You select a 150.0 ml volumetric flask to which you add 80.00 mL of a 2.30 M solution of the weak acid you just selected. To finish preparing your buffer you must now add the sodium salt of the conjugate base. How many grams of the sodium salt of your conjugate base must you add so that when you finally fill the flask to the mark with deionized water the buffer will have a pH of 8.50.

7.33 grams of NaOH is the amount of conjugate base added.

Explanation:

given that:

total volume = 150 ml

Vacid = 80 ml

Macid = 2.30 M

Vbase= 150-80= 70ml

Mbase=?

atomic mass of NaOH = 39.99 grams/mole

formula for titration

Macid X Vacid = Mbase X Vbase

putting the values in the equation:

Mbase =

           = 2.62M is the molarity of NaOH

Number of moles of

M =

   2.62 x 0.07 = number of moles

0.1834 moles of NaOH  is there, to know the mass formula used is

mass = number of moles x atomic mass

          =  x 0.1834

           = 7.33 grams of NaOH is the amount of conjugate base added.

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.