Please help with Chemistry,people?

Question

Proceeding down the Noble Gas column on the periodic table, the melting and boiling points of the noble gas elements increases. Neon has higher melting and boiling points than Helium and Krypton has higher melting and boiling points than Neon etc. This shows which of the following:

The nature of ionic bonds.

London Dispersion Forces are stronger between larger diameter atoms whose valence electrons are farther from the nucleus and not as tightly bound.

Hydrogen bonds.

What is the pH of a solution with an [H+] of 0.0001 (moles/L) What is it's pOH?

Answer 1

So here we have a Hydronium molarity of 0.0001 M (Molarity is amount of moles solute per liter solution).

To find the pH of a Hydronium ion, we must take the negative log of it's molarity. Hence:

  

pH = -log [H3O]

     = -log (0.0001)

     = 4.0

When writing the pH, always write the amount of decimal places to the number of Sig Figs. In this case there is one sig fig, so the number is written to the tenths place.

To find the pOH, subtract the pH from 14.00.

14.00 = pH + pOH

pOH = 14.00 - 4.0

pOH = 10.0

Answer 2

Sorry, I'm not too sure about the first part.

However, I can help with the second:

pH = -log[H+]

pH = -log(0.0001)

pH = 4

pOH + pH = 14

pOH = 14 - pH

pOH = 14 - 4

pOH = 10

Hope I helped :)