Benzene equals 78.11 grams/mole

Is that a question? My on-line calculator says it is 78.114 g/mol.

19. Convert 15 ppm of benzene to mg/m3 at 20 oC and 720 torr

Density of a gas is g/L = P(MW)/RT

(740 torr x 1 atm/760torr)(78.114g/mole)/ (.0821L atm/mole K)(293K) = 3.16g/L

1ppm =1 L Benzene/106 L of air = 1L ben/1000 m of air = 0.001 L ben/m3 = 0.00316 g/m3
x/3.16=15 = 47.4mg/m3 ???

To determine the molar mass of benzene, you need to know the atomic masses of the elements it contains: carbon (C) and hydrogen (H). Here's how you can calculate it:

1. Determine the number of each element in the molecular formula of benzene, which is C6H6.

Benzene has 6 carbon atoms (C) and 6 hydrogen atoms (H).

2. Find the atomic masses of carbon (C) and hydrogen (H) from the periodic table.

The atomic mass of carbon is approximately 12.01 grams/mol, and the atomic mass of hydrogen is approximately 1.01 grams/mol.

3. Multiply the number of atoms for each element by their respective atomic masses.

For carbon:
6 (number of carbon atoms) x 12.01 (atomic mass of carbon) = 72.06 grams/mol

For hydrogen:
6 (number of hydrogen atoms) x 1.01 (atomic mass of hydrogen) = 6.06 grams/mol

4. Add the individual masses together to find the molar mass of benzene.

72.06 grams/mol (carbon) + 6.06 grams/mol (hydrogen) = 78.12 grams/mol

Therefore, the molar mass of benzene is approximately 78.12 grams/mol.