Calculate the volume (in ml) of 0.170 m naoh that must be added to 389 ml of 0.0543 m 3-(n-morpholino)propanesulfonic acid (mops) to give the solution a ph of 7.55. the pka of mops = 7.18.

3-(n-morpholino)propanesulfonic acid [MOPS] is used as a buffer specially in biological systems

When we add NaOH to it , it forms salt with it and there is a change in the pH of the solution

MOPS + NaOH ---> NaMOPS + H₂O

The Hendersen equation for estimation of pH of a buffer is

pH = pKa + log[salt]/[acid]

7.55 = 7.18 + log[salt]/[acid]

On solving

[salt] / [acid] = 2.344

moles of salt required = 2.344 X moles of acid

initial moles of acid present = 389 X 0.0543 = 21.12 mmoles

let the moles of base added = x mmol

As per equation each mole of base will react with one mole of MOPS

Therefore

moles of salt formed = x mmol

moles of acid left = 21.12-x

x = 2.344 (21.12-x)

x = 49.51 - 2.344x

x = 14.80 mmol

this is the millimoles of base required

So the volume of NaOH needed (mL) = moles / molarity = 14.80/0.170 = 87.05 mL

it is called acid bonding

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.