Hey there!
Great question;)
Answer:it is neutrally charged because it has the same number of protons(positively charged iona) and electrons(negatively charged ions)
I hope this helps:)
I'm not going toblie I'm stuck with A and B.
But to me my gut says A
PH indicators detect the presence of H+ and OH-. They do this by reacting with H+ and OH-: they are themselves weak acids and bases. If an indicator is a weak acid and is coloured and its conjugate base has a different colour, deprotonation causes a colour change.
The partial pressure of the gas will be the total pressure minus the vapor pressure. 523.8-23.8=500mmHg. This makes sense due to the fact that the idea of partial pressures still works even with vapor pressure since vapor pressure is just the partial pressure of water vapor (23.8mmHg) in the container which is added to the partial pressure of hydrogen gas (500mmHg) to make a total pressure of 523.8mmHg.
I hope this helps. Let me know in the comments if anything is unclear.
