Final answer:
To determine the mass of a gas sample with a given volume of 22 L and density of 1.35 g/L at STP, multiply the volume by the density to get 29.7 g. The mass expressed with the correct number of significant figures is 30 g.
Step-by-step explanation:
The question involves calculating the mass of a gas sample given its volume and density under Standard Temperature and Pressure (STP) conditions. The formula to determine the mass of a substance is the product of its volume and density. Therefore, the mass (m) of the gas sample can be found by multiplying its volume (V) by its density (p):
m = V × p
Given that the volume (V) of the gas is 22 L and the density (p) is 1.35 g/L, the mass of the gas is calculated as follows:
m = 22 L × 1.35 g/L = 29.7 g
Using correct significant figures, the final answer is expressed as 30 g, since the volume was given to two significant figures and the density was given to three. When performing the multiplication, the number of significant figures in the result is based on the measurement with the fewest significant figures.
It is important to note that this calculation assumes that the ideal gas occupies 22.4 L per mole at STP, as inferred from the ideal gas law. However, we are using the provided volume of 22 L for this specific question to calculate the mass based on density.