation:
The structure of Ferrarrisite Ca5(HAs O4)2(AsO4)2
Three elements that are likely to have similar chemical and physical properties are