How many moles of air are there in flask with a volume of 125mL if the pressure is 745 mm Hg and the temperature is 22 celcius ?

PV=nRT solve for n

To determine the number of moles of air in a flask, we will use the ideal gas law equation: PV = nRT.

First, we need to convert the given values to appropriate units:
- The volume of the flask is given as 125 mL. We need to convert it to liters by dividing by 1000: 125 mL ÷ 1000 = 0.125 L.
- The pressure is given as 745 mm Hg. We need to convert it to atmospheres (atm) by dividing by 760: 745 mm Hg ÷ 760 = 0.979 atm.
- The temperature is given as 22 Celsius. We need to convert it to Kelvin by adding 273.15: 22 + 273.15 = 295.15 K.

Now, we can substitute the values into the ideal gas law equation:
(0.979 atm) * (0.125 L) = n * (0.0821 L·atm/mol·K) * (295.15 K)

Simplifying the equation:
0.1223755 = n * 24.205315

To solve for n, divide both sides of the equation by 24.205315:
n = 0.1223755 / 24.205315

Calculating the value of n:
n ≈ 0.00505 moles

Therefore, there are approximately 0.00505 moles of air in the flask.