Question

What is the pressure, in mmHg, of a 4.50 g sample of O2 gas, which has a temperature of 42.0 °C, and a volume of 2500 mL?

a) 0.615 mmHg

b) 615 mmHg

c) 1.03 mmHg

d) 1030 mmHg

Answer 1

To find the pressure of the given oxygen gas sample, we use the ideal gas law equation, PV = nRT. First, we convert the temperature to Kelvin and the volume to liters. Then, we calculate the number of moles using the mass and molar mass of oxygen. Plugging in the values, we find that the pressure is 467 mmHg.

Step-by-step explanation:

To find the pressure of a gas using the ideal gas law equation, we need to convert the temperature to Kelvin and the volume to liters. First, we convert the temperature from Celsius to Kelvin by adding 273.15 to it: 42.0 °C + 273.15 = 315.15 K. Next, we convert the volume from milliliters to liters by dividing it by 1000: 2500 mL / 1000 = 2.5 L. Now 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, and T is the temperature in Kelvin. Rearranging the equation to solve for P, we have P = (nRT) / V. We are given the mass of the oxygen gas, so we first need to calculate the number of moles using the molar mass of oxygen, which is 32 g/mol. Number of moles = Mass / Molar mass = 4.50 g / 32 g/mol = 0.14 mol. Plugging in the values, P = (0.14 mol * 0.0821 L*atm/mol*K * 315.15 K) / 2.5 L = 0.615 atm. Finally, we convert the pressure from atm to mmHg by multiplying it by 760 mmHg/atm: 0.615 atm * 760 mmHg/atm = 467 mmHg.