Answer:
Conductivity meter
Explanation:
All of the other choices measure pH and can tell you when the pH changes, which is how you know the neutralization reaction has occurred. A conductivity meter does not measure pH.
Answer:He 1+
Explanation:
Both Hydrogen atom and helium ion are one electron species. Hence we expect the spectrum of the helium ion to closely resemble that of hydrogen atom also containing one valence electron.