The nonvolatile, nonelectrolyte DDT, C14H9Cl5 (354.50 g/mol), is soluble in diethyl ether CH3CH2OCH2CH3. Calculate the osmotic pressure generated when 10.4 grams of DDT are dissolved in 286 ml of a diethyl ether solution at 298 K. The molarity of the solution is M. The osmotic pressure of the solution is atmospheres.

2.50 atm

Explanation:

We have 10.4 g of DDT (solute), whose molar mass is 354.50 g/mol. The corresponding moles are:

10.4 g × (1 mol/354.50 g) = 0.0293 mol

The molarity of the solution is:

M = moles of solute / liters of solution

M = 0.0293 mol / 0.286 L

M = 0.102 M

We can find the osmotic pressure (π) using the following pressure.

π = M × R × T

where,

R: ideal gas constant

T: absolute temperature

π = M × R × T

π = 0.102 M × 0.0821 atm.L/mol.K × 298 K

π = 2.50 atm

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.