Calculate the relative molecular mass of a gas if a 500cm3 sample at 20¢ªC and 1 atomic mass of 0.66g
1 atmosphere=101.325 kpa
Use this to work out the pascal value and then use the ideal gas equation to find out the moles.
Once you have done this use the n=m/M equation to find out what the relative molecular mass is :)
I don't understand the "1 atomic mass of 0.66 g."
To calculate the relative molecular mass (Mr) of a gas, you need to know the volume of the sample (V), the temperature (T), and the mass of the sample (m).
Here's the step-by-step calculation:
1. Convert the sample volume from cm³ to m³:
V = 500 cm³ = 500 * 10^(-6) m³ = 0.0005 m³
2. Convert the temperature from ¢ªC to Kelvin:
T = 20 ¢ªC + 273.15 = 293.15 K
3. Calculate the number of moles using the ideal gas law equation:
n = PV / RT
where P is the pressure (given as 1 atm), R is the ideal gas constant (0.0821 L·atm/(mol·K)), and T is the temperature in Kelvin.
n = (1 atm * 0.0005 m³) / (0.0821 L·atm/(mol·K) * 293.15 K)
4. Calculate the mass of the sample in grams using the given atomic mass (molar mass) of 0.66 g/atom:
m = n * molar mass
The molar mass is also known as the atomic mass of the gas.
m = n * 0.66 g
Remember, 1 mole of any substance contains Avogadro's number (6.022 x 10^23) of particles. Therefore, the mass of one mole of any substance is equal to its molar mass (atomic mass) in grams.
5. Substitute the value of n into the above equation:
m = (1 atm * 0.0005 m³) / (0.0821 L·atm/(mol·K) * 293.15 K) * 0.66 g
6. Calculate the relative molecular mass (Mr) using the formula:
Mr = m / n
Mr = ((1 atm * 0.0005 m³) / (0.0821 L·atm/(mol·K) * 293.15 K) * 0.66 g) / n
Now, you can calculate the value of relative molecular mass (Mr) using the given information and the above calculations.