C not sure 100 percent but my best guess
Is A “the density of the ice decreased as it melted”
Acid - base indicators (also known as pH indicators) are substances which change color with pH. They are usually weak acids or bases. you use them if you want to know if a solution is an acid or it it's a base
Answer:
Highest pH(most basic)
Sr(OH)2(aq)
KOH (aq)
NH3(aq)
HF (aq)
HClO4(aq)
Lowest pH(most acidic)
Explanation:
The concentration of H+ ion will determine the pH of a solution. The pH actually reflects the ratio of H+ ion and OH- since both of them can combine into water. Solution with more H+ ion will have a lower pH and called acidic, while more OH- will have high pH and be called basic. Strong acid/base will be ionized more than weak acid/base.
Sr(OH)2(aq) = strong base, release 2 OH- ion per mole
KOH (aq) = Strong base, release 1 OH- per mole
NH3(aq) = weak base, release less than 1 OH- per mole
HF (aq) =strong acid, release 1 H+ per mole
HClO4(aq) = stronger acid, release 1 H+ per mole
