What method would you use to find the number of moles and mass in grams for each situation listed:
a. 750 cm3 O2 at 27°C and 99.0 kPa
b. 300 cm3 CO2 at -10.0°C and 103kPa
To find the number of moles and mass in grams for each situation, we can use the Ideal Gas Law equation:
PV = nRT
Where:
P = Pressure (in kilopascals, kPa)
V = Volume (in liters, L)
n = Number of moles
R = Ideal gas constant (8.314 J/(mol·K))
T = Temperature (in Kelvin, K)
First, we need to convert the given values to the correct units if necessary.
a. For 750 cm3 O2 at 27°C and 99.0 kPa:
1. Convert cm3 to liters: Since 1 L = 1000 cm3, we have V = 750 cm3 / 1000 = 0.75 L.
2. Convert Celsius to Kelvin: Add 273 to the given temperature to get T = 27°C + 273 = 300 K.
Now we can use the Ideal Gas Law equation:
(99.0 kPa) * (0.75 L) = n * (8.314 J/(mol·K)) * (300 K)
Solving for n, the number of moles:
n = (99.0 kPa * 0.75 L) / (8.314 J/(mol·K) * 300 K)
Calculate the result to get the number of moles.
To find the mass in grams, we need to know the molar mass of O2 (diatomic oxygen), which is 32 g/mol. We can use this to convert moles to grams:
mass = n * molar mass
Calculate the result to find the mass in grams.
b. For 300 cm3 CO2 at -10.0°C and 103 kPa:
1. Convert cm3 to liters: V = 300 cm3 / 1000 = 0.3 L.
2. Convert Celsius to Kelvin: T = -10.0°C + 273 = 263 K.
Using the Ideal Gas Law equation:
(103 kPa) * (0.3 L) = n * (8.314 J/(mol·K)) * (263 K)
Solving for n:
n = (103 kPa * 0.3 L) / (8.314 J/(mol·K) * 263 K)
Calculate the result to find the number of moles.
To find the mass in grams, we need the molar mass of CO2 (carbon dioxide), which is 44 g/mol. Use this value to convert moles to grams:
mass = n * molar mass
Calculate the result to find the mass in grams.