At a certain temperature and pressure, 0.30 mol of carbon dioxide has a
volume of 6.7 L. A 6.7 L sample of hydrogen at the same temperature and
pressure
A) has the same mass
B) contains the same number of atoms
C) has a higher density
D) contains the same number of molecules

Option (D). contains the same number of molecules

Explanation:

From the question given, we obtained the following data:

For CO2:

Number of mole = 0.3mol

Volume = 6.7L

For H2:

Volume = 6.7L

Recall 1mole of a gas occupy 22.4L.

1mol of H2 contains 22.4L

Therefore Xmol of H2 will contain 6.7L i.e

Xmol of H2 = 6.7/22.4 = 0.3mol

Since CO2 and H2 have the same number of mole, they will also contain the same number of molecules.

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.