If the pressure, volume, and the number of moles of a gas are known, which is needed to calculate the universal gas constant from the ideal gas law?
the temperature of the gas
the molar volume of the gas
the molar mass of the gas
the partial pressure of the gas

 the temperature of the gas

Explanation: The ideal gas law has arrived from the combination of four laws:

1) Boyle's Law: This law states that pressure is inversely proportional to the volume of the gas at constant temperature and number of moles.

    (At constant temperature and number of moles)

2) Charles' Law: This law states that volume is directly proportional to the temperature of the gas at constant pressure and number of moles.

   (At constant pressure and number of moles)

3) Gay-Lussac's Law: This law states that pressure is directly proportional to the temperature of the gas at constant volume and number of moles.

    (At constant volume and number of moles)

4) Avogadro's Law: This law states that volume is directly proportional to the number of moles of the gas at constant pressure and temperature.

  (At constant temperature and pressure)

According to ideal gas law,

where,

P = pressure of the gas

V = volume of the gas

T = temperature of the gas

n = number of moles of gas

R = Gas constant

Thus to calculate the gas constant we need to know the temperature of gas.

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

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~ trueboss72