Question

Calculate the density of oxygen, O2, under each of the following conditions: STP 1.00 atm and 35.0 ∘C
Express your answers numerically in grams per liter. Enter the density at STP first and separate your answers by a comma. density at STP, density at 1 atm and 35.0 ∘C= g/L

Answer 1

Answer:  $d=1.43g/L$ at STP, $d=1.26g/L$ at 1 atm and $35^0C$

Explanation:

To calculate the density of gas, we use the equation given by ideal gas equation:

$PV=nRT$

Number of moles (n) can be written as: $n=\frac{m}{M}$

where, m = given mass

M = molar mass

$PV=\frac{m}{M}RT\\\\PM=\frac{m}{V}RT$

where,

$\frac{m}{V}=d$ which is known as density of the gas

The relation becomes:

$PM=dRT$  

Density at STP :

M = molar mass of oxygen = 32 g/mol

R = Gas constant = $0.0821\text{ L atm }mol^{-1}K^{-1}$

T = temperature of the gas = 273 K  (at STP)

P = pressure of the gas = 1.00 atm  (at STP)

Putting values in equation 1, we get:

$1.00atm\times 32g/mol=d\times 0.0821\text{ L atm }mol^{-1}K^{-1}\times 273K$

$d=1.43g/L$

Density at 1 atm and $35.0^0C$ :

M = molar mass of oxygen = 32 g/mol

R = Gas constant = $0.0821\text{ L atm }mol^{-1}K^{-1}$

T = temperature of the gas = $35^0C=(35+273)K=308K$

P = pressure of the gas = 1.00 atm

Putting values in equation 1, we get:

$1.00atm\times 32g/mol=d\times 0.0821\text{ L atm }mol^{-1}K^{-1}\times 308K$

$d=1.26g/L$