Determine the molar mass of freon–11 gas if a sample weighing 0.597 g occupies 100. cm3 at 95°c, and 1,000. mmhg (r = 0.08206 l • atm/k • mol, 1 atm = 760 mmhg).

We can first find the number of moles using the ideal gas law equation,
PV = nrT
where P - pressure - 1000 mmHg / 760 mmHg/atm = 1.32 atm 
V - volume -  100 x 10⁻³ L
n - number of moles 
r - universal gas constant - 0.08206 LatmK⁻¹mol⁻¹
T - temperature in Kelvin - 95 °C + 273 = 368 K
substituting these values 
1.32 atm x 100 x 10⁻³ L = n x 0.08206 LatmK⁻¹mol⁻¹ x 368 K
n = 0.00437 mol

molar mass can be determined as follows
molar mass = mass present / number of moles 
molar mass = 0.597 g / 0.00437 mol = 136.6 g/mol
molar mass of gas is 137 g/mol

The disturbance is only parallel to the motion of the wave.

In reversible reaction chemistry equilibrium is attained when the forward and reverse reactions are taking place at the same rate, thus, the concentrations of reactants and products remain the same. a reversible reaction is a chemical reaction where the reactants form products that, in turn, react together to give the reactants back. in irreversible reactions on the other hand, the reactants react to form the products, which cannot revert back into reactants.