The density of hydrogen at STP is 0.09 g/l. What is the mass of the sample of hydrogen in exercise (36)?
The Correct Answer and Explanation is:
To solve this problem, we need to find the mass of a sample of hydrogen using the given density. The problem refers to Exercise (36), which presumably provides the volume of hydrogen gas. In a previous conversation, you mentioned:
“Three moles of hydrogen occupy a volume of 67.20 L at standard temperature and pressure (STP).”
So, the volume of the hydrogen sample is 67.20 liters, and the density of hydrogen at STP is given as 0.09 g/L.
Step-by-step Calculation:
We use the formula:
Mass = Density × Volume
Mass = 0.09 g/L × 67.20 L
Mass = 6.048 grams
Final Answer:
The mass of the hydrogen sample is 6.048 grams.
Explanation:
Density is a measure of how much mass is contained in a given volume. It is typically expressed in grams per liter for gases at STP. The value 0.09 g/L tells us that each liter of hydrogen weighs 0.09 grams.
Given that the hydrogen sample occupies 67.20 liters, we multiply the density by this volume to find the total mass.
This type of problem involves a straightforward application of the density formula, which is useful in many chemistry calculations, particularly those involving gases. At STP, one mole of an ideal gas occupies 22.4 liters. Since the sample in question contains three moles, the volume is 3 × 22.4 = 67.2 liters, consistent with the volume used here.
Understanding how density relates to mass and volume helps in a variety of scientific fields including chemistry, physics, and environmental science. It also illustrates how gas properties behave under standard conditions, allowing for predictable calculations like this one.
