Density of the gas is 3.05 × 10⁻³ g / cm³.
<u>Explanation:</u>
Volume of the cylinder = π r² h
where r is the radius and h is the height of the height or the length of the glass tube.
Here r = 4 cm and h = 27.4 cm
Volume of the cylinder = 3.14 × 4 × 4 × 27.4 = 1376.6 cm³
We have to find the mass of the gas by subtracting the mass of the tube filled with the substance from the mass of the empty tube.
Mass of the substance = 258.5 - 254.3 = 4.2 g
We have to find the density using the formula as,

Plugin the values as,
= 3.05 × 10⁻³ g / cm³
So the Density of the gas is 3.05 × 10⁻³ g / cm³.
Answer:
C₆H₆
Explanation:
Each border of the figure represents 1 atom of carbon. We have 6 borders = 6 atoms of carbon.
Each atom of carbon form 4 bonds. All the carbons are doing a double bond and a single bond with other carbons. That means are bonded 3 times. The other bond (That is not represented in the figure. See the image) comes from hydrogens. As we have 6 carbons that are bonded each 1 with one hydrogen. There are six hydrogens and the molecular formula is:
<h3>C₆H₆</h3>
This structure is: Benzene