a 265 ml flask contains pure helium at a pressure of 756 torr. A second flask with a volume of 460 ml contains pure argon at a pressure of713 torr
To find the number of moles of helium and argon in their respective flasks, we can use the ideal gas law equation:
PV = nRT
where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant (0.0821 L·atm/mol·K), and T is the temperature.
Given:
For flask 1 (helium):
- Volume (V1) = 265 mL = 0.265 L
- Pressure (P1) = 756 torr
- Temperature (T) is not explicitly given but assume it is constant
For flask 2 (argon):
- Volume (V2) = 460 mL = 0.460 L
- Pressure (P2) = 713 torr
- Temperature (T) is not explicitly given but assume it is constant
Step 1: Convert pressures to atm
We need to convert the pressures from torr to atm to ensure the unit consistency. 1 atm = 760 torr.
- P1 (helium) = 756 torr / 760 torr/atm = 0.995 atm
- P2 (argon) = 713 torr / 760 torr/atm = 0.937 atm
Step 2: Calculate moles using the ideal gas law equation
For flask 1 (helium):
PV = nRT1
0.995 atm * 0.265 L = n1 * 0.0821 L·atm/mol·K * T1
0.262175 = 0.0821 * n1 * T1
For flask 2 (argon):
PV = nRT2
0.937 atm * 0.460 L = n2 * 0.0821 L·atm/mol·K * T2
0.43022 = 0.0821 * n2 * T2
Step 3: Solve for the number of moles
We can write an equation for n1 and n2 by dividing the two equations:
(0.262175 / 0.0821 * T1) = (0.43022 / 0.0821 * T2)
Since the temperature (T) is constant, we can ignore it in the ratio:
n1/n2 = 0.262175 / 0.43022
n1/n2 = 0.609
Therefore, the ratio of the number of moles of helium (n1) to the number of moles of argon (n2) is approximately 0.609.
Note: We cannot determine the actual number of moles without knowing the temperature or having additional information.