how many mole of air are there ina 125 mL flask if the pressure is 739 torr and the temperature is 18 degrees celsius?

To calculate the number of moles of air in the given flask, we can use the ideal gas law equation, which is:

PV = nRT

where:
P = pressure (in atm)
V = volume (in liters)
n = number of moles
R = ideal gas constant (0.0821 L·atm/(mol·K))
T = temperature (in Kelvin)

First, we need to convert the given values to the appropriate units. The pressure is given in torr, so we need to convert it to atm. (1 atm = 760 torr)

Pressure = 739 torr / 760 torr/atm = 0.972 atm

The volume is given in milliliters, so we need to convert it to liters.

Volume = 125 mL / 1000 mL/L = 0.125 L

The temperature is given in degrees Celsius, so we need to convert it to Kelvin.

Temperature (K) = 18°C + 273.15 = 291.15 K

Now we can substitute these values into the ideal gas law equation and solve for the number of moles (n):

(0.972 atm)(0.125 L) = n(0.0821 L·atm/(mol·K))(291.15 K)

0.1215 = n(23.987 L·kPa/(mol·K))

n = 0.1215 / 23.987 ≈ 0.005 A

Therefore, there are approximately 0.005 moles of air in the 125 mL flask.

PV = nRT and solve for n. Don't forget that T must be in kelvin.

0.00508