Molar mass Argon = 39.948 g/mol
1 mol ------ 39.948 g
mol ----- 20.0 g
mol = 20.0 * 1 / 39.948
= 0.5006 moles
1 mol --------------------- 22.4 L ( at STP )
0.5006 moles ------------- L
L = 0.5006 * 22.4
= 11.21 L
hope this helps!
Answer:
The molar mass of the organic solid is 120.16 g/mol.
The molecular formula of an organic solid is 
Explanation:
Let the molecular mass of an organic solid be 


where,
=Elevation in boiling point = 
Mass of organic solid= 0.561 g
Mass of diphenyl = 24.9 g = 0.0249 kg (1 kg = 1000 g)
= boiling point constant = 8.00 °C/m
m = molality
Now put all the given values in this formula, we get



Percentage of carbon in an organic solid = 40.0%

x = 4.0
Percentage of hydrogen in an organic solid = 6.7%

y = 8.0
Percentage of hydrogen in an organic solid = 6.7%

y = 4.0
The molecular formula of an organic solid is 
Answer: D.
Explanation: A chemical reaction is said to be in a state of equilibrium when the rate of the forward reaction equals the rate of the backward reaction, thus, there is no net change in the concentration of reactants and products.