Which of the following statements is true?

the boiling and condensation points of a substance are the same.
the melting and boiling points of a substance are the same.
the freezing and boiling points of a substance are the same.
the heat of fusion for a substance is the energy required to change from the vapor to plasma phase.

Agas mixture with a total pressure of 745 mmhg contains each of the following gases at the indicated partial pressures: co2, 245 mmhg ; ar, 119 mmhg ; and o2, 163 mmhg . the mixture also contains helium gas. part a what is the partial pressure of the helium gas? phe p h e = nothing mmhg request answer part b what mass of helium gas is present in a 10.2-l sample of this mixture at 283 k ? m m = nothing g request answer

The pressure in a fluid is affected by which characteristics of that fluid

What is the percentage of hydrogen in nitrogen trihydride