0.249 g of a diatomic element occupies a volume of 125mL at 120 degrees C and 2.00 atm. This element is? Please help. I'm lost.
Use PV = nRT and solve for n = number of mols. Then n = grams/molar mass. You have g and n, solve for molar mass.
Thank you! Sorry about duplicate entries-laptop acting funny.
To determine the identity of the diatomic element, we need to use the ideal gas law equation, which is represented as:
PV = nRT
Where:
P = pressure in atmospheres (atm)
V = volume in liters (L)
n = number of moles (mol)
R = ideal gas constant (0.0821 L·atm/mol·K)
T = temperature in Kelvin (K)
However, the given values are in milliliters and degrees Celsius, so we need to convert them to liters and Kelvin, respectively, to match the units in the ideal gas law equation.
1. Convert volume from milliliters to liters:
Given volume = 125 mL
Since 1 L = 1000 mL, we divide the volume by 1000:
Volume (V) = 125 mL ÷ 1000 = 0.125 L
2. Convert temperature from degrees Celsius to Kelvin:
Given temperature = 120°C
To convert to Kelvin, we add 273.15 to the Celsius temperature:
Temperature (T) = 120°C + 273.15 = 393.15 K
Now that we have the volume (V) = 0.125 L, temperature (T) = 393.15 K, and pressure (P) = 2.00 atm, we can rearrange the ideal gas law equation to solve for the number of moles (n):
n = PV / RT
n = (2.00 atm) * (0.125 L) / (0.0821 L·atm/mol·K * 393.15 K)
By calculating this expression, we can find the number of moles (n). Then, since the problem states that the sample is a diatomic element, we can assume there is only one mole of this element (n = 1 mol) since it does not specify otherwise. Finally, we can determine the molar mass of the element by dividing the given mass (0.249 g) by the number of moles (n). The result will be the molar mass of the diatomic element, which can be used to identify it.