Answer:
We can use the Ideal Gas Law to determine the number of moles of gas in each situation:
PV = nRT
where P is the pressure of the gas in atmospheres (atm), V is the volume of the gas in liters (L), n is the number of moles of gas, R is the ideal gas constant (0.0821 L atm/mol K), and T is the temperature of the gas in Kelvin (K).
A. For 1.25 L of gas at 250.0 K and 1.06 atm, we can substitute the given values into the Ideal Gas Law equation:
(1.06 atm) (1.25 L) = n (0.0821 L atm/mol K) (250.0 K)
Solving for n, we get:
n = (1.06 atm) (1.25 L) / [(0.0821 L atm/mol K) (250.0 K)] = 0.0646 moles
Therefore, there are 0.0646 moles of gas in 1.25 L at 250.0 K and 1.06 atm.
B. For 800 mL (0.8 L) of gas at 27°C (300 K) and 0.925 atm, we need to convert the temperature to Kelvin before substituting into the Ideal Gas Law equation:
(0.925 atm) (0.8 L) = n (0.0821 L atm/mol K) (300 K)
Solving for n, we get:
n = (0.925 atm) (0.8 L) / [(0.0821 L atm/mol K) (300 K)] = 0.030 moles
Therefore, there are 0.030 moles of gas in 800 mL at 27°C and 0.925 atm.