Atank has a total pressure of 285 kpa and contains hydrogen, oxygen, carbon dioxide, and neon. if neon has a partial pressure of 14 kpa, carbon dioxide is 13 kpa, and oxygen has a partial pressure of 157 kpa, what is the partial pressure of hydrogen?

Lets the total pressure is Pt and the individual gases are designated as pH2, pCO2, pNe, pO2.

Pt =  pCO2+ pNe+pO2+ pH2

285KPa = 13 KPa+ 14 KPa + 157 KPa +pH2

Now add the partial pressure of CO2, Ne and O2 which is equal to 184 KPa.

285 KPa = 184 KPa + pH2  

Now subtract the individual pressure of each gas from thje total pressure.

285 KPa - 184 KPa = pH2

                101 KPa = pH2

The partial pressure of hydrogen is  101 KPa.

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"

you need to have a picture of the atom that way we can answer it