Calculate the density (g/L) of 478 mL of krypton at 47 degrees C and 671 mmHg.
I wasn't sure about this one but I got:
density = 2820 g/L with sig figs
Density = 2.82 g/L
Nope. Right digits but wrong decimal.
By the way, the problem below with an answer of 0.530 is ok but the site wouldn't let me post an ok.
I want to point out that you aren't allowed 4 significant figures.
right
To calculate the density of a gas at a given temperature and pressure, we can use the ideal gas law equation:
PV = nRT
Where:
P is the pressure in units of pressure (in this case, mmHg)
V is the volume in units of liters (in this case, mL converted to L)
n is the number of moles of the gas
R is the ideal gas constant (0.0821 L.atm/mol.K or 8.314 J/mol.K)
T is the temperature in units of Kelvin (in this case, Celsius converted to Kelvin)
First, let's convert the volume from mL to L:
478 mL = 478/1000 L = 0.478 L
Next, let's convert the temperature from Celsius to Kelvin:
47 degrees C + 273.15 = 320.15 K
Now, let's convert the pressure from mmHg to atm (using the in box method):
1 atm = 760 mmHg
671 mmHg * (1 atm/760 mmHg) = 0.8816 atm
Now, we can rearrange the ideal gas law equation to solve for density:
density = (PM)/(RT)
Where:
P is the pressure in atm
M is the molar mass of the gas (in this case, krypton)
R is the ideal gas constant (in units of L.atm/mol.K)
T is the temperature in Kelvin
The molar mass of krypton is 83.80 g/mol.
Plugging in the values:
density = (0.8816 atm * 83.80 g/mol) / (0.0821 L.atm/mol.K * 320.15 K)
Calculating this, the density comes out to be approximately 2.817 g/L.