What is the density of CO_2 gas (in g/L) at STP conditions if 2.50 g occupies 5.60 L at 789 torr?

• A. 4.46 g/L
• B. 0.25 g/L
• C. 0.44 g/L
• D. 1.96 g/L

Answer: (D)

Verified step by step guidance

1. Identify the given information: mass of CO_2 gas = 2.50 g, volume = 5.60 L, pressure = 789 torr, and the problem asks for density at STP conditions.
2. Recall that density (\rho) is defined as mass divided by volume: \(\rho = \frac{m}{V}\), where \(m\) is mass and \(V\) is volume.
3. Since the volume given is at 789 torr and not at STP, use the ideal gas law or combined gas law to find the volume the gas would occupy at STP (Standard Temperature and Pressure: 1 atm and 273 K). First, convert pressure from torr to atm: \(P_{initial} = \frac{789}{760}\) atm.
4. Use the combined gas law to find the volume at STP: \(\frac{P_{initial} \times V_{initial}}{T_{initial}} = \frac{P_{STP} \times V_{STP}}{T_{STP}}\). Assume temperature is constant if not given, or use the temperature provided if available. Solve for \(V_{STP}\).
5. Finally, calculate the density at STP using the mass and the new volume: \(\rho_{STP} = \frac{m}{V_{STP}}\). This will give the density in g/L at STP.